A formal homo-Nazarov cyclization of enantioenriched donor–acceptor cyclopropanes and following transformations: asymmetric synthesis of multi-substituted dihydronaphthalenes
Multi-substituted trans-dihydronaphthalenes were obtained in high ee from a TiCl4-mediated cyclization of enantioenriched D–A cyclopropanes, followed by a triflation of OH.
gem-Dihalocyclopropane formation by iron/copper activation of tetrahalomethanes in the presence of nucleophilic olefins. Evidence for a carbene pathway
作者:Eric Léonel、Michael Lejaye、Sylvain Oudeyer、Jean Paul Paugam、Jean-Yves Nédélec
DOI:10.1016/j.tetlet.2004.01.124
日期:2004.3
The activation of CBr4 and CCl4 by a bimetallic iron/copper couple in acetonitrile is a new, inexpensive, nontoxic and efficient procedure for gem-dibromo- and gem-dichloromethylenation of nucleophilic alkenes. This new route to gem-dihalocyclopropanes involves dihalocarbene species.
Synthesis of 1,1-Bis(trimethylstannyl)cyclopropanes by the S<sub>RN</sub>1 Mechanism
作者:Javier F. Guastavino、Roberto A. Rossi
DOI:10.1021/om801104e
日期:2009.4.27
dichlorocarbene to alkenes, with Me3Sn− anions are reported. The process is described in terms of a photoinduced SRN1 substitution. The 1,1-bis(trimethylstannyl)cyclopropanes were obtained in good to excellent isolated yield (71−90%); 7,7-dichloro-2-oxa-bicyclo[4.1.0]heptane gave the 1,1-bis(trimethylstannyl) product in only 40% yield.