scheme1

Scheme 1. (A) Amidation reaction between amines and carboxylic acids; (B) esterification reaction between carboxylic acids and amine-derived pyridinium salts; (C) this work: decarboxylative alkylation reaction. TPT: 2,4,6-triphenylpyrylium; DMSO: Dimethyl sulfoxide; RT: room temperature.