When copper (I) chloride was used as a catalyst in the reaction of silicon with phenol, a high selectivity for triphenoxysilane (HSi (OPh) 3)(94%) was obtained, the other product being tetraphenoxysilane (Si (OPh) 4). Addition of a small amount of propyl chloride to the feed for poisoning metallic copper enhanced the selectivity for HSi (OPh) 3 without affecting the rate of silicon consumption. This result indicates that HSi (OPh) 3 is an exclusive primary ...