A water-mediated C–H activation using sulfoxonium ylides is reported, providing a general, green and step-economic approach to construct a C–C bond and varieties of useful N-heterocycle scaffolds. Notably, the “water-mediated” activation, in contrast to that in organic solvents, shows great potential in pharmaceutical, biochemistry and chemical industries.
Cobalt‐Mediated Decarboxylative/Desilylative C−H Activation/Annulation Reaction: An Efficient Approach to Natural Alkaloids and New Structural Analogues
A Co(II)- mediated decarboxylative/desilylative C−H activation/annulation reaction for the synthesis of 3-arylisoquinoline derivatives has been developed with a good functional group tolerance and wide applications.
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.