Thioisomünchnones versus Acrylamides via Copper-Catalyzed Reaction of Thioamides with Diazocarbonyl Compounds

Abstract

A novel carbenoid-mediated approach to thioisomünchnones was developed by intermolecular copper-catalyzed reactions of diazoacetamides with aromatic and heteroaromatic thioamides bearing a pyrrolidine moiety. The direction of the reaction can be switched toward 2-amino-2-heteroarylacrylamides by replacing the pyrrolidine with an aniline group or by the use of 2-cyano-2-diazoacetamides. The proposed mechanism and DFT calculations allowed us to rationalize the effect of substituents on the reaction direction. Effective methods were found for the synthesis of previously unknown both 2-heteroarylthioisomünchones and 2-heteroarylacrylamides, based on a wide scope of available reagents with a similar structure. Some of the synthesized thioisomünchnones exhibited multicolor fluorescence in the solid state and solutions.

Catalytic [4 + 1]-annulation of thioamides with carbenoid precursors

“…10 An important, albeit insufficiently developed method for the synthesis of heterocycles from the reaction of thioamides with carbenoid precursors is based on the generation of thiocarbonyl ylides. Their subsequent electrocyclizations were used in the effective construction of N- and N,S-heterocycles, 11 and were also important stages in the total synthesis of alkaloids supinidine, 12 chylenine, 13 and the antibiotic indolizomycin. 14…”