The carboxylation of alkynes with CO_(2) has attracted considerable interest due to the valorization of C1resources and atomic economy.Much effort focused on active metals(e.g.,Au,Ag,Cu),while the mechanistic role of ...The carboxylation of alkynes with CO_(2) has attracted considerable interest due to the valorization of C1resources and atomic economy.Much effort focused on active metals(e.g.,Au,Ag,Cu),while the mechanistic role of active supports,particularly the oxygen vacancy(O_(v)),in modulating C-H bond carboxylation remains unknown.Herein,ultra-small silver clusters and morphologically engineered CeO_(2) support(nanorods,nanocubes,and nano particles)were employed to construct Ag cluster/O_(v) synergistic catalyst,which exhibits variations in Oy concentration by an in situ auto-reduction method.The 0.197%Ag/CeO_(2)-NR catalyst exhibited a high reaction rate for the phenylacetylene carboxylation reaction and the maximal silver utilization efficiency.The characterization and DFT calculations demonstrated that vacancies enhanced CO_(2) adsorption via polarization-induced molecular bending and C-O bond elongation.Positively charged Ag clusters induced by metal-support interactions serve as deprotonation activation centers for alkynes.This synergistic interplay between dual active sites efficiently facilitates the C(sp)-H carboxylation with CO_(2).These findings offer critical insights for the rational selection of active supports in designing efficient C-H carboxylation catalysts.展开更多
Alkynyl selenides were prepared under very mild conditions by reacting terminal alkynes with respective diorganic diselenides in the presence of potassium t-butoxide. The advantages of this protocol include the use of...Alkynyl selenides were prepared under very mild conditions by reacting terminal alkynes with respective diorganic diselenides in the presence of potassium t-butoxide. The advantages of this protocol include the use of readily available substrates and reagent and good yield of the products.展开更多
A highly efficient and regio-/stereoselective method of hydrosilylating terminal alkynes was developed using Pt(DVDS)-tri(t-butyl) phosphine catalyst system at room temperature.Trans-products or alpha-products were ob...A highly efficient and regio-/stereoselective method of hydrosilylating terminal alkynes was developed using Pt(DVDS)-tri(t-butyl) phosphine catalyst system at room temperature.Trans-products or alpha-products were obtained almost exclusively depending on the alkynes and silanes employed.展开更多
Bottom-up approach to constructing low-dimensional nanostructures on surfaces with terminal alkynes has drawn great interest because of its potential applications in fabricating advanced functional nanomaterials. The ...Bottom-up approach to constructing low-dimensional nanostructures on surfaces with terminal alkynes has drawn great interest because of its potential applications in fabricating advanced functional nanomaterials. The diversity of the achieved products manifests rich chemistry of terminal alkynes and hence careful linking strategies and proper controlling methodologies are required for selective preparations of high-quality target nanoarchitectures. This review summarizes various on-surface linking strategies for terminal alkynes, including non-bonding interactions as well as organometallic and covalent bonds, and presents examples to show effective control of surface assemblies and reactions of terminal alkynes by variations of the precursor structures, substrates and activation modes. Systematic studies of the on-surface linkage of terminal alkynes may help efficient and predictable preparations of surface nanomaterials and further understanding of surface chemistry.展开更多
A novel catalytic reaction has been developed for the nucleophilic addition of terminal alkynes toα,β‐unsaturated‐γ‐lactams via a cyclic N‐acyliminium ion intermediate. This simple reaction pro‐ceeds rapidly u...A novel catalytic reaction has been developed for the nucleophilic addition of terminal alkynes toα,β‐unsaturated‐γ‐lactams via a cyclic N‐acyliminium ion intermediate. This simple reaction pro‐ceeds rapidly under mild conditions, and provided a practical approach for the synthesis of a wide range of 5‐alkynyl‐2‐pyrrolidinones in moderate to good yields （45%–76%）.展开更多
The hydroarylation reaction of terminal alkynes with arylboronic acids catalyzed by low(400 ppm) loadings of palladium has been developed. The reaction is broad in scope and high-yielding, even on multigram scale. It ...The hydroarylation reaction of terminal alkynes with arylboronic acids catalyzed by low(400 ppm) loadings of palladium has been developed. The reaction is broad in scope and high-yielding, even on multigram scale. It is suitable for the synthesis of alkenes labeled with deuterium, and for the late-stage modification of bioactive molecules.展开更多
The stereospecific carbocupration of terminal alkynes via higher order cuprates to give 1,1'-disubstituted olefins with 99% configuration purity is described. Its synthetic utility as a general method for the prep...The stereospecific carbocupration of terminal alkynes via higher order cuprates to give 1,1'-disubstituted olefins with 99% configuration purity is described. Its synthetic utility as a general method for the preparation of substituted olefins is further illustrated by the direct synthesis of (±)-ipsenol and (E)-β-farnesene with highly geometric purity of the carbon-carbon double bond.展开更多
Organosilicon compounds are widely valuable,making the efficient synthesis of alkenyl silanes an important research goal.A novel catalytic system based on a tridentate anionic ligand and cobalt has been developed for ...Organosilicon compounds are widely valuable,making the efficient synthesis of alkenyl silanes an important research goal.A novel catalytic system based on a tridentate anionic ligand and cobalt has been developed for the Markovnikov-selective hydrosilylation of terminal aliphatic alkynes,followed by isomerization of the disubstituted alkenyl silane intermediate,providing efficient access to trisubstituted alkenyl silanes.This system is also highly effective for the Markovnikov hydrosilylation of aryl alkynes.The protocol demonstrates broad functional group tolerance and can be performed on a gram scale.The catalyst achieves a turnover number(TON)of up to 1760 in hydrosilylation reaction.Mechanistic studies suggest that the anionic ligand,upon coordination,forms a dual functional catalyst with cobalt,which is key to enabling this transformation.It is proposed that a cobalt-hydride species selectively catalyzes both the hydrosilylation of terminal alkynes and the subsequent isomerization of the disubstituted alkenyl silane.This work provides an efficient and selective synthetic method using an earth-abundant metal catalyst for alkene synthesis via hydrosilylation and isomerization.展开更多
Alkyne metathesis is a cornerstone reaction in synthetic chemistry.However,metathesis of terminal alkynes remains a rare accomplishment,both catalytically and stoichiometrically.To overcome this challenge,we explored ...Alkyne metathesis is a cornerstone reaction in synthetic chemistry.However,metathesis of terminal alkynes remains a rare accomplishment,both catalytically and stoichiometrically.To overcome this challenge,we explored reactions of non-d^(0)carbyne complexes with terminal alkynes.展开更多
By the strategy of replacing the H_(2)O ligands in the“paddle wheel”shaped copper dimer Cu_(2)(OAc)_(4)(H_(2)O)_(2)with polyoxometalate(POM)[H_(2)W_(12)O_(40)]_(6)−{W_(12)O_(40)}pro-ligands,a novel nano porous 2D ne...By the strategy of replacing the H_(2)O ligands in the“paddle wheel”shaped copper dimer Cu_(2)(OAc)_(4)(H_(2)O)_(2)with polyoxometalate(POM)[H_(2)W_(12)O_(40)]_(6)−{W_(12)O_(40)}pro-ligands,a novel nano porous 2D network{[Cu_(2)(OAc)_(4)]_(2)(W_(12)O_(40))}_(n)was obtained.The POM-copper centered redox reactions and stability of the compound were studied by cyclic voltammetry.Furthermore,the compound was found to be a superefficient homogeneous catalyst(almost 100%conversion)in homo-coupling of terminal alkynes compared with its components and physical mixture under mild conditions with low amounts.The in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy(DRIFTS)results clearly show the changes of alkyne substances in the catalytic process and the X-ray photoelectron spectroscopy(XPS)results reveal the electron transfer from{W_(12)O_(40)}to Cu(Ⅱ)to promote the C-H activation step during the homo-coupling of terminal alkynes.The synergistic Cu(Ⅱ)-POM catalytic mechanism was proposed.展开更多
A(POCOP)-supported palladium complex was used to catalyse the dehydrogenative borylation of terminal alkynes to form alkynylboronates.Competing hydrogenation reactions could be mitigated through the use of additives s...A(POCOP)-supported palladium complex was used to catalyse the dehydrogenative borylation of terminal alkynes to form alkynylboronates.Competing hydrogenation reactions could be mitigated through the use of additives such as phosphines or elemental mercury.展开更多
The manganese(II)complex[Mn(SiNSi)Cl_(2)](SiNSi=2,6-[EtNSi(NtBu)_(2)CPh]_(2)C_(5)H_(3)N)is an efficient catalyst for the chemoselective C(sp)–H borylation of terminal alkynes.Aliphatic and aromatic alkynes with diffe...The manganese(II)complex[Mn(SiNSi)Cl_(2)](SiNSi=2,6-[EtNSi(NtBu)_(2)CPh]_(2)C_(5)H_(3)N)is an efficient catalyst for the chemoselective C(sp)–H borylation of terminal alkynes.Aliphatic and aromatic alkynes with different substituents have been efficiently borylated.Mechanistic studies indicate that the precatalyst enters the cycle by reaction with HBPin(Pin=pinacolate),which plays a key role in enabling a high chemoselective process.展开更多
Readily prepared chiral bis(imidazoline)NCN pincer iridium(III)complexes have been developed as the new and highly stereoselective catalysts for the direct asymmetric addition of terminal alkynes to trifluoropyruvates...Readily prepared chiral bis(imidazoline)NCN pincer iridium(III)complexes have been developed as the new and highly stereoselective catalysts for the direct asymmetric addition of terminal alkynes to trifluoropyruvates.With a catalyst loading of 5 mol%,a variety of optically activeα-trifluoromethylated tertiary propargylic alcohols were thus produced in good yields with high enantioselectivity(27 examples,74%–96%ee).Both enantiomers of the catalysis products were obtained by using enantiomeric Ir(III)catalysts.In addition,gram scale synthesis of the product and its transformation to a potentially very useful 2H-1,2,3-triazole compound were accomplished.Control experiments suggested that the alkynylide Ir(III)intermediates were involved in the reactions.展开更多
Transition metal-catalyzed hydrostannylation of alkynes is an atom-economic way towards valuableα-vinylstannanes.However,directing-group-free examples for the construction ofα-adducts are rare and mostly undergo the...Transition metal-catalyzed hydrostannylation of alkynes is an atom-economic way towards valuableα-vinylstannanes.However,directing-group-free examples for the construction ofα-adducts are rare and mostly undergo the M-Sn species insertion process.Here,we report an efficient cobalt-catalyzed highlyα-selective hydrostannylation of terminal alkynes via M-H species,using readily available Bu3Sn H and easily accessible as well as bench-stable ligand.The robust catalytic system,bearing good functional group tolerance and operational simplicity,provides theα-vinylstannanes in moderate to excellent yields with≥97:3 rr averagely.The efficiency of the reaction is investigated with turnover number(TON)up to 10,000 and turnover frequency(TOF)up to 144,000 h^(-1),respectively.The synthetic utility of theα-vinylstannanes is proved by further derivatizations towards the 1,1-disubstituted alkenes via Kosugi-Migita-Stille cross-coupling,conjugated alkene,α-vinyliodine,α-vinylazide,and allyl alcohol.Several control experiments,deuterium-labeling experiment and density functional theory(DFT)calculations are conducted to reveal the preliminary mechanism.展开更多
Iron-mediated sp-sp3 C-C bond formation through the cross dehydrogenative coupling(CDC) of terminal alkynes with benzylic ethers or alkanes has been developed.The inexpensive iron salt is used as the catalyst to make ...Iron-mediated sp-sp3 C-C bond formation through the cross dehydrogenative coupling(CDC) of terminal alkynes with benzylic ethers or alkanes has been developed.The inexpensive iron salt is used as the catalyst to make this transformation environmentally benign.Iron-mediated sp-sp3 C-C bond formation through the cross dehydrogenative coupling(CDC) of terminal alkynes with benzylic ethers or alkanes has been developed.The inexpensive iron salt is used as the catalyst to make this transformation environmentally benign.展开更多
The cross-dimerization of terminal alkynes is the most straightforward and attractive approach to differently substituted 1,3-enynes,which are vital structural motifs in natural products,biologically active compounds,...The cross-dimerization of terminal alkynes is the most straightforward and attractive approach to differently substituted 1,3-enynes,which are vital structural motifs in natural products,biologically active compounds,and organic functional materials,etc.However,due to the inherent issues of the stereo-,regio-,and chemoselectivity,the strategy is less explored and remains problematic in substrate scope,selectivity,and screening of catalytic system,etc.Herein,a specific cross-dimerization of terminal alkynes is developed under Pd/TMEDA catalysis,which produces a series of gem-1,3-enynes(58 examples)in totally moderate to high yields with outstanding functional group tolerance.A cyclopalladium compound might be the key imtermediate,which performs anti-addition-carbometallation,and leads to the exclusive cross-selectivity.The unprecedented features of the reaction,such as anti-addition-carbometallation,easy control of selectivity,wide range of the donor alkynes,and very simple catalytic conditions,allow it not only a facile and functionally diverse synthesis of 1,3-enynes,but also a substantial progress for the textbook reaction.展开更多
The efficient utilization of visible light catalysts for organic reactions necessitates not only the effective separation of photogenerated electrons and holes to participate in the reaction,but also their ability to ...The efficient utilization of visible light catalysts for organic reactions necessitates not only the effective separation of photogenerated electrons and holes to participate in the reaction,but also their ability to form key intermediates with reactant molecules.The present study successfully synthesized a crusiform-like mesoporous structure of nitrogen-doped carbon-coated Cu_(2)O/Cu(Cu_(2)O/Cu/N-C)with a Cu_(2)O/dual electron acceptor interface using etched HKUST-1 as the precursor.A series of theoretical and experimental studies have demonstrated that the Cu_(2)O/Cu/N-C interface in the photocatalytic homo-coupling of terminal alkynes not only effectively enhances the separation of photogenerated electron−hole pairs,but also facilitates the formation of the key intermediate[Cu_(2)O/Cu/N-C]-phenylacetylide and promotes the rearrangement of its internal charges.As a result,the homo-coupling reaction can be effectively facilitated.The primary reason for the functional role of Cu_(2)O/Cu/N-C interface lies in the downward bending of energy band from Cu_(2)O to N-doped C layers,induced by the different work functions of Cu_(2)O,Cu and N-doped C layers.Consequently,Cu_(2)O/Cu/N-C photocatalysts demonstrate exceptional photocatalytic activity in the homo-coupling reaction of terminal alkynes under blue-light irradiation and air atmosphere.The present study presents a novel research methodology for the development of highly efficient visible light catalysts to facilitate organic reactions in future applications.展开更多
Asymmetric ring-expansion reactions of silacyclobutanes(SCBs)with alkynes have evolved as one of the powerful protocols for the construction of silicon-stereogenic compounds.However,the achievement of highly enantiose...Asymmetric ring-expansion reactions of silacyclobutanes(SCBs)with alkynes have evolved as one of the powerful protocols for the construction of silicon-stereogenic compounds.However,the achievement of highly enantioselective annulation of SCBs with terminal alkynes remains a challenge.Herein,we report a rhodium-catalyzed asymmetric annulation reaction of SCBs with terminal alkynes,which relies on the newly identified chiral sulfinamide phosphine ligand Ming-Phos.This catalytic system exhibits unique effects under mild conditions,leading to the direct synthesis of structurally diverse chiral silacycles in moderate to good yields with high enantioselectivities(up to 95%ee).展开更多
Mercurous chloride catalyzed Mannich condensation of terminal alkynes with secondary amines and aldehydes has been developed. The reaction generated β-aminoalkynes in good yields.
Reaction of perfluoroalkyl iodides with a series of alkynes under sulfinatodehalogenation condition gave a mixture of E/Z adducts very readily in high yield, thus constituted a mild, convenient and effective new metho...Reaction of perfluoroalkyl iodides with a series of alkynes under sulfinatodehalogenation condition gave a mixture of E/Z adducts very readily in high yield, thus constituted a mild, convenient and effective new method for the addition of perfluoroalkyl iodides to alkynes. Under the same con- dition, in the presence of 1-hexyne perfluoroalkyl bromide and 1,1,1-trichlorotrifluoroethane reacted only to give sulfinates as the major products. A radical mechanism was proposed for the addition reaction.展开更多
基金financially supported by the National Natural Science Foundation of China(22102194)the Science and Technology Plan of Gansu Province(24JRRA067,23ZDFA016)the Youth Innovation Promotion Association of CAS(2022427)。
文摘The carboxylation of alkynes with CO_(2) has attracted considerable interest due to the valorization of C1resources and atomic economy.Much effort focused on active metals(e.g.,Au,Ag,Cu),while the mechanistic role of active supports,particularly the oxygen vacancy(O_(v)),in modulating C-H bond carboxylation remains unknown.Herein,ultra-small silver clusters and morphologically engineered CeO_(2) support(nanorods,nanocubes,and nano particles)were employed to construct Ag cluster/O_(v) synergistic catalyst,which exhibits variations in Oy concentration by an in situ auto-reduction method.The 0.197%Ag/CeO_(2)-NR catalyst exhibited a high reaction rate for the phenylacetylene carboxylation reaction and the maximal silver utilization efficiency.The characterization and DFT calculations demonstrated that vacancies enhanced CO_(2) adsorption via polarization-induced molecular bending and C-O bond elongation.Positively charged Ag clusters induced by metal-support interactions serve as deprotonation activation centers for alkynes.This synergistic interplay between dual active sites efficiently facilitates the C(sp)-H carboxylation with CO_(2).These findings offer critical insights for the rational selection of active supports in designing efficient C-H carboxylation catalysts.
基金the K.N.Toosi University of Technology Research Council for financial assistance
文摘Alkynyl selenides were prepared under very mild conditions by reacting terminal alkynes with respective diorganic diselenides in the presence of potassium t-butoxide. The advantages of this protocol include the use of readily available substrates and reagent and good yield of the products.
文摘A highly efficient and regio-/stereoselective method of hydrosilylating terminal alkynes was developed using Pt(DVDS)-tri(t-butyl) phosphine catalyst system at room temperature.Trans-products or alpha-products were obtained almost exclusively depending on the alkynes and silanes employed.
基金jointly supported by National Natural Science Foundation of China (NSFC) (Nos. 91527303, 21333001)
文摘Bottom-up approach to constructing low-dimensional nanostructures on surfaces with terminal alkynes has drawn great interest because of its potential applications in fabricating advanced functional nanomaterials. The diversity of the achieved products manifests rich chemistry of terminal alkynes and hence careful linking strategies and proper controlling methodologies are required for selective preparations of high-quality target nanoarchitectures. This review summarizes various on-surface linking strategies for terminal alkynes, including non-bonding interactions as well as organometallic and covalent bonds, and presents examples to show effective control of surface assemblies and reactions of terminal alkynes by variations of the precursor structures, substrates and activation modes. Systematic studies of the on-surface linkage of terminal alkynes may help efficient and predictable preparations of surface nanomaterials and further understanding of surface chemistry.
基金supported by the National Natural Science Foundation of China(21222203,21172226,21133011)
文摘A novel catalytic reaction has been developed for the nucleophilic addition of terminal alkynes toα,β‐unsaturated‐γ‐lactams via a cyclic N‐acyliminium ion intermediate. This simple reaction pro‐ceeds rapidly under mild conditions, and provided a practical approach for the synthesis of a wide range of 5‐alkynyl‐2‐pyrrolidinones in moderate to good yields （45%–76%）.
基金financial support from the National Natural Science Foundation of China (No. 21472033)the National Key R&D Program of China (No. 2018YFB1501604)the Fundamental Research Funds for the Central Universities (No. PA2020GDKC0021)。
文摘The hydroarylation reaction of terminal alkynes with arylboronic acids catalyzed by low(400 ppm) loadings of palladium has been developed. The reaction is broad in scope and high-yielding, even on multigram scale. It is suitable for the synthesis of alkenes labeled with deuterium, and for the late-stage modification of bioactive molecules.
基金Supported by the National Natural Science Foundation of China
文摘The stereospecific carbocupration of terminal alkynes via higher order cuprates to give 1,1'-disubstituted olefins with 99% configuration purity is described. Its synthetic utility as a general method for the preparation of substituted olefins is further illustrated by the direct synthesis of (±)-ipsenol and (E)-β-farnesene with highly geometric purity of the carbon-carbon double bond.
基金National Key Research and Development Program of China(2021YFA1500200)National Natural Science Foundation of China(NSFC)(22525109)+1 种基金Zhejiang Provincial Natural Science Foundation of China(LDQ24B020001)the Fundamental Research Funds for the Central Universities(226-2022-00224 and 226-2024-00003).
文摘Organosilicon compounds are widely valuable,making the efficient synthesis of alkenyl silanes an important research goal.A novel catalytic system based on a tridentate anionic ligand and cobalt has been developed for the Markovnikov-selective hydrosilylation of terminal aliphatic alkynes,followed by isomerization of the disubstituted alkenyl silane intermediate,providing efficient access to trisubstituted alkenyl silanes.This system is also highly effective for the Markovnikov hydrosilylation of aryl alkynes.The protocol demonstrates broad functional group tolerance and can be performed on a gram scale.The catalyst achieves a turnover number(TON)of up to 1760 in hydrosilylation reaction.Mechanistic studies suggest that the anionic ligand,upon coordination,forms a dual functional catalyst with cobalt,which is key to enabling this transformation.It is proposed that a cobalt-hydride species selectively catalyzes both the hydrosilylation of terminal alkynes and the subsequent isomerization of the disubstituted alkenyl silane.This work provides an efficient and selective synthetic method using an earth-abundant metal catalyst for alkene synthesis via hydrosilylation and isomerization.
基金supported by the Hong Kong Research Grants Council(Project No.:16308721,16302322,16305724,16300023).We acknowledge the support from HKUST Central High Performance Computing Cluster for providing computational resources.
文摘Alkyne metathesis is a cornerstone reaction in synthetic chemistry.However,metathesis of terminal alkynes remains a rare accomplishment,both catalytically and stoichiometrically.To overcome this challenge,we explored reactions of non-d^(0)carbyne complexes with terminal alkynes.
基金support of this work from the National Natural Science Foundation of China(NSFC 21801226)the Natural Science Foundation of Zhejiang Province(LY20B010002 and LQ22B010002)the Zhejiang Normal University Fund.
文摘By the strategy of replacing the H_(2)O ligands in the“paddle wheel”shaped copper dimer Cu_(2)(OAc)_(4)(H_(2)O)_(2)with polyoxometalate(POM)[H_(2)W_(12)O_(40)]_(6)−{W_(12)O_(40)}pro-ligands,a novel nano porous 2D network{[Cu_(2)(OAc)_(4)]_(2)(W_(12)O_(40))}_(n)was obtained.The POM-copper centered redox reactions and stability of the compound were studied by cyclic voltammetry.Furthermore,the compound was found to be a superefficient homogeneous catalyst(almost 100%conversion)in homo-coupling of terminal alkynes compared with its components and physical mixture under mild conditions with low amounts.The in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy(DRIFTS)results clearly show the changes of alkyne substances in the catalytic process and the X-ray photoelectron spectroscopy(XPS)results reveal the electron transfer from{W_(12)O_(40)}to Cu(Ⅱ)to promote the C-H activation step during the homo-coupling of terminal alkynes.The synergistic Cu(Ⅱ)-POM catalytic mechanism was proposed.
基金the US National Science Foundation(grant CHE-1300299 to O.V.O.)the Welch Foundation(grant A-1717 to O.V.O.).
文摘A(POCOP)-supported palladium complex was used to catalyse the dehydrogenative borylation of terminal alkynes to form alkynylboronates.Competing hydrogenation reactions could be mitigated through the use of additives such as phosphines or elemental mercury.
基金the ACS Petroleum Research Fund for a Doctoral New Investigator grant(PRF#66750-DNI3)UC Merced for start-up funds(SUP0000078).
文摘The manganese(II)complex[Mn(SiNSi)Cl_(2)](SiNSi=2,6-[EtNSi(NtBu)_(2)CPh]_(2)C_(5)H_(3)N)is an efficient catalyst for the chemoselective C(sp)–H borylation of terminal alkynes.Aliphatic and aromatic alkynes with different substituents have been efficiently borylated.Mechanistic studies indicate that the precatalyst enters the cycle by reaction with HBPin(Pin=pinacolate),which plays a key role in enabling a high chemoselective process.
基金supported by grants from the National Natural Science Foundation of China(Nos.21472176 and U1904212)the Natural Science Foundation of Henan Province(No.222300420294)the China Postdoctoral Science Foundation(No.2020M672260).
文摘Readily prepared chiral bis(imidazoline)NCN pincer iridium(III)complexes have been developed as the new and highly stereoselective catalysts for the direct asymmetric addition of terminal alkynes to trifluoropyruvates.With a catalyst loading of 5 mol%,a variety of optically activeα-trifluoromethylated tertiary propargylic alcohols were thus produced in good yields with high enantioselectivity(27 examples,74%–96%ee).Both enantiomers of the catalysis products were obtained by using enantiomeric Ir(III)catalysts.In addition,gram scale synthesis of the product and its transformation to a potentially very useful 2H-1,2,3-triazole compound were accomplished.Control experiments suggested that the alkynylide Ir(III)intermediates were involved in the reactions.
基金supported by the National Key R&D Program of China(2021YFF0701600,2021YFA1500200)the National Natural Science Foundation of China(22271249)+2 种基金the Zhejiang Provincial Natural Science Foundation of China(LR19B020001)the Fundamental Research Funds for the Central Universities(226-2022-00224,226-202400003)the Center of Chemistry for Frontier Technologies,Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province(PSFM 2021-05)。
文摘Transition metal-catalyzed hydrostannylation of alkynes is an atom-economic way towards valuableα-vinylstannanes.However,directing-group-free examples for the construction ofα-adducts are rare and mostly undergo the M-Sn species insertion process.Here,we report an efficient cobalt-catalyzed highlyα-selective hydrostannylation of terminal alkynes via M-H species,using readily available Bu3Sn H and easily accessible as well as bench-stable ligand.The robust catalytic system,bearing good functional group tolerance and operational simplicity,provides theα-vinylstannanes in moderate to excellent yields with≥97:3 rr averagely.The efficiency of the reaction is investigated with turnover number(TON)up to 10,000 and turnover frequency(TOF)up to 144,000 h^(-1),respectively.The synthetic utility of theα-vinylstannanes is proved by further derivatizations towards the 1,1-disubstituted alkenes via Kosugi-Migita-Stille cross-coupling,conjugated alkene,α-vinyliodine,α-vinylazide,and allyl alcohol.Several control experiments,deuterium-labeling experiment and density functional theory(DFT)calculations are conducted to reveal the preliminary mechanism.
基金supported by Peking University,the National Natural Science Foundation of China(20872003)National Basic Research Program of China(973 program)(2009CB825300)
文摘Iron-mediated sp-sp3 C-C bond formation through the cross dehydrogenative coupling(CDC) of terminal alkynes with benzylic ethers or alkanes has been developed.The inexpensive iron salt is used as the catalyst to make this transformation environmentally benign.Iron-mediated sp-sp3 C-C bond formation through the cross dehydrogenative coupling(CDC) of terminal alkynes with benzylic ethers or alkanes has been developed.The inexpensive iron salt is used as the catalyst to make this transformation environmentally benign.
基金supported by the National Natural Science Foundation of China(21878072,21706058,22102062,21725602)the Hunan Provincial Natural Science Foundation of China(2020JJ2011)the China Postdoctoral Science Foundation(2019M662774).
文摘The cross-dimerization of terminal alkynes is the most straightforward and attractive approach to differently substituted 1,3-enynes,which are vital structural motifs in natural products,biologically active compounds,and organic functional materials,etc.However,due to the inherent issues of the stereo-,regio-,and chemoselectivity,the strategy is less explored and remains problematic in substrate scope,selectivity,and screening of catalytic system,etc.Herein,a specific cross-dimerization of terminal alkynes is developed under Pd/TMEDA catalysis,which produces a series of gem-1,3-enynes(58 examples)in totally moderate to high yields with outstanding functional group tolerance.A cyclopalladium compound might be the key imtermediate,which performs anti-addition-carbometallation,and leads to the exclusive cross-selectivity.The unprecedented features of the reaction,such as anti-addition-carbometallation,easy control of selectivity,wide range of the donor alkynes,and very simple catalytic conditions,allow it not only a facile and functionally diverse synthesis of 1,3-enynes,but also a substantial progress for the textbook reaction.
基金supported by the Xuzhou Key Research and Development Program(Social Development)(No.KC23298)the National Natural Science Foundation of China(No.22271122)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20211549)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_2903).
文摘The efficient utilization of visible light catalysts for organic reactions necessitates not only the effective separation of photogenerated electrons and holes to participate in the reaction,but also their ability to form key intermediates with reactant molecules.The present study successfully synthesized a crusiform-like mesoporous structure of nitrogen-doped carbon-coated Cu_(2)O/Cu(Cu_(2)O/Cu/N-C)with a Cu_(2)O/dual electron acceptor interface using etched HKUST-1 as the precursor.A series of theoretical and experimental studies have demonstrated that the Cu_(2)O/Cu/N-C interface in the photocatalytic homo-coupling of terminal alkynes not only effectively enhances the separation of photogenerated electron−hole pairs,but also facilitates the formation of the key intermediate[Cu_(2)O/Cu/N-C]-phenylacetylide and promotes the rearrangement of its internal charges.As a result,the homo-coupling reaction can be effectively facilitated.The primary reason for the functional role of Cu_(2)O/Cu/N-C interface lies in the downward bending of energy band from Cu_(2)O to N-doped C layers,induced by the different work functions of Cu_(2)O,Cu and N-doped C layers.Consequently,Cu_(2)O/Cu/N-C photocatalysts demonstrate exceptional photocatalytic activity in the homo-coupling reaction of terminal alkynes under blue-light irradiation and air atmosphere.The present study presents a novel research methodology for the development of highly efficient visible light catalysts to facilitate organic reactions in future applications.
基金the funding support of the National Key R&D Program of China(No.2021YFF0701601)NSFC(Nos.22031004 and 21921003)+1 种基金Shanghai Municipal Education Commission(No.20212308)Science and Technology Commission of Shanghai Municipality(No.23ZR1404800).
文摘Asymmetric ring-expansion reactions of silacyclobutanes(SCBs)with alkynes have evolved as one of the powerful protocols for the construction of silicon-stereogenic compounds.However,the achievement of highly enantioselective annulation of SCBs with terminal alkynes remains a challenge.Herein,we report a rhodium-catalyzed asymmetric annulation reaction of SCBs with terminal alkynes,which relies on the newly identified chiral sulfinamide phosphine ligand Ming-Phos.This catalytic system exhibits unique effects under mild conditions,leading to the direct synthesis of structurally diverse chiral silacycles in moderate to good yields with high enantioselectivities(up to 95%ee).
基金Project supported by the National Natural Science Foundation of China （No. 20372024）, the Excellent Scientist Foundation of Anhui Province （No.04046080）, the Natural Science Foundation of the Education Department of Anhui Province （No. 2002kj254zd）, the Scientific Research Foundation for the Returned 0verseas Chinese Scholars, the Ministry of Education of China （No. 2002247）, the Excellent Young Teacher Program of the Ministry of Education of China （No. 2024） and the Key Project of Science and Technology of the Ministry of Education of China （No. 0204069）.
文摘Mercurous chloride catalyzed Mannich condensation of terminal alkynes with secondary amines and aldehydes has been developed. The reaction generated β-aminoalkynes in good yields.
文摘Reaction of perfluoroalkyl iodides with a series of alkynes under sulfinatodehalogenation condition gave a mixture of E/Z adducts very readily in high yield, thus constituted a mild, convenient and effective new method for the addition of perfluoroalkyl iodides to alkynes. Under the same con- dition, in the presence of 1-hexyne perfluoroalkyl bromide and 1,1,1-trichlorotrifluoroethane reacted only to give sulfinates as the major products. A radical mechanism was proposed for the addition reaction.
