Friedel-Crafts Alkylations of Arenes with Mono- and Bis(trifluoromethyl)oxiranes in Superacid Medium: Facile Synthesis of α-(Trifluoromethyl)- and α,α-Bis(Trifluoromethyl)-β-Arylethanols
Triflic acid catalyzed Friedel-Crafts alkylation of aromatics with mono- and bis(trifluoromethyl)oxiranes through ring opening afforded α-(trifluoromethyl) and α,α-bis(trifluoromethyl)-β-phenylethanols in excellent yields. The regioselectivity of the -oxirane ring opening and subsequent Friedel-Crafts alkylation have been found to depend on the electronic and steric effects of the -substituents in