Difluorocarbene-Triggered Acyl Rearrangement Reaction: A Strategy for the Direct Introduction of the gem-Difluoromethylene Group

Abstract

A novel metal-and catalyst-free dearomative reaction of 2-oxypyridines to construct gem-difluoromethylenated Nsubstituted 2-pyridones has been developed. The reaction involves an attractive acyl rearrangement from O to CF 2 of difluorocarbene-derived pyridinium ylides, which provides a new strategy for the direct introduction of the gem-difluoromethylene group with high efficiency and selectivity as well as broad substrate scope. Gram-scale synthesis and synthetic transformations have also been demonstrated.

Gold(i)-catalyzed synthesis of N-alkenyl 2-pyridonyl sec-amines

“…3 In addition to these techniques, methods such as migration, alkylation, addition, and rearrangement of the derivatives of pyridine and pyridone are commonly used to produce this skeleton. 4 N -Alkylated 2-pyridones, which may form from 6- endo-dig addition or O-to-N migrations, can be obtained using 2-propargyloxypyridine derivatives. 5…”