Reactivity and diastereoselectivity of Michael additions of amines to achiral alpha,beta-unsaturated thioamides

Heterocyclic, aliphatic amines add to acyclic and cyclic alpha,beta -unsatu rated thioamides yielding beta -amino-functionalized derivatives. In the ca se of cyclic acceptors, the formation of both kinetic and thermodynamically controlled products is observed. Tailoring of cis or trans products is thu s possible. A mechanism for the addition to cyclic acceptors is proposed an d evidence presented to support it. Ease of addition is studied in relation to the structure of the acceptors. (C) 2001 Elsevier Science Ltd. All righ ts reserved.