Living synthesis of silicone polymers controlled by humidity

The preparation of hydrophobic silicone (co)polymers generally requires acid- or base-catalyzed equilibration reactions that, in addition to polymer formation, generate undesired low molecular weight cyclic species. We report that living polymerization of hydrosiloxanes, controlled by the presence of water (bulk water/humidity/wet solvent) and 0.01–0.5 mol% B(C6F5)3, arises from facile SiH hydrolysis to the silanol and, subsequently, a more …