Stereoselective preparation of γ- and σ-sultams by thermal and high-pressure intramolecular Diels–Alder reaction of vinylsulfonamides

Abstract

A range of novel γ-and δ-sultams was prepared by intramolecular [4+2] cycloaddition of vinylsulfonamides with purely thermal activation and under high pressure. Using N-1-phenylethyl substituted vinylsulfonamides, enantiopure sultams were readily obtained, debenzylation of which provided the corresponding NH sultams in high yields in the case of δ-sultams.

Recent Developments in the Synthesis of Fused Sultams

“…Their continued interest in the synthesis of sultams by Diels–Alder reactions prompted Metz and co-workers to report , a stereoselective preparation of the tricyclic sultams 34.4 and 34.5 by thermal and high-pressure intramolecular Diels–Alder reaction of vinylsulfonamides 34.3 (Scheme ), and Lee and co-workers synthesized tricyclic sultams by Diels–Alder reaction as well …”

High pressure in organic chemistry on the way to miniaturization

“…87 A range of gand d-sultams have been prepared by intramolecular Diels-Alder reaction of vinylsulfonamides possessing an acyclic, furan, or carboxylic 1,3-diene moiety both thermally and under high pressure (13 kbar), with N-1-phenylethyl-substituted vinylsulfonamides giving enantiopure sultams. 88 The high pressure (8 kbar) Diels-Alder reactions of 5nitro[2.2]paracyclophanepyran-6-one with 1,3-butadienes gave the cycloadducts in a totally regioselective and anti-exo diastereoselective manner. 89 In the last few years, the combination of high pressure (12 kbar) and catalysis has been extensively used for the improvement of the selectivity of organic reactions.…”