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.
were successfully used in the Ni(CO)4 -induced carbonylation reactions of gem-dibromocyclopropanes. The nickel carbenoid and enolate complexes are considered to be involved as key intermediates. Protonation afforded the cyclopropanecarboxylic acid derivatives. The presence of an electrophile achieved another stereoselective carbon-carbon bond formation via the nickel enolate intermediate.
Halomethyl-Metal Compounds. II. The Preparation of gem-Dihalocyclopropanes by the Reaction of Phenyl(trihalomethyl)mercury Compounds with Olefins<sup>1</sup>
作者:Dietmar Seyferth、James M. Burlitch、Richard J. Minasz、Jeffrey Yick-Pui Mui、Harry D. Simmons、Arno J. H. Treiber、Susan R. Dowd
DOI:10.1021/ja00947a009
日期:1965.10
Preparation of tribromogermylcyclopropanes by insertion of dibromogermylene into the C−Br bonds of 1,1-dibromo-2-trimethylsilylcyclopropane
作者:V. V. Schcherbinin、K. V. Pavlov、I. P. Shvedov、O. S. Korneva、L. G. Menchikov、O. M. Nefedov
DOI:10.1007/bf02502957
日期:1997.9
Stereospecificity in the Gas Phase. Formation and Characterization of Configurationally Stable Cyclopropyl Anions
作者:Michael C. Baschky、Kent C. Peterson、Steven R. Kass
DOI:10.1021/ja00095a026
日期:1994.8
We report the gas-phase preparation of cis- and trans-beta-formylcyclopropyl anion (4c and 4t) via the room temperature fluorodesilylation of their corresponding trimethylsilyl derivatives. These homoenolates do not interconvert or undergo ring-opening isomerization at 25 degrees C, and can readily be differentiated with several chemical probes. The proton affinities of both 4c and 4t have been measured, and the results are compared to ab initio computations. Cyclization to a 2-bicyclobutoxide ion (8) has been considered, and although the process is calculated to have a small activation barrier, it is found to be thermodynamically unfavorable.