Reactions of bis(trimethylsilyl)bromomethyllithium and tris(trimethylsilyl)methyllithium. the synthesis of α-bromovinylsilanes
作者:Dietmar Seyferth、James L. Lefferts、Robert L. Lambert
DOI:10.1016/s0022-328x(00)91814-x
日期:1977.12
Bis(trimethylsilyl)bromomethyllithium, (Me3Si)2CBrLi, reacts with aldehydes to give α-bromovinyltrimethylsilanes, Me3SiCBrCHR (both isomers), but with alkyl ketones only proton abstraction from the enolic form of the ketone occurs. The reaction of this lithium reagent with benzophenone gives the oxirane, (Me3Si)2.α-Bromovinylsilanes of type Me3SiCBrCR2 can he prepared by reaction of R2CCBrLi (prepared
Novel cyclo-oligomerization of nickel carbenoids: a simple and efficient synthesis of radialenes
作者:Masahiko Iyoda、Akira Mizusuna、Hiroyuki Kurata、Masaji Oda
DOI:10.1039/c39890001690
日期:——
Novel cyclo-oligomerization of nickel methylenecarbenoids generated from 1,1-dihalogenoethenes with chemically activated nickel gives [3]-, [4]-, and [5]-radialenes directly under mild conditions.
A series of 1,1-dihaloalkenes were stepwise brominated using N-bromosuccinimide (NBS) under the catalysis of benzoyl peroxide (BPO) to afford the corresponding bromination products in moderate to high yields.
butyl-lithium at –100 °C, followed by treatment with a copper(I) complex produces the ate-type complex of the corresponding copper carbenoid, which cyclizes upon warming to afford decamethyl[5]radialene together with octamethyl[4]radialene; the structure of decamethyl[5]radialene has been established by X-ray analysis.