A. Rakshit, Prashant Kumar, Tipu Alam
Sep 9, 2020
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0
Influential Citations
13
Citations
Journal
The Journal of organic chemistry
Abstract
The one-pot synthetic strategies for 2,4,6-triarylnicotinonitriles and 2,5-diaryl-1H-pyrrole-3-carbonitriles have been accomplished via a Pd-catalyzed coupling of arylboronic acid with 2-(3-oxo-1,3-diarylpropyl)malononitrile and 2-(2-oxo-2-arylethyl)malononitrile, respectively under mild reaction conditions followed by intramolecular cyclization of an intermediate formed after the regeneration of catalyst under acidic rection conditions. The cascade reactions proceed in 1,2-dichloroethane solvent under visible-light irradiation, and the active catalyst is generated in situ in the presence of catalytic amounts of Pd(OAc)2 and 2,2'-bipyridine. The active Pd-catalyst undergoes photoexcitation by the virtue of MLCT, and subsequent redox trans-metalation occurs with arylboronic acid, thus obviating the necessity of any exogenous photosensitizer. The targeted products, composed of a new C-C, a C-N, a C=N and two new C=C bonds, were isolated in good yields.