The merging of transition metal catalysis with electrochemistry has become a powerful tool for organic synthesis because catalysts can govern the reactivity and selectivity.However,coupling catalysts with alkyl radica...The merging of transition metal catalysis with electrochemistry has become a powerful tool for organic synthesis because catalysts can govern the reactivity and selectivity.However,coupling catalysts with alkyl radical species generated by anodic oxidation remains challenging because of electrode passivation,dimerization,and overoxidation.In this study,we developed convergent paired electrolysis for the coupling of nickel catalysts with alkyl radicals derived from photoinduced ligand-to-metal charge-transfer of cyclic alcohols and iron catalysts,providing a practical method for site-specific and remote arylation of ketones.The synergistic use of photocatalysis with convergent paired electrolysis can provide alternative avenues for metal-catalyzed radical coupling reactions.展开更多
The first asymmetric synthesis of (+)-methyl cembra-1,3,7,11-tetraene-16-carboxynate, a naturally occurring cembrane-type macrocyclic diterpene isolated from Sinularia mayi, was achieved via general approach by employ...The first asymmetric synthesis of (+)-methyl cembra-1,3,7,11-tetraene-16-carboxynate, a naturally occurring cembrane-type macrocyclic diterpene isolated from Sinularia mayi, was achieved via general approach by employing an intramolecular McMurry coupling and Sharpless asymmetric epoxidation as the key steps from readily available starting materials. The synthesis presented here verifies that the absolute configuration of compound 1 was assumed as 15R.展开更多
A highly stereoselective synthesis of the side chain enantiomers of brassinolide and dolicholide through an aldol reaction of 2-(4-methoxy benzyloxyl) propionylaldehyde (5) with the anion of 1-(tert-butyldimethylsilox...A highly stereoselective synthesis of the side chain enantiomers of brassinolide and dolicholide through an aldol reaction of 2-(4-methoxy benzyloxyl) propionylaldehyde (5) with the anion of 1-(tert-butyldimethylsiloxy)-3-methyl-2-butanone (6) is described.展开更多
Organic electrosynthesis has been widely used as an environmentally conscious alternative to conventional methods for redox reactions because it utilizes electric current as a traceless redox agent instead of chemical...Organic electrosynthesis has been widely used as an environmentally conscious alternative to conventional methods for redox reactions because it utilizes electric current as a traceless redox agent instead of chemical redox agents. Indirect electrolysis employing a redox catalyst has received tremendous attention, since it provides various advantages compared to direct electrolysis. With indirect electrolysis, overpotential of electron transfer can be avoided, which is inherently milder, thus wide functional group tolerance can be achieved. Additionally, chemoselectivity, regioselectivity, and stereoselectivity can be tuned by the redox catalysts used in indirect electrolysis. Furthermore, electrode passivation can be avoided by preventing the formation of polymer films on the electrode surface. Common redox catalysts include N-oxyl radicals, hypervalent iodine species, halides, amines, benzoquinones(such as DDQ and tetrachlorobenzoquinone), and transition metals. In recent years, great progress has been made in the field of indirect organic electrosynthesis using transition metals as redox catalysts for reaction classes including C–H functionalization, radical cyclization, and cross-coupling of aryl halides-each owing to the diverse reactivity and accessible oxidation states of transition metals. Although various reviews of organic electrosynthesis are available, there is a lack of articles that focus on recent research progress in the area of indirect electrolysis using transition metals, which is the impetus for this review.展开更多
基金supported by the National Key R&D Program of China(2021YFA1500100)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0610000)+2 种基金the National Natural Science Foundation of China(21821002,22361142834,and 22101294)the S&TCSM of Shanghai(21ZR1476500)Natural Science Foundation of Ningbo(2023J035)。
文摘The merging of transition metal catalysis with electrochemistry has become a powerful tool for organic synthesis because catalysts can govern the reactivity and selectivity.However,coupling catalysts with alkyl radical species generated by anodic oxidation remains challenging because of electrode passivation,dimerization,and overoxidation.In this study,we developed convergent paired electrolysis for the coupling of nickel catalysts with alkyl radicals derived from photoinduced ligand-to-metal charge-transfer of cyclic alcohols and iron catalysts,providing a practical method for site-specific and remote arylation of ketones.The synergistic use of photocatalysis with convergent paired electrolysis can provide alternative avenues for metal-catalyzed radical coupling reactions.
基金This work was financially supported by the National Key R&D Program of China(No.2021YFA1500100)the NSF of China(Grants 21821002,21772222,and 91956112)the S&TCSM of Shanghai(Grants 20XD1425100 and 20JC1417100).
基金supported by the National Key R&D Program of China(2021YFA1500100)the National Natural Science Foundation of China(21821002,21772222,91956112,and 22101294)+1 种基金the Science and Technology Commission of Shanghai Municipality of Shanghai(18JC1415600 and 20JC1417100)Syngenta(UK).And it is also dedicated to professor Li-Xin Dai on the occasion of his 100th birthday.
文摘The first asymmetric synthesis of (+)-methyl cembra-1,3,7,11-tetraene-16-carboxynate, a naturally occurring cembrane-type macrocyclic diterpene isolated from Sinularia mayi, was achieved via general approach by employing an intramolecular McMurry coupling and Sharpless asymmetric epoxidation as the key steps from readily available starting materials. The synthesis presented here verifies that the absolute configuration of compound 1 was assumed as 15R.
基金Project supported by the National Natural Science Foundation of China(No.20072012)and the Special research Grant for Doctoral Sites in Chinese Universities(No.20010730001).
文摘A highly stereoselective synthesis of the side chain enantiomers of brassinolide and dolicholide through an aldol reaction of 2-(4-methoxy benzyloxyl) propionylaldehyde (5) with the anion of 1-(tert-butyldimethylsiloxy)-3-methyl-2-butanone (6) is described.
基金supported by the National Natural Science Foundation of China (21821002, 21772222, and 91956112)Chinese Academy of Sciences (XDB20000000)Science and Technology Commission of Shanghai Municipality (18JC1415600 and 20JC1417100)。
文摘Organic electrosynthesis has been widely used as an environmentally conscious alternative to conventional methods for redox reactions because it utilizes electric current as a traceless redox agent instead of chemical redox agents. Indirect electrolysis employing a redox catalyst has received tremendous attention, since it provides various advantages compared to direct electrolysis. With indirect electrolysis, overpotential of electron transfer can be avoided, which is inherently milder, thus wide functional group tolerance can be achieved. Additionally, chemoselectivity, regioselectivity, and stereoselectivity can be tuned by the redox catalysts used in indirect electrolysis. Furthermore, electrode passivation can be avoided by preventing the formation of polymer films on the electrode surface. Common redox catalysts include N-oxyl radicals, hypervalent iodine species, halides, amines, benzoquinones(such as DDQ and tetrachlorobenzoquinone), and transition metals. In recent years, great progress has been made in the field of indirect organic electrosynthesis using transition metals as redox catalysts for reaction classes including C–H functionalization, radical cyclization, and cross-coupling of aryl halides-each owing to the diverse reactivity and accessible oxidation states of transition metals. Although various reviews of organic electrosynthesis are available, there is a lack of articles that focus on recent research progress in the area of indirect electrolysis using transition metals, which is the impetus for this review.
基金Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0610000)the National Key R&D Program of China(No.2021YFA1500100)+2 种基金the National Natural Science Foundation of China(Nos.21821002,91956112,22101294)the Science and Technology Commission of Shanghai Municipality of Shanghai(Nos.21ZR1476500,20XD1425100)the Natural Science Foundation of Ningbo(No.2023J035)。
