Organocatalytic Living Ring-Opening
Polymerization of Cyclic Carbosiloxanes

G. G. Lohmeijer, Bas; Dubois, Geraud; Leibfarth, Frank; Pratt, Russell C.; Nederberg, Fredrik; Nelson, Alshakim; Waymouth, Robert M.; Wade, Charles; Hedrick, James L.

doi:10.1021/ol0614166.s001

ol0614166_si_001.pdf (354.76 kB)

Organocatalytic Living Ring-Opening Polymerization of Cyclic Carbosiloxanes

journal contribution

posted on 2006-10-12, 00:00 authored by Bas G. G. Lohmeijer, Geraud Dubois, Frank Leibfarth, Russell C. Pratt, Fredrik Nederberg, Alshakim Nelson, Robert M. Waymouth, Charles Wade, James L. Hedrick

An organocatalytic route to narrowly dispersed poly(carbosiloxanes) of predictable molecular weight and end group fidelity is described. N-Heterocyclic carbenes (NHC) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) catalyze the ring opening of cyclic carbosiloxanes. The pK_b of the catalyst is important in preventing adverse transetherification reactions and obtaining well-defined polymers. Mechanistic studies indicate that hydrogen bonding to TBD or the NHC activates alcohols or silanols for ring-opening reactions.