Nucleophile-Catalyzed, Facile, and Highly Selective C–H Activation of Fluoroform with Pd(II)

Exceedingly facile (23 °C) and
chemoselective H-CF3 activation with [(dppp)­Pd­(Ph)­(OH)]
in the presence of a Lewis base
promoter such as n-Bu3P leads to Pd-CF3 bond formation in nearly quantitative yield. A combined experimental
and computational study points to a new mechanism that involves H-bonding
Pd-O­(H)···H-CF3 and nucleophilic attack
of the promoter on the metal, followed by a push-pull-type collapse
of the resultant five-coordinate Pd­(II) intermediate via a polar transition
state.