The two-component solid forms involving 4,4'-methylene-bis(benzenamine) included both salts and co-crystals,while 4,4'methylene-bis(benzenamine) crystallized exclusively as a salt,in agreement with the differe...The two-component solid forms involving 4,4'-methylene-bis(benzenamine) included both salts and co-crystals,while 4,4'methylene-bis(benzenamine) crystallized exclusively as a salt,in agreement with the differences in the pK a values.Many of the crystal structures displayed either the neutral or the ionic form of the carboxylic acid-amino heterosynthon,and the similarity in crystal structures between the neutral and the ionized molecules makes the visual distinction between a salt and co-crystal dependent on the experimental location of the acidic proton.A variety of supramolecular hydrogen bonded motifs involving interactions between the aza molecules and carboxylic acid groups are observed rather than just the O-H···N/O-H···O motif.The motifs are identical in all the two compounds analyzed showing the robustness of these supramolecular synthons.In all adducts,recognition between the constituents is established through either N-H···O and/or O-H···O/O-H···N pairwise hydrogen bonds.In all adducts,COOH functional groups available on 1 and 2 interact with the N-donor compounds.The COOH moieties in 1 forms only single N-H···O hydrogen bonds,whereas in 2,it forms pairwise O-H···N/N-H···O hydrogen bonds.The supramolecular architectures are elegant and simple,with stacking of networks in 2,but a rather complex network with a threefold interpenetration pattern was found in 1.Thermal stability of these compounds has been investigated by thermogravimetric analysis(TGA) of mass loss.展开更多
Imidazole base was crystallized with different aromatic carboxylic acids 2,4-dihydroxybenzoic acid, 5-chlorosalicylic acid, and 1,8-naphthalic acid, affording three new binary molecular organic salts of [(C 3 H 5 N 2 ...Imidazole base was crystallized with different aromatic carboxylic acids 2,4-dihydroxybenzoic acid, 5-chlorosalicylic acid, and 1,8-naphthalic acid, affording three new binary molecular organic salts of [(C 3 H 5 N 2 + )·(C 7 H 5 O 4 )] (1), [(C 3 H 5 N 2 + )·(C 7 H 4 O 3 Cl )] C 7 H 5 O 3 Cl (2), and [(C 3 H 5 N 2 + ) (C 12 H 7 O 4 )] (3). Proton transfer occurs from the COOH of carboxylic acid to nitrogen of imidazole in all complexes (1-3), leading to the hydrogen bond N-H…O in all structures. To our knowledge, the recognition pattern between the carboxylic acid group and imidazole (acid-imidazole synthon) is less well-studied so far. The cooperation among COOH, COO and imidazolium cation functional groups for the observed hydrogen bond synthons is examined in the three structures. Generally, the strong N-H…O and O-H…O hydrogen bonds define supramolecular architecture and connectivity within chains, while weaker C-H…O hydrogen bonds play the dominant role in controlling the interactions between layers in these novel organic salts. Thermal stability of these compounds has been investigated by thermogravimetric analysis (TGA) of mass loss.展开更多
Multifunctional molecules are capable of assembling via different supramolecular synthons, or hydrogen bond motifs, between the same or different functional groups, leading to the possibility of cocrystal. Utilization...Multifunctional molecules are capable of assembling via different supramolecular synthons, or hydrogen bond motifs, between the same or different functional groups, leading to the possibility of cocrystal. Utilization of the interplay of dimensionality （I-D, 2-D and 3-D）, orientation of functional groups of the building blocks, influence of rigid/flexible linking groups, and weak interactions provides an interesting route for the creation of novel supramolecular architectures in the crystal lattice. N-unsubstituted 1H-benzotriazole and carboxylic acid, being self-complementary molecules, offer a broad scope of study of binary compounds based on the complementary combination of H-bonding/donating sites. We report here the construction of three extended molecular networks in cocrystals of the carboxylic acid group of the acid and the 1H-benzotriazole triazole moiety. We have been able to identify four major supramolecualr synthons that would be helpful in the prediction of structural motifs for these kinds of studies. Interestingly, these heterosynthons are strikingly similar, to those of the homosynthons of the individual functional groups. The nature of the aza groups helps to enhance the overall volume of the crystal lattice thus lead- ing to the formation of various supramolecular assemblies. Thermal stability of these compounds has been investigated by thermogravimetric analysis （TGA） of mass loss.展开更多
The results of crystallographic analyses on 1：1 and 1：4 well-defined co-crystals formed between glycine anhydride and each of 4-hydroxybenzoic acid and 3,5-dihydroxybenzoic acid are described. Neutral molecules are ...The results of crystallographic analyses on 1：1 and 1：4 well-defined co-crystals formed between glycine anhydride and each of 4-hydroxybenzoic acid and 3,5-dihydroxybenzoic acid are described. Neutral molecules are connected via heteromeric O-H.-.O and N-H…O contacts leading to different packing arrangements of supramolecular chains. On the basis of the molec- ular structures of glycine anhydride and carboxylic acid vips, the hydrogen bonds are arranged to give centrosymmetric synthons V and VII which are noteworthy for their robustness. Hydrogen-bond interactions between glycine anhydride and aromatic acid provide sufficient driving force to direct molecular recognition and crystal packing. Utilization of the orientation of functional groups of the building blocks, the acidity, and weak interactions provides a route for the creation of novel supra- molecular architectures in the crystal lattice. Both two co-crystals contain the expected hydrogen-bonded motifs, and there has been no proton transfer from either of the two carboxylic acids to the aza compound moiety. This demonstrates that glycine anhydride is very capable of affecting the construction of binary co-crystals in a predictable and rationale manner. It is noted that synthons Ⅷ and IX are fairly large, but the real challenge in crystal engineering is to find a big enough synthon that occurs often enough. Thermal stability of these compounds has been investigated by thermogravimetric analysis （TGA） of mass loss.展开更多
Carbon dioxide reduction, as a sustainable and versatile strategy for the access of chemical fuels, has attracted increasing attention and enormous efforts have been devoted to it in recent years. However, employing c...Carbon dioxide reduction, as a sustainable and versatile strategy for the access of chemical fuels, has attracted increasing attention and enormous efforts have been devoted to it in recent years. However, employing carbon dioxide as double synthons via bimolecular reduction remains challenging. Here, by leveraging the bimolecular reduction of carbon dioxide to carbonyl and methyl respectively, we describe a Pd-catalyzed trifunctionalization of alkynes with aryl iodide for the first time and showcase its advantages on the formation of various β-diketones and their application in the constructing of heterocyclic compounds with important biological activity, including pyrimidine, oxazole, pyrazole.展开更多
The first diastereodivergent formal[4+1]cycloaddition reactions of azoalkenes with p-quinone methides(pQMs)have been accomplished.The reported reaction occurred via a domino oxa-1,4-addition/1,6-addition process,allow...The first diastereodivergent formal[4+1]cycloaddition reactions of azoalkenes with p-quinone methides(pQMs)have been accomplished.The reported reaction occurred via a domino oxa-1,4-addition/1,6-addition process,allowing the use of common azoalkenes as C1 synthons.A broad range of 2,3-dihydrobenzofurans was smoothly prepared in good yields and with reversible diastereoselectivities.The steric hindrance and hydrogenbonding interaction were proposed to account for the two different modes of diastereo-control.The projected reaction features the employment of azoalkene as carbene-like C1 synthon,mild conditions,broad substrate scope and tunable diastereoselectivity.展开更多
The synthesis and aggregation behavior of two glycoluril derivatives were descrybed.The crystal of compound 1 belongs to the triclinic system,space group ■,with a=8.946（1）,b=13.445（2）,c=20.361（3）?,α=89.517（3...The synthesis and aggregation behavior of two glycoluril derivatives were descrybed.The crystal of compound 1 belongs to the triclinic system,space group ■,with a=8.946（1）,b=13.445（2）,c=20.361（3）?,α=89.517（3）,β=84.405（3）,γ=86.325（3）°,Z=2,V=2432.1（6）?3,Dc=1.293 g·cm-3,C48H34N6O6·2DMSO,Mr=947.07,F（000）=992,μ=0.170 mm-1,the final R=0.1606 and wR=0.2410 for 4382 observed reflections（Ⅰ>2σ（Ⅰ））.The crystal of compound 2belongs to the monoclinic system,space group P21/c,with a=9.500（3）,b=24.522（8）,c=17.997（6）?,Z=2,V=4054（2）?3,Dc=1.296 g·cm-3,C48H34N6O6,Mr=790.81,F（000）=1648,μ=0.087mm-1,the final R=0.2146 and wR=0.2535 for 2878 observed reflections（Ⅰ>2σ（Ⅰ））.Unlike the highly conserved R22（8）hydrogen-bonding amide···amide homosynthon,the structural analysis indicated that compound 1 selected the C（20）hydrogen-bonding motif and 2 selected the R22（34）hydrogen-bonding motif,which revealed the competition from remote solvent molecule and the interference of the molecular hydrocarbon core in crystal packing.The supramolecular structure revealed molecule 1 is further linked into a one-dimensional chain and 2 into a two-dimensional interwoven plane by N–H···N hydrogen bonds.展开更多
Diversity-oriented synthesis is a powerful and interesting synthetic tool for the rapid construction of structurally complex and privileged scaffolds from readily accessible starting materials.To date,diversity-orient...Diversity-oriented synthesis is a powerful and interesting synthetic tool for the rapid construction of structurally complex and privileged scaffolds from readily accessible starting materials.To date,diversity-oriented synthesis mostly relies on the employment of versatile reagents.Versatile reagents can be regulated as controllable and flexible building blocks for multipurpose utilizations.Over the past decade,a variety of multifunctional reagents have been developed.However,most versatile reagents usually need multi-step synthesis,thus restricting their wide application to a large extent.In terms of the practicalities and universalities,we prefer to pay more attention to the utilization of simple and practical versatile reagents with multiple reactivities,mainly including atropaldehyde acetals,aryl methyl ketones,vinylene carbonate,vinyl azides,aryldiazonium salts,rongalite,halodifluoromethyl compounds.Most importantly,these versatile reagents can also play different roles simultaneously in the same reaction,in which their different reactivities are converged into the final target products.Such strategy can not only offer more possibilities for the synthesis of several active pharmaceutical ingredients,but also minimize the occurrence of some side reactions by lessening the varieties of materials.Also,a perspective is given at the end of this review.展开更多
From natural tartaric acid, (R)-2-benzyloxy-3-(2-tetrahydropyranyloxy) propanol 3 was designed and synthesized, and (R)-2-benzyloxy-3-(4-methoxybenzyloxy) propanol 7 was prepared in a new method. They can be used as ...From natural tartaric acid, (R)-2-benzyloxy-3-(2-tetrahydropyranyloxy) propanol 3 was designed and synthesized, and (R)-2-benzyloxy-3-(4-methoxybenzyloxy) propanol 7 was prepared in a new method. They can be used as chiral synthons of lysophosphatidic acid and other compounds with asymmetric propanetriol backbone.展开更多
A quinine-derived thiourea-catalyzed inter-/intramolecular Michael cycloaddition of chromoneoxindole/benzofuranone synthons with 3-substituted methylenebenzofuranones has been established,which constructed enantiomeri...A quinine-derived thiourea-catalyzed inter-/intramolecular Michael cycloaddition of chromoneoxindole/benzofuranone synthons with 3-substituted methylenebenzofuranones has been established,which constructed enantiomerically pure bispiro[benzofuran-oxindole/benzofuran-chromanone]s bearing five consecutive stereocenters including two spiro quaternary carton centers in good yields(up to 93%) with high diastereoselectivities(up to>20:1 dr) and good enantioselectivities(up to>99% ee).Moreover,this is the first example of bifunctional chromone-benzofuranone synthon directed organocatalytic tandem reaction,and also the first example of the bispiro[benzofuran-oxindole] and bispirobenzofuranone,potentially useful in medicinal chemistry.展开更多
This essay discusses some preliminary thoughts on the development of a rational and modular approach for molecular design in soft matter engineering and proposes ideas of structural and functional synthons for advance...This essay discusses some preliminary thoughts on the development of a rational and modular approach for molecular design in soft matter engineering and proposes ideas of structural and functional synthons for advanced functional materials. It echoes the Materials Genome Initiative by practicing a tentative retro-functional analysis （RFA） scheme. The importance of hierarchical structures in transferring and amplifying molecular functions into macroscopic properties is recognized and emphasized. According to the role of molecular segments in final materials, there are two types of building blocks： structural synthon and functional synthon. Guided by a specific structure for a desired function, these synthons can be modularly combined in various ways to construct molecular scaffolds. Detailed molecular structures are then deduced, designed and synthesized precisely and modularly. While the assembled structure and property may deviate from the original design, the study may allow further refinement of the molecular design toward the target function, The strategy has been used in the development of soft fullerene materials and other giant molecules. There are a few aspects that are not yet well addressed： （1） function and structure are not fully decoupled and （2） the assembled hierarchical structures are sensitive to secondary interactions and molecular geometries across different length scales. Nevertheless, the RFA approach provides a starting point and an alternative thinking pathway by provoking creativity with considerations from both chemistry and physics. This is particularly useful for engineering soft matters with supramolecular lattice formation, as in giant molecules, where the synthons are relatively independent of each other.展开更多
A metal-free cross coupling between common CH2Cl2 and carboxylic acids has been achieved with K2CO3 as the sole additive. This simple protocol is a convenient and cost-effective route to synthesize methylene diesters ...A metal-free cross coupling between common CH2Cl2 and carboxylic acids has been achieved with K2CO3 as the sole additive. This simple protocol is a convenient and cost-effective route to synthesize methylene diesters from a wide scope of carboxylic acids substrates with good functional group tolerance. Several gram-scale reactions have been performed to evaluate the effectiveness and practicality of this protocol.展开更多
The virtual cocrystal screening approach based on molecular electrostatic potential surface(MEPS)maps is a fast and feasible computational method to estimate the probability of cocrystal formation by calculating the d...The virtual cocrystal screening approach based on molecular electrostatic potential surface(MEPS)maps is a fast and feasible computational method to estimate the probability of cocrystal formation by calculating the difference in the interaction site pairing energies of monomers and that of their assemblies prior to experimental screening.In this paper,we report 12 cocrystal forms of temozolomide with mono-,di-,and trihydroxy benzoic acids,namely,3-hydroxy-,2,4-dihydroxy-,2,5-dihydroxy-,2,6-dihydroxy-,3,4-dihydroxy-,and 3,4,5-trihydroxy-benzoic acids,as well as benzoic acid,as pharmaceutical coformers for the first time.10 single crystals out of the 12 cocrystal forms were obtained and unequivocally determined by single-crystal X-ray diffraction,which clarified spatial arrangements,molecular conformations,and supramolecular synthons.MEPS further gains some insights into the sites of hydrogen bonding interactions for exploring combination patterns in these assemblies.Modulated stability of TMZ was successfully achieved by cocrystallization with these acids.展开更多
Carbon dioxide(CO_(2))is an attractive C1 building block in chemical synthesis due to its abundance,availability and sustainability.However,the low reactivity and high stability generally limits its transformations un...Carbon dioxide(CO_(2))is an attractive C1 building block in chemical synthesis due to its abundance,availability and sustainability.However,the low reactivity and high stability generally limits its transformations under mild conditions to value added chemicals.Recent advances in flow chemistry provide effective means for the chemical transformation of CO_(2),and many new methods and techniques that fully utilized the advantages of continuous flow platforms for the chemical fixation of CO_(2)have been realized.In view of the rapid development and the urgent need for continuous transformation of CO_(2),herein we wish to present an update of the recent advances in this research area.展开更多
A C/D ring synthon of vitamin D is readily obtained from cholesteryl acetate via oxidation, elimination of acetoxy group and Norrish type II photochemical reaction.
A selective ring-opening [3+2] cyclization reaction of benzo[d]isoxazoles with 2-bromo-propanamides has been developed.The azaoxyallyl cation intermediates are employed as C^O 3-atom synthon to build oxa-heterocycles ...A selective ring-opening [3+2] cyclization reaction of benzo[d]isoxazoles with 2-bromo-propanamides has been developed.The azaoxyallyl cation intermediates are employed as C^O 3-atom synthon to build oxa-heterocycles via the selectivity of suitable cyclization partners.This transformation provides rapid access to highly functionalized 2-hydroxyaryl-oxazolines under mild conditions and excellent regioselectivity.展开更多
The construction of an unprecedented intertwined spiral solvent channel is driven by weak C–Cl…O and C–H…N interactions based on extraordinary parallel spirals which were structured from supramolecular synthon mac...The construction of an unprecedented intertwined spiral solvent channel is driven by weak C–Cl…O and C–H…N interactions based on extraordinary parallel spirals which were structured from supramolecular synthon macrocycle 1（C44H44N4O4） with a propargylamine backbone. The product is characterized by ^1H NMR, ^13C NMR, IR and HRMS, and further confirmed by single-crystal X-ray diffraction. It crystallizes in the monoclinic system, space group C2/c, with a = 28.922（3）, b = 8.5069（9）, c = 21.687（2）A^°, β = 130.6320（10）°, V = 4049.4（7） A^°3 and Z = 8. A total of 11874 reflections were collected, of which 4942 were independent（Rint = 0.0590） and 2937 were observed with I 〉 2σ（I）. The final full-matrix least-squares refinement gave R（I 〉 2s（I）） = 0.069 and w R = 0.167, S = 1.05,（Δρ）max = 0.20 and（Δρ）min =-0.22 e·A^1-3. The fluorescence of the product is discussed.展开更多
An efficient synthesis of functionalized 6-decalone 16, starting from a dienolate anion 3a via a tandem Michael reaction, is described. 16 could be used as a potential intermediate for synthesis of drimane related ses...An efficient synthesis of functionalized 6-decalone 16, starting from a dienolate anion 3a via a tandem Michael reaction, is described. 16 could be used as a potential intermediate for synthesis of drimane related sesquiterpenes.展开更多
Benzotriazole,N,N'-dimethylpiperazine and N-methylpiperazine were applied to crystallize with 5-sulfosalicylic acid(5-H2SSA),affording three new binary molecular cocrystals [(C6H6N3+).(C7H5O6S-)].H2O(1),[(C6H16N22...Benzotriazole,N,N'-dimethylpiperazine and N-methylpiperazine were applied to crystallize with 5-sulfosalicylic acid(5-H2SSA),affording three new binary molecular cocrystals [(C6H6N3+).(C7H5O6S-)].H2O(1),[(C6H16N22+)1/2.(C7H5O6S-)].H2O(2) and [(C5H14N22+).(C7H5O6S-)2].3H2O(3) under general conditions.Proton-transferring occurs from acid to nitrogen of N-donor compounds in all compounds 1,2 and 3.Analysis of the hydrogen-bonding synthons and their effects on crystal packing were also presented in the context of crystal engineering and host-vip chemistry.In compound 1,1-D infinite chains are extended to a 2-D layered architecture via strong O-H...O hydrogen bonds and then to a 3-D network by N-H...O interactions.Compound 2 and 3 both have the 1-D chain which is formed by O-H...O bonds and weak C-H...O hydrogen bonds.A common intramolecular S(6) [synthon I] ring is formed by the hydroxyl with the carboxyl group in all three compounds.展开更多
基金supported by the National Natural Science Foundation of China(20701023 and 21172127)the Natural Science Foundation of Shandong Province,China(BS2010NJ004, 2009ZRB019KH)
文摘The two-component solid forms involving 4,4'-methylene-bis(benzenamine) included both salts and co-crystals,while 4,4'methylene-bis(benzenamine) crystallized exclusively as a salt,in agreement with the differences in the pK a values.Many of the crystal structures displayed either the neutral or the ionic form of the carboxylic acid-amino heterosynthon,and the similarity in crystal structures between the neutral and the ionized molecules makes the visual distinction between a salt and co-crystal dependent on the experimental location of the acidic proton.A variety of supramolecular hydrogen bonded motifs involving interactions between the aza molecules and carboxylic acid groups are observed rather than just the O-H···N/O-H···O motif.The motifs are identical in all the two compounds analyzed showing the robustness of these supramolecular synthons.In all adducts,recognition between the constituents is established through either N-H···O and/or O-H···O/O-H···N pairwise hydrogen bonds.In all adducts,COOH functional groups available on 1 and 2 interact with the N-donor compounds.The COOH moieties in 1 forms only single N-H···O hydrogen bonds,whereas in 2,it forms pairwise O-H···N/N-H···O hydrogen bonds.The supramolecular architectures are elegant and simple,with stacking of networks in 2,but a rather complex network with a threefold interpenetration pattern was found in 1.Thermal stability of these compounds has been investigated by thermogravimetric analysis(TGA) of mass loss.
基金supported by the National Natural Science Foundation of China (20701023, 20971076)the Natural Science Foundation of Shandong Province, China (BS2010NJ004,2009ZRB019KH)
文摘Imidazole base was crystallized with different aromatic carboxylic acids 2,4-dihydroxybenzoic acid, 5-chlorosalicylic acid, and 1,8-naphthalic acid, affording three new binary molecular organic salts of [(C 3 H 5 N 2 + )·(C 7 H 5 O 4 )] (1), [(C 3 H 5 N 2 + )·(C 7 H 4 O 3 Cl )] C 7 H 5 O 3 Cl (2), and [(C 3 H 5 N 2 + ) (C 12 H 7 O 4 )] (3). Proton transfer occurs from the COOH of carboxylic acid to nitrogen of imidazole in all complexes (1-3), leading to the hydrogen bond N-H…O in all structures. To our knowledge, the recognition pattern between the carboxylic acid group and imidazole (acid-imidazole synthon) is less well-studied so far. The cooperation among COOH, COO and imidazolium cation functional groups for the observed hydrogen bond synthons is examined in the three structures. Generally, the strong N-H…O and O-H…O hydrogen bonds define supramolecular architecture and connectivity within chains, while weaker C-H…O hydrogen bonds play the dominant role in controlling the interactions between layers in these novel organic salts. Thermal stability of these compounds has been investigated by thermogravimetric analysis (TGA) of mass loss.
基金supported by the National Natural Science Foundation of China (20701023 and 20971076)the Natural Science Foundation of Shandong Province,China (BS2010CL013 and2009ZRB019KH)
文摘Multifunctional molecules are capable of assembling via different supramolecular synthons, or hydrogen bond motifs, between the same or different functional groups, leading to the possibility of cocrystal. Utilization of the interplay of dimensionality （I-D, 2-D and 3-D）, orientation of functional groups of the building blocks, influence of rigid/flexible linking groups, and weak interactions provides an interesting route for the creation of novel supramolecular architectures in the crystal lattice. N-unsubstituted 1H-benzotriazole and carboxylic acid, being self-complementary molecules, offer a broad scope of study of binary compounds based on the complementary combination of H-bonding/donating sites. We report here the construction of three extended molecular networks in cocrystals of the carboxylic acid group of the acid and the 1H-benzotriazole triazole moiety. We have been able to identify four major supramolecualr synthons that would be helpful in the prediction of structural motifs for these kinds of studies. Interestingly, these heterosynthons are strikingly similar, to those of the homosynthons of the individual functional groups. The nature of the aza groups helps to enhance the overall volume of the crystal lattice thus lead- ing to the formation of various supramolecular assemblies. Thermal stability of these compounds has been investigated by thermogravimetric analysis （TGA） of mass loss.
基金financially supported by the National Natural Science Foundation of China (20701023, 51102138)the Natural Science Foundation of Shandong Province, China (BS2010NJ004,2009ZRB019KH)
文摘The results of crystallographic analyses on 1：1 and 1：4 well-defined co-crystals formed between glycine anhydride and each of 4-hydroxybenzoic acid and 3,5-dihydroxybenzoic acid are described. Neutral molecules are connected via heteromeric O-H.-.O and N-H…O contacts leading to different packing arrangements of supramolecular chains. On the basis of the molec- ular structures of glycine anhydride and carboxylic acid vips, the hydrogen bonds are arranged to give centrosymmetric synthons V and VII which are noteworthy for their robustness. Hydrogen-bond interactions between glycine anhydride and aromatic acid provide sufficient driving force to direct molecular recognition and crystal packing. Utilization of the orientation of functional groups of the building blocks, the acidity, and weak interactions provides a route for the creation of novel supra- molecular architectures in the crystal lattice. Both two co-crystals contain the expected hydrogen-bonded motifs, and there has been no proton transfer from either of the two carboxylic acids to the aza compound moiety. This demonstrates that glycine anhydride is very capable of affecting the construction of binary co-crystals in a predictable and rationale manner. It is noted that synthons Ⅷ and IX are fairly large, but the real challenge in crystal engineering is to find a big enough synthon that occurs often enough. Thermal stability of these compounds has been investigated by thermogravimetric analysis （TGA） of mass loss.
基金supported by the National Natural Science Foundation of China(21971073,22001075,22231002)the Natural Science Foundation of Guangdong Province(2019A1515011468)+2 种基金the Discipline Construction Project of Guangdong Medical University(4SG23231G,4SG23249G)the Ordinary University Characteristic Innovation Project of Guangdong Province(2022KTSCX047)the Key-Area Research and Development Program of Guangdong Province(2020B010188001)。
文摘Carbon dioxide reduction, as a sustainable and versatile strategy for the access of chemical fuels, has attracted increasing attention and enormous efforts have been devoted to it in recent years. However, employing carbon dioxide as double synthons via bimolecular reduction remains challenging. Here, by leveraging the bimolecular reduction of carbon dioxide to carbonyl and methyl respectively, we describe a Pd-catalyzed trifunctionalization of alkynes with aryl iodide for the first time and showcase its advantages on the formation of various β-diketones and their application in the constructing of heterocyclic compounds with important biological activity, including pyrimidine, oxazole, pyrazole.
基金support from the Natural Science Foundation of Henan Province(No.222300420084)the Application Research Plan of Key Scientific Research Projects in Colleges and Universities of Henan Province(No.22A150056)is gratefully acknowledged.
文摘The first diastereodivergent formal[4+1]cycloaddition reactions of azoalkenes with p-quinone methides(pQMs)have been accomplished.The reported reaction occurred via a domino oxa-1,4-addition/1,6-addition process,allowing the use of common azoalkenes as C1 synthons.A broad range of 2,3-dihydrobenzofurans was smoothly prepared in good yields and with reversible diastereoselectivities.The steric hindrance and hydrogenbonding interaction were proposed to account for the two different modes of diastereo-control.The projected reaction features the employment of azoalkene as carbene-like C1 synthon,mild conditions,broad substrate scope and tunable diastereoselectivity.
基金supported by the Natural Science Foundation of Hubei Province(No.2017CFB355)the State Undergraduate Innovative Training Program(No.201610517012)
文摘The synthesis and aggregation behavior of two glycoluril derivatives were descrybed.The crystal of compound 1 belongs to the triclinic system,space group ■,with a=8.946（1）,b=13.445（2）,c=20.361（3）?,α=89.517（3）,β=84.405（3）,γ=86.325（3）°,Z=2,V=2432.1（6）?3,Dc=1.293 g·cm-3,C48H34N6O6·2DMSO,Mr=947.07,F（000）=992,μ=0.170 mm-1,the final R=0.1606 and wR=0.2410 for 4382 observed reflections（Ⅰ>2σ（Ⅰ））.The crystal of compound 2belongs to the monoclinic system,space group P21/c,with a=9.500（3）,b=24.522（8）,c=17.997（6）?,Z=2,V=4054（2）?3,Dc=1.296 g·cm-3,C48H34N6O6,Mr=790.81,F（000）=1648,μ=0.087mm-1,the final R=0.2146 and wR=0.2535 for 2878 observed reflections（Ⅰ>2σ（Ⅰ））.Unlike the highly conserved R22（8）hydrogen-bonding amide···amide homosynthon,the structural analysis indicated that compound 1 selected the C（20）hydrogen-bonding motif and 2 selected the R22（34）hydrogen-bonding motif,which revealed the competition from remote solvent molecule and the interference of the molecular hydrocarbon core in crystal packing.The supramolecular structure revealed molecule 1 is further linked into a one-dimensional chain and 2 into a two-dimensional interwoven plane by N–H···N hydrogen bonds.
基金supported by the National Natural Science Foundation of China(No.22072049)National Key Research and Development Project(No.2022YFE0124100)+2 种基金Major Special Projects of Science and Technology of Ordos(No.2022EEDSKJZDZX003)Program for HUST Academic Frontier Youth Team(No.2019QYTD06)is also acknowledgedChen is also grateful for the financial support from China Scholarship Council(CSC).
文摘Diversity-oriented synthesis is a powerful and interesting synthetic tool for the rapid construction of structurally complex and privileged scaffolds from readily accessible starting materials.To date,diversity-oriented synthesis mostly relies on the employment of versatile reagents.Versatile reagents can be regulated as controllable and flexible building blocks for multipurpose utilizations.Over the past decade,a variety of multifunctional reagents have been developed.However,most versatile reagents usually need multi-step synthesis,thus restricting their wide application to a large extent.In terms of the practicalities and universalities,we prefer to pay more attention to the utilization of simple and practical versatile reagents with multiple reactivities,mainly including atropaldehyde acetals,aryl methyl ketones,vinylene carbonate,vinyl azides,aryldiazonium salts,rongalite,halodifluoromethyl compounds.Most importantly,these versatile reagents can also play different roles simultaneously in the same reaction,in which their different reactivities are converged into the final target products.Such strategy can not only offer more possibilities for the synthesis of several active pharmaceutical ingredients,but also minimize the occurrence of some side reactions by lessening the varieties of materials.Also,a perspective is given at the end of this review.
文摘From natural tartaric acid, (R)-2-benzyloxy-3-(2-tetrahydropyranyloxy) propanol 3 was designed and synthesized, and (R)-2-benzyloxy-3-(4-methoxybenzyloxy) propanol 7 was prepared in a new method. They can be used as chiral synthons of lysophosphatidic acid and other compounds with asymmetric propanetriol backbone.
基金financial support from the National Nature Science Foundation of China(Nos.81760625,81660576 and81560563)Projects of Guizhou Province(Nos.[2016]5623,JG[2016]06,[2019]1402,[2017]5609 and[2018]5781)。
文摘A quinine-derived thiourea-catalyzed inter-/intramolecular Michael cycloaddition of chromoneoxindole/benzofuranone synthons with 3-substituted methylenebenzofuranones has been established,which constructed enantiomerically pure bispiro[benzofuran-oxindole/benzofuran-chromanone]s bearing five consecutive stereocenters including two spiro quaternary carton centers in good yields(up to 93%) with high diastereoselectivities(up to>20:1 dr) and good enantioselectivities(up to>99% ee).Moreover,this is the first example of bifunctional chromone-benzofuranone synthon directed organocatalytic tandem reaction,and also the first example of the bispiro[benzofuran-oxindole] and bispirobenzofuranone,potentially useful in medicinal chemistry.
基金financially supported by the 863 Program(No.2015AA020941)the National Natural Science Foundation of China(Nos.21474003 and 91427304)+1 种基金National Science Foundation of USA(Nos.DMR-0906898 and DMR-1408872)the Joint-Hope Education Foundation.W.B.Z.acknowledges support from the National"1000 Plan(Youth)"of China
文摘This essay discusses some preliminary thoughts on the development of a rational and modular approach for molecular design in soft matter engineering and proposes ideas of structural and functional synthons for advanced functional materials. It echoes the Materials Genome Initiative by practicing a tentative retro-functional analysis （RFA） scheme. The importance of hierarchical structures in transferring and amplifying molecular functions into macroscopic properties is recognized and emphasized. According to the role of molecular segments in final materials, there are two types of building blocks： structural synthon and functional synthon. Guided by a specific structure for a desired function, these synthons can be modularly combined in various ways to construct molecular scaffolds. Detailed molecular structures are then deduced, designed and synthesized precisely and modularly. While the assembled structure and property may deviate from the original design, the study may allow further refinement of the molecular design toward the target function, The strategy has been used in the development of soft fullerene materials and other giant molecules. There are a few aspects that are not yet well addressed： （1） function and structure are not fully decoupled and （2） the assembled hierarchical structures are sensitive to secondary interactions and molecular geometries across different length scales. Nevertheless, the RFA approach provides a starting point and an alternative thinking pathway by provoking creativity with considerations from both chemistry and physics. This is particularly useful for engineering soft matters with supramolecular lattice formation, as in giant molecules, where the synthons are relatively independent of each other.
基金Financial support from the National Natural Science Foundation of China(NSFC, Nos. 21761021 and 21571094)Natural Science Foundation of Jiangxi Province(No. 20171BAB203002)Sci & Tech Project of Education Department of Jiangxi Province(No. 60007)
文摘A metal-free cross coupling between common CH2Cl2 and carboxylic acids has been achieved with K2CO3 as the sole additive. This simple protocol is a convenient and cost-effective route to synthesize methylene diesters from a wide scope of carboxylic acids substrates with good functional group tolerance. Several gram-scale reactions have been performed to evaluate the effectiveness and practicality of this protocol.
基金supported by the Beijing Natural Science Foundation(No.7222261)CAMS Innovation Fund for Medical Sciences(Nos.2022-I2M-01-015 and 2022-I2M-JB-010)+1 种基金Key R&D Program of Shan Dong Province(No.2019JZZY020909)Chinese Pharmacopoeia Commission Drug Standard Promoting Fund(No.2022Y01)。
文摘The virtual cocrystal screening approach based on molecular electrostatic potential surface(MEPS)maps is a fast and feasible computational method to estimate the probability of cocrystal formation by calculating the difference in the interaction site pairing energies of monomers and that of their assemblies prior to experimental screening.In this paper,we report 12 cocrystal forms of temozolomide with mono-,di-,and trihydroxy benzoic acids,namely,3-hydroxy-,2,4-dihydroxy-,2,5-dihydroxy-,2,6-dihydroxy-,3,4-dihydroxy-,and 3,4,5-trihydroxy-benzoic acids,as well as benzoic acid,as pharmaceutical coformers for the first time.10 single crystals out of the 12 cocrystal forms were obtained and unequivocally determined by single-crystal X-ray diffraction,which clarified spatial arrangements,molecular conformations,and supramolecular synthons.MEPS further gains some insights into the sites of hydrogen bonding interactions for exploring combination patterns in these assemblies.Modulated stability of TMZ was successfully achieved by cocrystallization with these acids.
基金The financial support from the National Key Research and Development Program of China(No.2020YFA0710200)National Natural Science Foundation of China(No.22171090)+1 种基金the Shanghai Science and Technology Innovation Action Plan(No.20JC1416900)the Fundamental Research Funds for the Central Universities is highly appreciated。
文摘Carbon dioxide(CO_(2))is an attractive C1 building block in chemical synthesis due to its abundance,availability and sustainability.However,the low reactivity and high stability generally limits its transformations under mild conditions to value added chemicals.Recent advances in flow chemistry provide effective means for the chemical transformation of CO_(2),and many new methods and techniques that fully utilized the advantages of continuous flow platforms for the chemical fixation of CO_(2)have been realized.In view of the rapid development and the urgent need for continuous transformation of CO_(2),herein we wish to present an update of the recent advances in this research area.
文摘A C/D ring synthon of vitamin D is readily obtained from cholesteryl acetate via oxidation, elimination of acetoxy group and Norrish type II photochemical reaction.
基金partial financial support from the Ministry of Science and Technology of China(No.2016YFE0132600)Zhengzhou University。
文摘A selective ring-opening [3+2] cyclization reaction of benzo[d]isoxazoles with 2-bromo-propanamides has been developed.The azaoxyallyl cation intermediates are employed as C^O 3-atom synthon to build oxa-heterocycles via the selectivity of suitable cyclization partners.This transformation provides rapid access to highly functionalized 2-hydroxyaryl-oxazolines under mild conditions and excellent regioselectivity.
基金supported by the Natural Science Foundation of Anhui Province Education Department(No.KJ2014A141,No.KJ2015A243,No.KJ2016A862)
文摘The construction of an unprecedented intertwined spiral solvent channel is driven by weak C–Cl…O and C–H…N interactions based on extraordinary parallel spirals which were structured from supramolecular synthon macrocycle 1（C44H44N4O4） with a propargylamine backbone. The product is characterized by ^1H NMR, ^13C NMR, IR and HRMS, and further confirmed by single-crystal X-ray diffraction. It crystallizes in the monoclinic system, space group C2/c, with a = 28.922（3）, b = 8.5069（9）, c = 21.687（2）A^°, β = 130.6320（10）°, V = 4049.4（7） A^°3 and Z = 8. A total of 11874 reflections were collected, of which 4942 were independent（Rint = 0.0590） and 2937 were observed with I 〉 2σ（I）. The final full-matrix least-squares refinement gave R（I 〉 2s（I）） = 0.069 and w R = 0.167, S = 1.05,（Δρ）max = 0.20 and（Δρ）min =-0.22 e·A^1-3. The fluorescence of the product is discussed.
文摘An efficient synthesis of functionalized 6-decalone 16, starting from a dienolate anion 3a via a tandem Michael reaction, is described. 16 could be used as a potential intermediate for synthesis of drimane related sesquiterpenes.
基金supported by the National Natural Science Foundation of China(20701023 & 20971076)the Natural Science Foundation of Shandong Province,China(BS2010NJ004 & 2009ZRB019KH)
文摘Benzotriazole,N,N'-dimethylpiperazine and N-methylpiperazine were applied to crystallize with 5-sulfosalicylic acid(5-H2SSA),affording three new binary molecular cocrystals [(C6H6N3+).(C7H5O6S-)].H2O(1),[(C6H16N22+)1/2.(C7H5O6S-)].H2O(2) and [(C5H14N22+).(C7H5O6S-)2].3H2O(3) under general conditions.Proton-transferring occurs from acid to nitrogen of N-donor compounds in all compounds 1,2 and 3.Analysis of the hydrogen-bonding synthons and their effects on crystal packing were also presented in the context of crystal engineering and host-vip chemistry.In compound 1,1-D infinite chains are extended to a 2-D layered architecture via strong O-H...O hydrogen bonds and then to a 3-D network by N-H...O interactions.Compound 2 and 3 both have the 1-D chain which is formed by O-H...O bonds and weak C-H...O hydrogen bonds.A common intramolecular S(6) [synthon I] ring is formed by the hydroxyl with the carboxyl group in all three compounds.
