One-Pot Relay Gold(I) and Brønsted Acid Catalysis: Cyclopenta[b]annulation of Indoles via Hydroamination/Nazarov-Type Cyclization Cascade of Enynols
摘要:
An expedient relay gold(I) and Bronsted acid catalyzed hydroamination/Nazarov cyclization of 1-(2-aminophenyl)pent-4-en-2-ynols for the synthesis of various polyfunctionalized cyclopenta[b]indoles is described. The synthetic utility of this method has been demonstrated by the synthesis of a few unprecedented pentacyclic indoles and indole steroidal hybrids. Further, the new methodology has been successfully applied to the enantioselective synthesis of core carbon structure of the polyveoline family of natural products.
A sequential procedure for the synthesis of 2,5-disubstituted thiazoles from terminal alkynes, sulfonyl azides, and thionoesters is reported. A copper(I)-catalyzed 1,3-dipolar cycloaddition of terminal alkynes with sulfonyl azides affords 1-sulfonyl-1,2,3-triazoles, which then react with thionoesters in the presence of a rhodium(II) catalyst. The resulting 3-sulfonyl-4-thiazolines subsequently aromatize
A rhodium-catalyzed reaction of formamides with N-sulfonyl-1,2,3-triazoles is developed to formulate a new one-pot procedure for the direct synthesis of a-amino enaminones from terminal alkynes.