Novel ambiphilic dichlorocarbenoid equivalent in alkene cyclopropanation and carbonyl olefination.

The Ti−Mg−dichloromethylene complexes derived from the oxidative addition of CCl4 to the Mg−TiCl4 bimetallic species serve as a novel class of ambiphilic dichlorocarbenoid equivalents. Not only is Ti−Mg−dichlorocarbenoid highly selective but also it seems highly reactive in both alkene cyclopropanations and carbonyl dichloromethylenations.