Synthesis of a Water‐Soluble Pd‐Based Catalyst with a Thymine‐Modified β‐Cyclodextrin Ligand for Suzuki Coupling Reactions

Abstract

Herein, the synthesis and crystal structure identification of thymine‐modified β‐cyclodextrin (mono‐(6‐Thymine‐6‐deoxy)‐β‐CD, Thy‐CD) are reported. The catalyst system (Pd@Thy‐CD) was prepared by using the thymine‐modified β‐cyclodextrin as ligand and palladium acetate (Pd(OAc)2) as palladium source. The as‐obtained Pd@Thy‐CD catalyst was characterized by NMR, IR, SEM, and XPS analysis. The catalyst can efficiently catalyze the aqueous phase Suzuki coupling reaction in situ. Under mild reaction conditions, the catalyst system provides excellent yields for the Suzuki coupling reaction of aryl halides, including with aryl chlorides and aryl boronic acids in water. The major advantages of this technique are the ease of preparation of the palladium catalyst, the aqueous phase coupling reaction, the broad functional group tolerance, and the easy recyclability.