Sequential and highly stereoselective intermolecular radical additions of 2,3-cis-disubstituted 1,1-dibromo- and 1-bromocyclopropanes to electron-deficient olefins
作者:Yoo Tanabe、Ken-ichi Wakimura、Yoshinori Nishii
DOI:10.1016/0040-4039(96)00156-6
日期:1996.3
Novel and sequential intermolecular radicaladditions of 2,3-cis-disubstituted 1,1-dibromo- and 1-bromocyclopropanes to electron-deficient olefins proceeded with high stereoselectivity, i.e., in an exo-face addition manner. This highly stereoselectiveaddition was also applied to an intramolecular cyclization.
Stereoselective sonochemical reductive silylation of geminal dibromocyclopropanes by bulk magnesium
作者:Jonathan Touster、Albert J. Fry
DOI:10.1016/s0040-4039(97)01453-6
日期:1997.9
trimethysilyl chloride and a bicyclic 1,1-dibromocyclopropane in the presence of bulk magnesium affords 1-trimethylsilyl-1-bromocyclopropanes in 72–93% yield. The sonochemical reactions proceed stereoselectively to afford as the major product the product in which the trimethylsilyl group is cis to the hydrogen atoms at the ring juncture.
Reaction of -dibromocyclopropanes with diphenylphosphide ion
作者:Gordon F. Meijs
DOI:10.1016/s0040-4039(00)98479-x
日期:1985.1
Diphenylphosphide ion undergoes a photostimulated reaction with 7,7-dibromobicyclo[4.1.0]heptane and 1,1-dibromo-2,2,3,3-tetramethylcyclopropane involving both ionic and radical steps to afford cyclopropyldiphenylphosphines resulting from substitution and reduction.
Stereoselective ultrasonically induced reductive monosilylation of geminal dibromonorcaranes. Steric effects
作者:Brian C Raimundo、Albert J Fry
DOI:10.1016/s0022-328x(99)00146-1
日期:1999.7
Sonochemical reductive silylation of 1-R-7,7-dibromonorcaranes (R = H, Me, Et, i-Pr) by magnesium produces in each case two 7-bromo-7-trialkylsilylnorcaranes (alkyl = methyl or ethyl). The major isomer is exo (the trialkylsilyl group is cis to the R substituent), but the stereoselectivity of silylation decreases as the alkyl group size at C-l increases, 1-Phenyl-7,7-dibromonorcarane produced a mixture of phenylcycloheptadienes and monobromonorcaranes. (C) 1999 Elsevier Science S.A. All rights reserved.