Cellulose supported TiO₂/Cu₂O for highly asymmetric conjugate addition of α,β-unsaturated compounds in aqueous phase

A series of new kind green cellulose-supported bimetallic TiO₂/Cu₂O (Cell@TiO₂/Cu₂O) catalytic materials were obtained by in-situ reduction method employing cellulose as the carrier. The effects of metal percentage composition on the morphology and construction of the catalytic materials were systematically investigated. The Cell@TiO₂/Cu₂O were characterized by FT-IR, TG, XPS, SEM, TEM, EDS, and the element content was obtained by elemental analysis. Then, the achieved catalytic materials were applied to the chiral borylation reaction of α,β-unsaturated compounds, including nitrile compounds, esters, and α,β-unsaturated ketones. Remarkably, this approach provides an efficient strategy to gain an important class of chiral organic boron compounds with target chiral products in high yields as well as enantioselectivities. Besides, the Cell@TiO₂/Cu₂O could be easily recycled and effectively reused. This work constructed bimetallic TiO₂/Cu₂O on cellulose as a newly catalyst to obtain chiral boron compounds in aqueous phase.