Cobalt-Catalyzed Chemodivergent Synthesis of Cyclic Amines and Lactams from Ketoacids and Anilines Using Hydrosilylation

J Org Chem. 2023 Dec 15;88(24):16997-17009. doi: 10.1021/acs.joc.3c01870. Epub 2023 Nov 29.

Abstract

Here, commercially available Co2(CO)8 was utilized as an efficient catalyst for chemodivergent synthesis of pyrrolidines and pyrrolidones from levulinic acid and aromatic amines under slightly different hydrosilylation conditions. 1.5 and 3 equiv of phenylsilane selectively yielded pyrrolidone and pyrrolidine, respectively. Various ketoacids and amines were successfully tested. Plausible mechanism involves the condensation of levulinic acid and amine to form an imine, which cyclizes to 3-pyrrolidin-2-one followed by reduction to pyrrolidone. The final reduction of pyrrolidone gave pyrrolidine.