The palladium-catalyzed late-stage aroylation of 4-methyl-1,5-diaryl-lH-pyrazole-3-carboxylates has been developed via direct and exclusive mono-Csp^2-H bond activation with broad substrate scope and good functional g...The palladium-catalyzed late-stage aroylation of 4-methyl-1,5-diaryl-lH-pyrazole-3-carboxylates has been developed via direct and exclusive mono-Csp^2-H bond activation with broad substrate scope and good functional group tolerance. A dual-core dimeric palladacycle is confirmed by X-ray single crystal crystallography, and probably serves as an active species in the catalytic cycle.展开更多
An interesting regioselectivity is observed when the mixture of potassium crotyltrifluoroborate (1a) and aroyl chlorides having electron-deficient and electron-rich groups is microwaved in the presence of palladium-ca...An interesting regioselectivity is observed when the mixture of potassium crotyltrifluoroborate (1a) and aroyl chlorides having electron-deficient and electron-rich groups is microwaved in the presence of palladium-catalyst. In the case of electron withdrawing group with phenyl ring of aroyl chlorides, isomerized α,β-unsaturated compound 3 is the product whereas electron donating group with phenyl ring of aroyl chlorides furnishes α-adduct 4. Similar aroylation reaction is also established for potassium allyltrifluoroborate (1b). In this case, regioselectivity is unaffected with changing electron-rich or electron-deficient groups in phenyl ring of the aroyl chlorides. Reactions proceed with, essentially in same rate, affording the corresponding aryl propenyl ketones (crotonophenones) 5 in good to high yields.展开更多
The deprotonative functionalization of toluenes,for their weak acidity,generally needs strong bases,thus leading to the requirement of harsh conditions and the generation of by-products.Direct nucleophilic acyl substi...The deprotonative functionalization of toluenes,for their weak acidity,generally needs strong bases,thus leading to the requirement of harsh conditions and the generation of by-products.Direct nucleophilic acyl substitution reaction of amides with organometallic reagents could provide an ideal solution for ketone synthesis.However,the inert amides and highly reactive organometallic reagents bring great challenges for an efficient and selective synthetic approach.Herein,we reported an lithium diisopropylamide(LDA)-promoted benzylic aroylation of toluenes with unactivated tertiary benzamides,providing a direct and efficient synthesis of various aryl benzyl ketones.This process features a kinetic deprotonative functionalization of toluenes with a readily available base LDA.Mechanism studies revealed that the directed ortho-lithiation of the tertiary benzamide with LDA promoted the benzylic kinetic deprotonation of toluene and triggered the nucleophilic acyl substitution reaction with the amide.展开更多
Cholesterol is a sterol with a four-membered ring structure and a single hydroxyl group attached to one of the rings. It is the active, raw form of cholesterol. Cholesteryl Ester is the inactive form in which choleste...Cholesterol is a sterol with a four-membered ring structure and a single hydroxyl group attached to one of the rings. It is the active, raw form of cholesterol. Cholesteryl Ester is the inactive form in which cholesterol is esterified to be transported to target organs. The newly developed process of making bulky esters from unprecedented tertiary alcohols is applied to synthesize cholesterol esters successfully. Although cholesterol is a secondary alcohol, it is a very bulky and interesting compound due to its immense application. Usually, specific enzymes catalyze cholesterol to cholesterol ester. This project aims to develop a cross-coupling chemistry process to synthesize cholesterol esters and see the broader application of those new cholesterol esters in chemical biology. The mixture of cholesterol, sodium tert-butoxide, aroyl chloride, the catalyst PdCl2 (dtbpf) complex, and the solvent 1,4-dioxane, when microwaved at 100˚C for 2 hours, works well for the formation of cross-coupling cholesterol ester products in good to high yields.展开更多
The direct aroylation of ArCOPdCl with potassium aryltrifluoroborates establishes a new cross-coupling synthetic tool for the synthesis of various fluorine substituted benzophenones. The new microwave irradiated proce...The direct aroylation of ArCOPdCl with potassium aryltrifluoroborates establishes a new cross-coupling synthetic tool for the synthesis of various fluorine substituted benzophenones. The new microwave irradiated process is very efficient and produce high yield benzophenone products within minutes.展开更多
Microwave-assisted synthesis of new 2-arylpyrimido[4′,5′：4,5]thiazolo[3,2-α]benzimidazol-4（3H）-ones from 3-aminothia- zolo[3,2-α]benzimidazol-2-earboxamide and aroyl halides in solvent-free condition is describ...Microwave-assisted synthesis of new 2-arylpyrimido[4′,5′：4,5]thiazolo[3,2-α]benzimidazol-4（3H）-ones from 3-aminothia- zolo[3,2-α]benzimidazol-2-earboxamide and aroyl halides in solvent-free condition is described. In comparison with classical conditions the reactions are faster and the yields are higher under microwave irradiation.展开更多
The title compound 1-（4-bromobenzoyl）-3-[5-（E）-styryl-1,3,4-thiadiazol-2-yl]urea （C18H13BrN4O2S, Mr = 429.29） has been synthesized by the reaction of 2-amino-5-styryl-1,3,4-thiadiazole with 4-bromobenzoyl isocya...The title compound 1-（4-bromobenzoyl）-3-[5-（E）-styryl-1,3,4-thiadiazol-2-yl]urea （C18H13BrN4O2S, Mr = 429.29） has been synthesized by the reaction of 2-amino-5-styryl-1,3,4-thiadiazole with 4-bromobenzoyl isocyanate, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P1^- with a = 7.0111（9）, b = 10.6587（14）, c = 12.5228（16）A^°,α = 79.724（2）, β= 78.275（2）, γ= 72.604（2）°, V = 867.43（19）A^°3, Z = 2, Oc = 1.644 g/cm^3, μ = 2.511 mm^-1, F（000） =432, R = 0.0448 and wR = 0.1198 for 2382 observed reflections with 1 〉 2σ（I）. X-ray analysis reveals that the molecules, in which every one is nearly planar, are linked by paired N-H…O hydrogen bonds into R22（8） dimers and stacked through π-π interactions.展开更多
AlCl3-mediated cleavage of ethereal methyl–oxygen bond in aroylated 2,7-dimethoxynaphthalene compounds proceeds chemospecifically and regioselectively. The ethereal bond at the β(2)-position of 1-monoaroylated 2,7-d...AlCl3-mediated cleavage of ethereal methyl–oxygen bond in aroylated 2,7-dimethoxynaphthalene compounds proceeds chemospecifically and regioselectively. The ethereal bond at the β(2)-position of 1-monoaroylated 2,7-dimethoxynaphthalene is cleaved readily and predominantly against the β(7)-position, whereas scission of β-ethereal bonds of 1,8-diaroylated 2,7-dimethoxynaphthalene hardly undergoes like the non-aroylated mother frame compound of 2,7-dimethoxynaphthalene.展开更多
New solid complexes derived from the reaction of aroyl hydrazones, 2-hydroxy-1-naphthaldehyde benzene sulphonyl hydrazone (HNB), and 2-hydroxy-1-naphthaldehyde p-toluene sulphonyl hydrazone (HNT), with Co<sup>2+...New solid complexes derived from the reaction of aroyl hydrazones, 2-hydroxy-1-naphthaldehyde benzene sulphonyl hydrazone (HNB), and 2-hydroxy-1-naphthaldehyde p-toluene sulphonyl hydrazone (HNT), with Co<sup>2+</sup>, Ni<sup>2+</sup>, and Cu<sup>2+</sup> salts have been isolated and characterized using elemental analyses, spectral (UV-vis., IR), molar conductivity and magnetic measurements. The modes of bonding as well as the stereochemistry of the isolated solid complexes were discussed. The results suggested that both HNB and HNT coordinated with the metal ions in a bidentate manner forming a polymeric chain in the case of HNB while monocular complexes were formed in the case of HNT. The amounts of solvent in the solid complexes were determined by TGA measurements. Also, spectral studies of HNT with Co<sup>2+</sup> and Fe<sup>3+</sup> ions in solution were carried and the ratio of complexes was determined by continuous variation, molar ratio, and slope ratio methods. Moreover, the results suggest the formation of 1:1 (M:L) for Co<sup>2+</sup> ions while three species with ratios of 1:1, 1:2, and 2:1 (M:L) have been observed in the case of Ni<sup>2+</sup> and Cu<sup>2+</sup>. Finally, conductance titration of HNB and HNT with Co<sup>2+</sup> ion elucidates the formation of two species with ratios 1:1 and 1:2 (M:L) in the case of the Co<sup>2+</sup>-HNB while 1:1 (M:L) belongs to the Co<sup>2+</sup>-HNT system.展开更多
Carbon-based solid acid catalyst has been applied to catalyzing the synthesis of 4（3H）-quinazolinones from the cyclization reaction of 2-aminobenzamide with aroyl chlorides. The results showed that the catalyst was ...Carbon-based solid acid catalyst has been applied to catalyzing the synthesis of 4（3H）-quinazolinones from the cyclization reaction of 2-aminobenzamide with aroyl chlorides. The results showed that the catalyst was very efficient with the average yield over 85%. This carbon material with strong protonic acid sites as heterogeneous cata- lyst has some advantages such as high activity, strikingly simple work-up procedure, non-pollution, and reusability, which will contribute to the green process greatly.展开更多
An unprecedented palladium/copper cocatalyzed coupling reaction of indoles with simple aroyl hydrazides has been developed under aerobic conditions. A range of aroyl hydrazides underwent palladium/copper cocatalyzed o...An unprecedented palladium/copper cocatalyzed coupling reaction of indoles with simple aroyl hydrazides has been developed under aerobic conditions. A range of aroyl hydrazides underwent palladium/copper cocatalyzed oxidative arylation with indoles open to air in a 1：1 mixture of dimethyl sulfoxide and nitromethane to give structurally diverse 2-arylindoles or 3-arylindoles in moderate to good yields. The reaction well tolerates a wide variety of functional groups such as alkoxy, halo, ester.展开更多
基金the National Natural Science Foundation of China(Nos. 21476074 and 21676088)for financial support
文摘The palladium-catalyzed late-stage aroylation of 4-methyl-1,5-diaryl-lH-pyrazole-3-carboxylates has been developed via direct and exclusive mono-Csp^2-H bond activation with broad substrate scope and good functional group tolerance. A dual-core dimeric palladacycle is confirmed by X-ray single crystal crystallography, and probably serves as an active species in the catalytic cycle.
文摘An interesting regioselectivity is observed when the mixture of potassium crotyltrifluoroborate (1a) and aroyl chlorides having electron-deficient and electron-rich groups is microwaved in the presence of palladium-catalyst. In the case of electron withdrawing group with phenyl ring of aroyl chlorides, isomerized α,β-unsaturated compound 3 is the product whereas electron donating group with phenyl ring of aroyl chlorides furnishes α-adduct 4. Similar aroylation reaction is also established for potassium allyltrifluoroborate (1b). In this case, regioselectivity is unaffected with changing electron-rich or electron-deficient groups in phenyl ring of the aroyl chlorides. Reactions proceed with, essentially in same rate, affording the corresponding aryl propenyl ketones (crotonophenones) 5 in good to high yields.
基金This work was supported by the Natural Science Foundation of Tianjin(19JCYBJC20100).
文摘The deprotonative functionalization of toluenes,for their weak acidity,generally needs strong bases,thus leading to the requirement of harsh conditions and the generation of by-products.Direct nucleophilic acyl substitution reaction of amides with organometallic reagents could provide an ideal solution for ketone synthesis.However,the inert amides and highly reactive organometallic reagents bring great challenges for an efficient and selective synthetic approach.Herein,we reported an lithium diisopropylamide(LDA)-promoted benzylic aroylation of toluenes with unactivated tertiary benzamides,providing a direct and efficient synthesis of various aryl benzyl ketones.This process features a kinetic deprotonative functionalization of toluenes with a readily available base LDA.Mechanism studies revealed that the directed ortho-lithiation of the tertiary benzamide with LDA promoted the benzylic kinetic deprotonation of toluene and triggered the nucleophilic acyl substitution reaction with the amide.
文摘Cholesterol is a sterol with a four-membered ring structure and a single hydroxyl group attached to one of the rings. It is the active, raw form of cholesterol. Cholesteryl Ester is the inactive form in which cholesterol is esterified to be transported to target organs. The newly developed process of making bulky esters from unprecedented tertiary alcohols is applied to synthesize cholesterol esters successfully. Although cholesterol is a secondary alcohol, it is a very bulky and interesting compound due to its immense application. Usually, specific enzymes catalyze cholesterol to cholesterol ester. This project aims to develop a cross-coupling chemistry process to synthesize cholesterol esters and see the broader application of those new cholesterol esters in chemical biology. The mixture of cholesterol, sodium tert-butoxide, aroyl chloride, the catalyst PdCl2 (dtbpf) complex, and the solvent 1,4-dioxane, when microwaved at 100˚C for 2 hours, works well for the formation of cross-coupling cholesterol ester products in good to high yields.
文摘The direct aroylation of ArCOPdCl with potassium aryltrifluoroborates establishes a new cross-coupling synthetic tool for the synthesis of various fluorine substituted benzophenones. The new microwave irradiated process is very efficient and produce high yield benzophenone products within minutes.
文摘Microwave-assisted synthesis of new 2-arylpyrimido[4′,5′：4,5]thiazolo[3,2-α]benzimidazol-4（3H）-ones from 3-aminothia- zolo[3,2-α]benzimidazol-2-earboxamide and aroyl halides in solvent-free condition is described. In comparison with classical conditions the reactions are faster and the yields are higher under microwave irradiation.
基金This work was supported by the National Natural Science Foundation of China (No. 20072009) and the Project for Distinguished Young Scholars from Hubei Provincial Department of Education (No.Q200529003).
文摘The title compound 1-（4-bromobenzoyl）-3-[5-（E）-styryl-1,3,4-thiadiazol-2-yl]urea （C18H13BrN4O2S, Mr = 429.29） has been synthesized by the reaction of 2-amino-5-styryl-1,3,4-thiadiazole with 4-bromobenzoyl isocyanate, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P1^- with a = 7.0111（9）, b = 10.6587（14）, c = 12.5228（16）A^°,α = 79.724（2）, β= 78.275（2）, γ= 72.604（2）°, V = 867.43（19）A^°3, Z = 2, Oc = 1.644 g/cm^3, μ = 2.511 mm^-1, F（000） =432, R = 0.0448 and wR = 0.1198 for 2382 observed reflections with 1 〉 2σ（I）. X-ray analysis reveals that the molecules, in which every one is nearly planar, are linked by paired N-H…O hydrogen bonds into R22（8） dimers and stacked through π-π interactions.
文摘AlCl3-mediated cleavage of ethereal methyl–oxygen bond in aroylated 2,7-dimethoxynaphthalene compounds proceeds chemospecifically and regioselectively. The ethereal bond at the β(2)-position of 1-monoaroylated 2,7-dimethoxynaphthalene is cleaved readily and predominantly against the β(7)-position, whereas scission of β-ethereal bonds of 1,8-diaroylated 2,7-dimethoxynaphthalene hardly undergoes like the non-aroylated mother frame compound of 2,7-dimethoxynaphthalene.
文摘New solid complexes derived from the reaction of aroyl hydrazones, 2-hydroxy-1-naphthaldehyde benzene sulphonyl hydrazone (HNB), and 2-hydroxy-1-naphthaldehyde p-toluene sulphonyl hydrazone (HNT), with Co<sup>2+</sup>, Ni<sup>2+</sup>, and Cu<sup>2+</sup> salts have been isolated and characterized using elemental analyses, spectral (UV-vis., IR), molar conductivity and magnetic measurements. The modes of bonding as well as the stereochemistry of the isolated solid complexes were discussed. The results suggested that both HNB and HNT coordinated with the metal ions in a bidentate manner forming a polymeric chain in the case of HNB while monocular complexes were formed in the case of HNT. The amounts of solvent in the solid complexes were determined by TGA measurements. Also, spectral studies of HNT with Co<sup>2+</sup> and Fe<sup>3+</sup> ions in solution were carried and the ratio of complexes was determined by continuous variation, molar ratio, and slope ratio methods. Moreover, the results suggest the formation of 1:1 (M:L) for Co<sup>2+</sup> ions while three species with ratios of 1:1, 1:2, and 2:1 (M:L) have been observed in the case of Ni<sup>2+</sup> and Cu<sup>2+</sup>. Finally, conductance titration of HNB and HNT with Co<sup>2+</sup> ion elucidates the formation of two species with ratios 1:1 and 1:2 (M:L) in the case of the Co<sup>2+</sup>-HNB while 1:1 (M:L) belongs to the Co<sup>2+</sup>-HNT system.
文摘Carbon-based solid acid catalyst has been applied to catalyzing the synthesis of 4（3H）-quinazolinones from the cyclization reaction of 2-aminobenzamide with aroyl chlorides. The results showed that the catalyst was very efficient with the average yield over 85%. This carbon material with strong protonic acid sites as heterogeneous cata- lyst has some advantages such as high activity, strikingly simple work-up procedure, non-pollution, and reusability, which will contribute to the green process greatly.
文摘An unprecedented palladium/copper cocatalyzed coupling reaction of indoles with simple aroyl hydrazides has been developed under aerobic conditions. A range of aroyl hydrazides underwent palladium/copper cocatalyzed oxidative arylation with indoles open to air in a 1：1 mixture of dimethyl sulfoxide and nitromethane to give structurally diverse 2-arylindoles or 3-arylindoles in moderate to good yields. The reaction well tolerates a wide variety of functional groups such as alkoxy, halo, ester.
