We examined the puzzling mechanism for Cu-catalyzed meta-C-H arylation reaction of anilides by diaryliodonium salts through systematic theoretical analysis. The previously proposed anti-oxy-cupration mechanism featuri...We examined the puzzling mechanism for Cu-catalyzed meta-C-H arylation reaction of anilides by diaryliodonium salts through systematic theoretical analysis. The previously proposed anti-oxy-cupration mechanism featuring anti-1,2- or anti-1,4-addition of cuprate and oxygen to the phenyl ring generating a meta-cuprated intermediate was excluded due to the large activation barriers. Alternatively, a new amide-directed carbocupration mechanism was proposed which involves a critical rate- and regio-determining step of amide-directed addition of the Cu（III）-aryl bond across the phenyl C2=C3 double bond to form an orthocuprated, meta-arylated intermediate. This mechanism is kinetically the most favored among several possible mechanisms such as ortho-or para-cupration/migration mechanism, direct meta C-H bond cleavage mediated by Cu（III） or Cu（I）, and Cu（III）-catalyzed ortho-directed C-H bond activation mechanism this mechanism has been shown to Furthermore, the predicted regioselectivity based on favor the meta-arylation that is consistent with the experimental observations.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
基金This work was supported by the National Natural Science Foundation of China （No.20971058） and the Fundamental Research Funds for the Central Universities （No.JUSRPIII05）.
文摘We examined the puzzling mechanism for Cu-catalyzed meta-C-H arylation reaction of anilides by diaryliodonium salts through systematic theoretical analysis. The previously proposed anti-oxy-cupration mechanism featuring anti-1,2- or anti-1,4-addition of cuprate and oxygen to the phenyl ring generating a meta-cuprated intermediate was excluded due to the large activation barriers. Alternatively, a new amide-directed carbocupration mechanism was proposed which involves a critical rate- and regio-determining step of amide-directed addition of the Cu（III）-aryl bond across the phenyl C2=C3 double bond to form an orthocuprated, meta-arylated intermediate. This mechanism is kinetically the most favored among several possible mechanisms such as ortho-or para-cupration/migration mechanism, direct meta C-H bond cleavage mediated by Cu（III） or Cu（I）, and Cu（III）-catalyzed ortho-directed C-H bond activation mechanism this mechanism has been shown to Furthermore, the predicted regioselectivity based on favor the meta-arylation that is consistent with the experimental observations.
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.
