Copper-Mediated Intramolecular Oxidative C?H/C?H Cross-Coupling of α?Oxo Ketene N,S?Acetals for Indole Synthesis

摘要

CuCl_2-mediated intramolecular C?H/C?H cross-dehydrogenative coupling (CDC) of thioalkyl-substituted α-acetyl or α-aroyl ketene N,S-acetals afforded 2-thioalkyl indoles. Tunable C?S bond transformations of the resultant indoles led to highly functionalized N-heterocyclic compounds. A β-thioalkyl is necessary to activate the N,S-acetal substrate and enable the CDC reaction to occur, and the relevant mechanism studies revealed that the CDC reaction follows a radical pathway.