Visible-light-induced difunctionalization of β-CF2H-1,3-enynes to access CF2H-containing all-carbon quaternary centers.

Abstract

An efficient and regioselective method for the introduction of a highly functionalized CF₂H-containing quaternary carbon center at the C-2 position of pyridines has been described. This method proceeds via [3 + 2] cycloaddition of β-CF₂H-1,3-enynes with pyridinium ylides, followed by a light-induced aza-Norrish II rearrangement. The salient features of this present protocol include mild reaction conditions, operational simplicity, and excellent C2 site selectivity. Furthermore, the synthetic utility of this method is demonstrated by the downstream functionalization of the resulting products.