Kinetics and mechanism of the reactions of primary amines with pyrylium cations
Abstract
The initial reaction of primary amines with pyrylium cations to give the ring-opened intermediate is fast for strongly basic amines and is base-catalysed for weak amines. Ring-closure of the intermediate to give the pyridinium derivative is subject to steric and electronic hindrance and is acid-catalysed. Solvent effects and the structure of the ring-opened intermediates are discussed.