Nazarov reaction of trisubstituted dienones: mechanism involving Wagner-Meerwein shift
摘要:
The Nazarov reactions of trisubstituted alpha,alpha'-dienones were studied. Whereas alpha,beta-dimethyl-beta'-alkyl alpha,alpha'-dienones gave 2,3-dimethyl-4-alkyl-2-cyclopentenones when heated in concentrated sulfuric acid, the reaction of beta,beta-dimethyl-beta'-alkyl alpha,alpha'-dienones afforded 3,4-dimethyl-4-alkyl-2-cyclopentenones as the rearranged products. A mechanistic investigation using two deuterated dienones suggests that the Nazarov reactions of the latter dienones are accompanied by Wagner-Meerwein shifts to form the most stable carbocations.
Nazarov reaction of trisubstituted dienones: mechanism involving Wagner-Meerwein shift
摘要:
The Nazarov reactions of trisubstituted alpha,alpha'-dienones were studied. Whereas alpha,beta-dimethyl-beta'-alkyl alpha,alpha'-dienones gave 2,3-dimethyl-4-alkyl-2-cyclopentenones when heated in concentrated sulfuric acid, the reaction of beta,beta-dimethyl-beta'-alkyl alpha,alpha'-dienones afforded 3,4-dimethyl-4-alkyl-2-cyclopentenones as the rearranged products. A mechanistic investigation using two deuterated dienones suggests that the Nazarov reactions of the latter dienones are accompanied by Wagner-Meerwein shifts to form the most stable carbocations.
Palladium-catalyzed reactions of acylzirconocene chloride with organic halides
作者:Yuji Hanzawa、Nobuhito Tabuchi、Takeo Taguchi
DOI:10.1016/s0040-4039(98)01287-8
日期:1998.8
Palladium-catalyzed reactions of nonanoylzirconocene chloride 1 with aryl halide, acid halides, and allylic halides gave the acylated compounds through a nucleophilic attack of an “unmasked” acyl anion in fair to excellent yields. In an analogous way, allylic acetate gave an acyl substituted product through the reaction of 1.