Copper-Catalyzed Oxidative ipso-Cyclization of N-(p-Methoxyaryl)propiolamides with Disulfides and Water Leading to 3-(Arylthio)-1-azaspiro[4.5]deca-3,6,9-triene-2,8-diones

Abstract A new copper-catalyzed oxidative ipso-cyclization of N-(p-methoxyaryl)propiolamides with disulfides for the synthesis of 3-(arylthio)-1-azaspiro[4.5]deca-3,6,9-triene-2,8-diones has been developed. This method proceeds via sequential oxidative C–S bond formation, ipso-cyclization, and dearomatization and provides a new facile oxidative strategy to assemble the target products using an inexpensive catalytic system comprising copper(II) chloride and molecular oxygen.