New Nucleophilic Organocatalysts

Abstract

Acyl-transfer reactions have become commonplace in organic synthesis and organocatalysis of these reactions is becoming increasingly popular. 4-Dimethylaminopyridine has proven to be very useful in acylations; over the recent years chiral and more reactive analogs have received much attention. Interestingly, catalysis of acyl-transfers by diamines has also been shown to be effective. We present the synthesis of several DMAP analogs containing heteroatoms near the nucleophilic nitrogen. These analogs of DMAP vary from basic amidines, oxazolines, and amines, to alcohols, and fluoro-derivatives all of which may provide hydrogen bonding to the alcohol undergoing acyl-transfer. Since Steglich proposed the need for a base in the DMAP catalyzed acyl-transfer transition state no studies have been performed on the effect that nearby hydrogen bonding or nearby bases might have on catalytic efficiency and enantioselectivity of acylations. The variety of compounds synthesized should allow for studies into rate and selectivity enhancements in nucleophilic pyridine catalysis.