Copper-Mediated Intramolecular Oxidative C–H/C–H Cross-Coupling of α-Oxo Ketene N,S-Acetals for Indole Synthesis
摘要:
CuCl2-mediated intramolecular C-H/C-H cross-dehydrogenative coupling (CDC) of thioalkyl-substituted a-acetyl or alpha-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 beta-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.
One-Pot Synthesis of 3-Acyl-2-(alkylsulfanyl)indoles and 2-(Alkylsulfanyl)indole-3-carboxylates from (2-Isocyanophenyl)methyl Ketones or (2-Isocyanophenyl)acetates
An efficient method has been developed for the preparation of 3-acyl-2-(alkylsulfanyl)indoles and ethyl 2-(alkylsulfanyl)indole-3-carboxylates under mild conditions. (2-Iso-cyanophenyl)methyl ketones and ethyl 2-(2-isocyanophenyl)acetates were converted into the corresponding isothiocyanates by treatment with sulfur in the presence of a catalytic amount of selenium. The isothiocyanates were then treated