Organocatalytic Living Ring-Opening Polymerization of Cyclic Carbosiloxanes
2006; American Chemical Society; Volume: 8; Issue: 21 Linguagem: Inglês
10.1021/ol0614166
ISSN1523-7060
AutoresBas G. G. Lohmeijer, Géraud Dubois, Frank A. Leibfarth, Russell C. Pratt, Fredrik Nederberg, Alshakim Nelson, Robert M. Waymouth, Charles G. Wade, James L. Hedrick,
Tópico(s)Organometallic Complex Synthesis and Catalysis
ResumoAn 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 pKb 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.
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