Cu-Catalyzed C–H Trifluoromethylation of 3-Arylprop-1-ynes for the Selective Construction of Allenic Csp²–CF₃ and Propargyl Csp³–CF₃ Bonds

Abstract

A new method has been developed for the Cu-catalyzed C-H trifluoromethylation of 3-arylprop-1-ynes for the selective construction of allenic Csp(2)-CF3 and propargyl Csp(3)-CF3 bonds. The selective formation of allenic Csp(2)-CF3 and propargyl Csp(3)-CF3 bonds can be controlled by modifying the reaction conditions.

Simple Synthesis of Fluorinated Ene-Ynes via In Situ Generation of Allenes

“…Similar isomerization patterns have been observed from aryl substituted trifluoromethyl allenes. 38 Upon further GC-MS and NMR spectra analysis (Scheme 3C, Figure S3), we proposed the compound with a 5.85 min retention (Scheme 2B, hash) arose from the activated alkyne 11. Unfortunately, we were unable to obtain an ana- 10) standard and reaction conditions A-C. (C) NMR spectra of the mixture of products isolated from reaction mixture C. 1 H NMR (top trace), 13 C NMR (middle trace), and 19 F NMR (bottom trace).…”

Progress in copper-catalyzed trifluoromethylation

“…Recently, the group of Xiao and Lin [ 65 ] developed a copper-catalyzed C–H trifluoromethylation of 3-arylprop-1-ynes to provide (trifluoromethyl)allenes and propargyl trifluoromethanes ( Scheme 44 ). This reaction was the first reported example for selective construction of allenic C(sp 2 )−CF 3 and propargyl C(sp 3 )−CF 3 bonds by modifying the reaction conditions.…”

Palladium-Catalyzed Fluoroarylation of gem-Difluoroenynes to Access Trisubstituted Trifluoromethyl Allenes

“…One is regioselectivity control, which is commonly encountered in the synthesis of allene through enyne caused by 1,2/1,4-addition or 1,3-shift; ,,, the other is the transmetalation ability of the silver intermediate, which tends to decompose . Herein, we report the first fluoroarylation of gem -difluoroenynes with aryl halides leading to trisubstituted trifluoromethyl allenes that could be achieved by combination of palladium/triphenylphosphine catalyst and silver fluoride (Scheme b) …”