Attenuating Nucleophilicity of Titanocene Hydrides beyond Steric Effects en Route to Fatty Alcohols.

ABSTRACT

Here, we introduce a new class of titanocene catalysts for epoxide hydrosilylation that frustrates their hydridicity and thereby emphasizes their electron transfer reactivity. This unique attenuation of hydridicity is accomplished by introducing Lewis acidic silicon centers to the cyclopentadienyl ligands for an intramolecular coordination of the titanium bound hydride. The superiority of our rationally designed catalysts over classic titanocenes with alkyl substituted cyclopentadienyl ligands is demonstrated in the dramatically improved regioselectivity of the hydrosilylation of monosubstituted epoxides to primary alcohols.