The Use of Tin(IV) Chloride for Mild and Selective Boc Deprotection on TFA Cleavable Rink-Amide MBHA Resin

Abstract

An efficient, straightforward and inexpensive method for selective Boc deprotection on Rink-amide MBHA resin using tin(IV) chloride in dichloromethane is presented. Preliminary results suggest that the low degree of cleavage from the resin accompanying the Boc deprotection may depend on steric hindrance associated with the resin. This method can be useful as a selective deprotection step in solid-phase syntheses of cyclic peptides and small molecules in which only a few Boc deprotection steps are required.