Chemoselectivities in the platinum-catalyzed hydrative carbocyclizations of oxo-alkyne-nitrile functionalities
Anupam Mukherjee1, Rai-Shung Liu
1Department of Chemistry, National Tsing-Hua University, Hsinchu, Taiwan, ROC.
Abstract:
Two new hydrative carbocyclizations of oxa-alkyne-nitrile functionalities are reported to produce distinct nitrogen-containing heterocycles. Protracted heating of oxoalkynyl nitrile substrates with PtCl(2)/CO/H(2)O in hot 1,4-dioxane gave 2,3-dihydro-1H-pyrido[1.2-b]-isoquinolin-4(6H)-ones. In this hydration reaction, dicarbonyl nitrile intermediates were isolated efficiently after a brief period, and they were subjected to an NHC-based crossed benzoin coupling to give spiro alcohols that further reacted with TfOH to give spiro[indene-2,2'-piperidine]-1,6'(3H)-diones.
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