Copper(I)‐Catalyzed Alkylation of Polyfluoroarenes through Direct CH Bond Functionalization

Abstract

The copper(I)-catalyzed alkylation of electron-deficient polyfluoroarenes with N-tosylhydrazones and diazo compounds has been developed. This reaction uses readily available starting materials and is operationally simple, thus representing a practical method for the construction of C(sp(2) )-C(sp(3) ) bonds with polyfluoroarenes through direct C-H bond functionalization. Mechanistically, copper(I) carbene formation and subsequent migratory insertion are proposed as the key steps in the reaction pathway.

Copper‐Catalyzed Direct Cross‐Coupling of Compounds Containing Activated C–H/Heteroatom–H Bonds with N‐Tosylhydrazones

“…[37] Alternative approaches for the alkylation of polyfluoroarenes that have successively emerged in last few years compete with the upcoming Cu-catalyzed methodology. [38] Notably, the development of Cu I -carbene-based migratory insertion of polyfluoroarenes has become the most efficient and simple method addressing the challenges associated with the alkylation of polyfluoroarenes.…”

Palladium‐Catalyzed Intramolecular Self‐Alkylation of Polyfluoroarene via Heck and Decarboxylation Process

“…[1] Polyfluoroarenes, as a representative class of such F-compounds molecules, have been found extensive application in pharmaceuticals, active materials, electronic devices and complex natural products. [3] Subsequently, numerous cross-coupling reactions of polyfluoroarenes were reported by the Daugulis, [4] Zhang, [5] Su, [6] Larrosa, [7] Wang [8] and other groups, [9] which are mostly catalyzed by copper or palladium to coordinate with the deprotonated polyfluoroarenes. In 2006, Fagnou and coworkers described the first palladium-catalyzed direct arylation of polyfluoroarenes to provide various fluorine-containing biaryl compounds.…”

Palladium‐Catalyzed Intramolecular Carbene Insertion into C(sp3)−H Bonds

“…[4] Although other metals have emerged as potentially useful catalysts for this type of transformation, [5][6][7][8][9][10] the use of palladium has been restricted to ac ouple of examples of a-diazo b-ketoester insertion into C(sp 2 )ÀH bonds. [11,12] This fact is highly surprising if we take into account the great success of Pd catalysis in cross-coupling reactions of diazo compounds with either organic halides or arylboronic acids.…”

“…[3,4] Our investigation began by testing the Pd-catalyzed cyclization of a-diazoester 1 in order to assess the regioselectivity of the CÀHb ond activation process (Scheme 2).…”