Preparation of chitosan/cellulose composite copper catalyst for green synthesis in the construction of C–Si bonds in aqueous phase

In this work, a new kind of green chitosan/cellulose composite copper gelatinous microbead (CC@Cu) was prepared by a crosslinking method and could perform as an efficient heterogeneous catalyst for the silylation of alpha,beta-unsaturated acceptors in aqueous phase under mild conditions without bases. A broad substrate scope has been explored, including alpha,beta-unsaturated carbonyl compounds, MBH alcohols, quinone compounds, and pharmaceutical molecules. Remarkably, this protocol provides a direct and efficient pathway to achieve an important class of beta-silyl carbonyl compounds, and the desired products were obtained in good to excellent yields. Moreover, the catalyst could be recovered easily and work effectively in six recycles. The advantages of this newly developed process include operational simplicity, good functional group tolerance, avoidance of the use of bases, scalability, ready availability, and easy recyclability of the catalyst.