High Throughput Sequence-controlled Oligosiloxane Synthesis

Matsumoto and Shimada et al. have reported the high throughput oligosiloxane synthesis from some silanes as starting materials. According to their report, the coupling of trimethylsilyl acetate with dialkylsilanes in the presence of chlorobis(cyclooctene)iridium(I) dimer catalyst gives the desired disilyl acetals (1) in good yield. In this reaction, a rearrangement of the siloxy group of 1 proceeds in the presence of the tris(pentafluorophenyl)borane (2) catalyst and corresponding disiloxanes (3) are given effectively. 2 acts as a Si-H bond activator which enables the oligosiloxane synthesis to proceed with the coupling of third component organosilanes after the first two silane-component coupling, thus giving the related oligosilanes with five-silicon-atoms. Generally, sequential-controlled siloxane syntheses have been difficult. This synthetic method, however, is expected to be used for new oligosiloxane syntheses.