Iron-copper cooperative catalysis is shown to be effective for an alkene-Grignard exchange reaction and alkylmagnesiation of alkynes. The Grignard exchange between terminal alkenes (RCH═CH(2)) and cyclopentylmagnesium bromide was catalyzed by FeCl(3) (2.5 mol %) and CuBr (5 mol %) in combination with PBu(3) (10 mol %) to give RCH(2)CH(2)MgBr in high yields. 1-Alkyl Grignardreagents add to alkynes in the
Preparation of alkenesvia a manganate-induced alkylation–elimination sequence was investigated. The reaction of 2-alkoxy-1,1-dibromoalkanes with trialkylmanganates afforded disubstituted or trisubstitutedalkenes. Treatment of 2-alkoxy-1,1,1-tribromoalkanes with trialkylmanganates provided trisubstituted or tetrasubstituted alkenes through bromine–metal exchange, transfer of two alkyl groups from
A remarkable steric effect in palladium-catalyzed Grignard coupling: regio- and stereoselective monoalkylation and -arylation of 1,1-dichloro-1-alkenes
作者:Akio Minato、Keizo Suzuki、Kohei Tamao
DOI:10.1021/ja00238a052
日期:1987.2
concern in transition-metalcomplex catalyzed carbon-carbon bond-forming reactions. As part of their continued studies on the palladium-phosphine complex catalyzed selective monoalkylation of organic polyhalides, they report here the first success in the regio- and stereoselective monoalkylation and -arylation of 1,1-dichloro-1-alkenes by Grignard or organozinc reagents in the presence of (PdCl/sub2/(dppb))
Alkyl- and aryllithium compoundswere found to add to alkynes having no heteroatoms in the presence of an iron or iron–copper catalyst to give various trisubstituted vinyllithium compounds.