Synthesis of Isoquinolines and Pyridines by the Palladium- and Copper-Catalyzed Coupling and Cyclization of Terminal Acetylenes
作者:Kevin R. Roesch、Richard C. Larock
DOI:10.1021/ol990067v
日期:1999.8.1
[GRAPHICS]3-Substituted isoquinolines have been synthesized by the coupling of aryl and alkenyl-substituted terminal acetylenes with the tert-butylimine of o-iodobenzaldehyde in the presence of a palladium catalyst. Alkyl-substituted acetylenes fail to undergo this annulation process. However, the intermediate iminoalkynes containing aryl, alkenyl, and alkyl substituents produced from these palladium-catalyzed reactions undergo copper-catalyzed cyclization in excellent yields and short reaction times. Isoquinolines and pyridines have thus been prepared in a one-pot synthesis via coupling of aryl-, alkenyl-, and alkyl-substituted terminal acetylenes with the tert-butylimines of o-iodobenzaldehydes or 3-halo-5-alkenals in the presence of a palladium catalyst and subsequent copper-catalyzed cyclization of the resulting iminoalkynes. The total synthesis of the isoquinoline natural product decumbenine B has been accomplished in seven steps and 20% overall yield by employing this palladium-catalyzed coupling/cyclization methodology.
Synthesis of Isoquinolines and Pyridines by the Palladium/Copper-Catalyzed Coupling and Cyclization of Terminal Acetylenes and Unsaturated Imines: The Total Synthesis of Decumbenine B
作者:Kevin R. Roesch、Richard C. Larock
DOI:10.1021/jo010579z
日期:2002.1.1
have been developed. However, aryl-, vinylic-, and alkyl-substituted acetylenes undergo palladium-catalyzed coupling and subsequent copper-catalyzed cyclization in excellent yields. The totalsynthesis of the isoquinoline natural product decumbenine B has been accomplished in seven steps and 20% overall yield by employing this palladium-catalyzed coupling and cyclization methodology.