Ti/Mg-Mediated McMurry Coupling of Aryl Aldehydes and Imino Pinacol Coupling

Abstract

Significance: The authors describe a titanium isopropoxide/trimethylsilyl chloride/magnesium mediated McMurry coupling of aryl aldehydes to biaryl olefins at nearly room temperature. The same reagent also mediates the imino pinacol coupling of aryl aldimines to 1,2-diamines.Comment: By the addition of triethylamine, the amount of undesired 1,2-diol byproduct can be minimized. In contrast to other low-valent titanium-mediated reactions, this new method allows homogeneous reaction mixtures (except for the magnesium powder) instead of slurries of activated titanium.