Oxonitriles: a grignard addition-acylation route to enamides.
[reaction: see text] Sequential addition of three different Grignard reagents and pivaloyl chloride to 3-oxo-1-cyclohexene-1-carbonitrile installs four new bonds to generate a diverse array of cyclic enamides. Remarkably, formation of the C-magnesiated nitrile intermediate is followed by preferential acylation by pivaloyl chloride rather than consumption by an in situ Grignard reagent. Rapid N-acylation of the C-magnesiated nitrile generates an acyl ketenimine that reacts readily with Grignard reagents or a trialkylzincate, effectively assembling highly substituted, cyclic enamides.
Fleming
Fraser F
FF
Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530, USA. flemingf@duq.edu
Wei
Guoqing
G
Zhang
Zhiyu
Z
Steward
Omar W
OW
D000215:Acylation; D000577:Amides / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D007202:Indicators and Reagents; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry*
D000577:Amides; D007202:Indicators and Reagents; D009570:Nitriles