Concerning the potential reversibility of carbometalation in alkoxide-directed Ti(Oi-Pr)4-mediated reductive cross-coupling of homoallylic alcohols with aromatic imines.

In an attempt to understand the nature of selectivity in Ti-mediated reductive cross-coupling between homoallylic alcohols and imines, we investigated whether thermodynamic equilibration of the presumed organometallic intermediate plays a role in selectivity. No evidence could be found for olefin exchange in preformed azatitanacyclopentanes--an observation that is consistent with a model based on kinetically controlled selective carbometalation.