ChemInform Abstract: Stereoselective Synthesis of 2,3‐Disubstituted Indoline, Pyrrolidine and Cyclic Ether‐Fused 1,2‐Dihydroquinoline Derivatives Using Alkyne Iminium Ion Cyclization of Vinylogous Carbamates: Switch of Regioselectivity Using an Internal Hydroxy Group as a Nucleophile.

Abstract

Internal Hydroxy Group as a Nucleophile. -The trimethylsilyl triflate-mediated cyclization of alkynes (I) and (IV) leads to trans-2,3-disubstituted indolines (II) and pyrrolidines (V), resp., whilst the cyclization of alcohols (VI) and (VIII) gives rise to isochromene-and pyran-fused dihydroquinolines (VII) and (IX), resp., as a result of an intramolecular hydroalkoxylation. -(GHARPURE*, S. J.; PRASATH, V.; KUMAR, V.; Chem. Commun. (Cambridge) 51 (2015) 71, 13623-13626, http://dx.doi.org/10.1039/C5CC05292K ; Dep. Chem., Indian Inst. Technol. Bombay, Mumbai 400 076, India; Eng.) -R. Staver 01-037