Tris(pentafluorophenyl)borane reusable catalyst for hydroalkylation of styrenes with 1, 3-dicarbonyl compounds in PEG

The popularity of boron-based catalysis has increased significantly in the field of organic synthesis over the last few decades. As a prominent group of Lewis acid catalysts, halogenated triarylboranes are a potential hydroalkylation catalyst. This research has proposed an effective method for tris(pentafluorophenyl)borane-catalyzed hydroalkylation of different styrenes with various 1, 3 diketones to generate the corresponding alkylated pentane diones in good to exceptional isolated yields. In the current study, we describe polyethylene glycol (PEG) as an effective solvent for the hydroalkylation of C–C bond formation, catalyzed by tris(pentafluorophenyl)borane (TFPB). We have observed that the catalyst is easily and efficiently recycled during this transition.