Synthesis of 3-chloropiperidines by iodide-mediated electrolysis

Abstract

Herein we report the cyclization of N-pentenylamines and their corresponding hydrochloric acid salts to 3-chloropiperidines under ambient conditions in an electroorganic fashion with tetrabutylammoniumiodide (TBAI) as a redox catalyst. Through iodide mediated oxidation, the unsaturated amine can be cyclized in an environmentally benign way without the need for conventional oxidants in stoichiometric quantity. A wide variety of 3-chloropiperidine derivatives were obtained in yields of up to 95% in an undivided cell. Mechanistic investigation indicates a radical pathway for this transformation.