Bismuth(iii) triflate promoted intramolecular hydroamination of unactivated alkenyl sulfonamides in the preparation of pyrrolidines

• DOI: 10.1039/c2ob07064b
• Publication Date: 2012-01-30T15:02:41Z
• Authors: František Mathia; Peter Szolcsányi
• Keywords: Hydroamination; Trifluoromethanesulfonate; Triflic acid; Lewis acid catalysis; Sulfonic acid

Bi(OTf)3·nH2O was found to be an efficient promoter of the cyclisative hydroamination unactivated alkenyl sulfonamides, giving rise N-protected 2-methyl pyrrolidines in good excellent yields (up 95%). Based on control experiments, a joint Lewis acid–Brønsted acid catalysis might operation, or triflic itself, generated situ by hydrolysis metal triflate, could true catalyst.