Simultaneous Construction of Polymer Backbone and Side Chains by Three-Component Polycondensation. Synthesis of Polyethers with Cyano Side Chains from Dialdehydes, Alkylene Bis(trimethylsilyl) Ethers, and Cyanotrimethylsilane

Polyethers with cyano side chains were synthesized by the simultaneous acid-catalyzed reaction of dialdehydes ( 1 ), alkylene bis(trimethylsilyl) ethers ( 2 ), and cyanotrimethylsilane ( 4 ). The reactions of 1, 2, and 4 were carried out in the presence of 10 mol % of triphenylmethyl (trityl) perchlorate at ambient temperature by the addition of 4 into the reaction mixture of 1, 2, and trityl perchlorate to yield polyethers having cyano groups in the side chains. When 1 was added to the mixture of 2, 4, and trityl perchlorate, a low-molecular-weight oligomer was formed. The observed deference is attributed to the fact that 4 was more reactive than 2 toward 1, as shown in the model reactions using monofunctional analogues. This polyether synthesis is unusual in that it concurrently constructs both the polymer backbone and the functional side chains from three compounds.