An Efficient Protocol for Selective Silylation of Hydroxy Group Using N,O-Bis(tert-butyldimethylsilyl)acetamide and N,N-Dimethyl-4-aminopyridine N-Oxide

An efficient method for the silylation of alcohols was developed using N,O-bis(tert-butyldimethylsilyl)acetamide (BTBSA) and 3 mol % of N,N-dimethyl-4-aminopyridine N-oxide (DMAPO). Monosilylation of 1,2-diols was successfully achieved with high chemoselectivity. In addition, several control experiments revealed that a phenolic hydroxy group was silylated much faster than a primary alcohol in both an inter- and intramolecular manner. The reactivity toward silylation under these systems might stem from the pKa of the hydroxy group.