Poly(silyl ether)s (PSEs) exhibit high thermal stability, low glass transition temperatures, flame retardancy, and degradability, rendering them promising for elastomers, breathable films, and biocompatible coatings. However, their polymerization typically relies on metal-based catalysts under harsh conditions. Herein, we report a catalytic system: the frustrated Lewis pair (FLP) composed of a weak Lewis acid (planar arylborane) and a weak Lewis base (tri−n−butylphosphine oxide), enabling efficient conversion of 5-hydroxymethylfurfural (HMF) to linear PSEs under mild conditions. Mechanistic studies revealed that FLP activates Si−H bonds to form tetracoordinated phosphonium cation intermediates, which further react with hydroxymethyl or aldehyde groups of HMF for stepwise polymerization. This work provides a metal-free strategy for mild PSE synthesis.
Wang et al. (Thu,) studied this question.