Reactions of gem-dibromo compounds with trialkylmagnesate reagents to yield alkylated organomagnesium compounds.
The reaction of gem-dibromocyclopropanes 5 with nBu(3)MgLi affords butylated cyclopropylmagnesium species that can be trapped with various electrophiles. The reaction of dibromomethylsilanes 12 requires the addition of a catalytic amount of CuCN small middle dot2 LiCl for smooth migration of the alkyl groups. The resultant alpha-silylpentylmagnesium compounds 16 react with electrophiles, such as acyl chlorides or alpha,beta-unsaturated ketones to afford alpha- or gamma-silyl ketones, respectively. Treatment of dibromodisilylmethanes with Me(3)MgLi yields 1-bromo-1,1-disilylethanes 25 that can be converted into 1,1-disilylethenes 29 by dehydrobromination.
Inoue
Atsushi
A
Department of Material Chemistry Graduate School of Engineering, Kyoto University Kyoto 606-8501, Japan.
Kondo
Junichi
J
Shinokubo
Hiroshi
H
Oshima
Koichiro
K