Iron-Mediated Reductive Amidation of Triazine Esters with Nitroarenes

Abstract

A reductive amidation of triazine esters with nitroarenes by using cheap iron as a reducing metal in the presence of TMSCl in DMF was developed. The reactions proceeded efficiently under transition metal-free conditions to give the corresponding amides in moderate to good yields with good functional group compatibility. Preliminary mechanistic investigations indicated that nitrosobenzene, N-phenyl hydroxylamine, azoxybenzene, azobenzene, aniline, and N-arylformamide possibly served as the intermediates of the reaction.

Hydroxylation of Aryl Sulfonium Salts for Phenol Synthesis under Mild Reaction Conditions

“…Although the hydroxylation of aryl thianthrenium salts have been accomplished by using water as hydroxide source, the reaction should be conducted under photoredox conditions in the presence of Ir and Cu catalysts [ 74 ]. In the continuation of our efforts to develop efficient organic transformations with the use of alternative electrophiles [ 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 ] under mild reaction conditions, herein we report a hydroxylation of aryl sulfonium salts by using acetohydroxamic acid and oxime as hydroxylative agents, which enabled the efficient assembly of hydroxylated arenes in modest-to-good yields with good functional group compatibility ( Scheme 1 d).…”

Sulfur-Mediated Decarboxylative Amidation of Cinnamic Acids via C═C Bond Cleavage

“…Nitroarenes have also been employed as precursors of amines to create the amide bond via reductive amidation of preactivated carboxylic acids (cf. Scheme A) . The reductive amidation generally requires the use of metal catalysts to reduce the nitro group and to couple it with the activated acids.…”