C-C (alkynylation) vs C-O (ether) bond formation under Pd/C-Cu catalysis: Synthesis and pharmacological evaluation of 4-alkynylthieno[2,3-d]pyrimidines

Abstract

The Pd/C-CuI-PPh3 catalytic system facilitated C-C bond formation between 4-chlorothieno[2,3-d]pyrimidines and terminal alkynes in methanol with high selectivity without generating any significant side products arising from C-O bond formation between the chloro compounds and methanol. A variety of novel 4-alkynylthieno[2,3-d]pyrimidines were prepared via alkynyl-ation of 4-chlorothieno[2,3-d]pyrimidines in good to excellent yields. Some of the compounds synthesized were tested for cyto-toxic activity in vitro.