CdSe nanoplatelets as photocatalyst for organic photochemistry: Synthesis of amino acid derivatives by decarboxylative alkylation of aldimines

Abstract

Colloidal semiconductor two dimensional CdSe nanoplatelets (NPLs) have been widely applied in photophysics, while rarely used in photocatalytic reactions. Here we show that CdSe NPLs act as photocatalyst in visible light-driven radical alkylation of aldimines, with 2,2′-bipyridine (BPY) as an additive. The photocatalytic reaction gave amino-acid derivatives in reliably good yields with various alkyl radical precursors. Furthermore, CdSe NPLs recycled from the reactions remain active and can be reused. The structural and photoelectric properties of fresh and recycled NPLs were characterized using XRD, XPS, TEM, EDS, TRPL, DRS and electrochemical analysis, revealing that BPY can bind to the surface defects of NPLs and adjust the relative oxidation and reduction potentials. As the synthesis of CdSe NPLs is low-cost, convenient and available at industrial scales, the results suggest NPLs could serve as a practical choice of photocatalyst for organic photochemistry.