Palladium-catalysed aminocarbonylation/cyclization of iodoalkenes toward N-propargylcarboxamides and oxazoles
Péter Szuroczki, Gábor Mikle, László Kollár
Index: 10.1016/j.mcat.2018.03.015
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Abstract
Palladium(0) complexes formed in situ from a palladium(II) precursor, Pd(OAc)2, proved to be highly active catalytic system in aminocarbonylation of the variety of iodoalkenes (1-iodocyclohexene, 4-tert-butyl-1-iodocyclohexene, 2-methyl-1-iodocyclohexene, α-iodostyrene, 2-iodobornene, 17-iodoandrost-16-ene, 17-iodo-3-methoxyestra-1,3,5(10),16-tetraene, 20-iodo-3β-hydroxypregna-5,20-diene) using propargylamine and its derivatives as N-nucleophile. While the carboxamides formed from the parent propargylamine and its 1,1-dimethyl substituted derivative underwent palladium-catalysed ring-closure reaction resulting in the corresponding oxazoles and oxazolines, respectively, the carboxamides formed from N-methylpropargylamine are reluctant toward any cyclization.