Titanocene-Catalyzed Hydrosilylation of Oxetanes─are Oxetanes the Better Epoxides?

We describe a titanocene-catalyzed hydrosilylation of oxetanes to yield primary alcohols in high yields, under robust conditions and with low catalyst loading, via ET from the catalyst to the oxetane and ensuing highly efficient HAT to the radical formed from the Ti–H bond. PhSiH3 or the inexpensive industrial waste product polymethylhydrosiloxane (PMHS) can be used as terminal reductant. The reactions are more selective and proceed under more efficient reaction conditions than titanocene-catalyzed epoxide hydrosilylations. The reasons for the high selectivity are outlined with the aid of DFT calculations and are compared with the reactions of epoxides.