Base and Catalyst-Free Preparation of Silyl Ethers in the Choline Chloride/Urea Deep Eutectic Solvent (DES)

摘要

An efficient, fast, green, and mild procedure is reported for preparation of silyl ethers from aliphatic, benzylic, allylic, propargylic alcohols, phenols, naphthols, and some phenolic drugs. In this method, choline chloride/urea (ChCl/urea) deep eutectic solvent (DES) is used as an environmentally benign reaction medium. Silylation was accomplished by employing trimethylsilylchloride (TMSCl), triethylsilylchloride (TESCl), and t-butyldimethylsilylchloride (TDSCl) as the silylating agents. The significant advantages offered by this green protocol are high yields, operational simplicity, short reaction time, and also avoiding the use of any environmentally hazardous solvents, bases, and catalysts. This procedure can also be utilized in large scale silylation for industrial applications.[GRAPHICS].