B(C6 F5 )3 -Catalyzed Tandem Friedel-Crafts and C-H/C-O Coupling Reactions of Dialkylanilines

Chem Asian J. 2020 Oct 1;15(19):3082-3086. doi: 10.1002/asia.202000763. Epub 2020 Sep 7.

Abstract

Tandem Friedel-Crafts (FC) and C-H/C-O coupling reactions catalyzed by tris(pentafluorophenyl) borane (B(C6 F5 )3 ) were achieved without using any other additive in the absence of solvent. This process can be used for the reactions between a series of dialkylanilines and vinyl ethers with good isolated yields of bis(4-dialkylaminophenyl) compounds. Based on combined theoretical and experimental studies, the possible reaction mechanism was proposed. B(C6 F5 )3 can activate the C=C and C-O bond for FC and C-H/C-O coupling reactions respectively. The FC reaction is slow, which is followed by a fast C-H/C-O coupling.

Keywords: B(C6F5)3; C−H/C−O Coupling; Density functional calculation; Friedel-Crafts; Lewis acid.