P(RNCH(2)CH(2))(3)N: Efficient Catalysts for Transesterifications, Acylations, and Deacylations

Extremely strong nonionic superbases of the type P(RNCH(2)CH(2))(3)N catalyze the transesterification of carboxylic acid esters with high selectivity and yields at 25 degrees C. These bases also catalyze the deacetylation of alcohols under mild conditions in quantitative yields. Using enol acetates as acylating agents, primary and secondary alcohols are efficiently protected as acetates through the action of these catalysts. Substituents such as epoxide, carbamate, acetal, oxazoline, nitro, and alkynyl functionalities are tolerated under the reaction conditions. N-Protected peptides undergo clean transesterification without significant racemization, making this methodology potentially very useful.