General Synthesis of <i>N</i>-CF<sub>3</sub> Heteroaryl Amides via Successive Fluorination and Acylation of Sterically Hindered Isothiocyanates
作者:Min Tao、Jiasheng Qian、Zuanguang Chen、Lin-Kun An、David M. Wilson、Jianbo Liu
DOI:10.1021/acs.joc.3c01740
日期:2023.11.3
We report the one-pot synthesis of N-CF3 heteroaryl amides (NTFMHA) from heteroaryl carboxylic acids and sterically hindered isothiocyanates, including various amino acid analogues, in the presence of AgF. The key to this reaction is the utilization of free heteroaryl acyl chlorides, rather than their corresponding hydrochloride salts. This method represents a complementary method of our previous work
Chiral, nonracemic, N-unprotected amino acids were converted into the corresponding N-benzimidazol-2-yl derivatives by a sequential procedure involving initial formation of isothiocyanates, their reaction with arene-1,2-diamines, and cyclization-desulfurization of the intermediate thioureas with iodoacetic acid. The simplified workup and the lack of volatile or toxic byproducts in the key desulfurization step renders iodoacetic acid a superior reagent to the usual reagent, iodomethane.