Direct oxidative amidation between methylarenes and amines in water

Abstract

COMMUNICATION This journal isAn environmental friendly direct oxidative amidation between methylarenes and free amines was developed. The aromatic amide could be prepared efficiently from raw chemicals by employing TBHP as the "green" oxidant with the co-catalysis of TBAI and FeCl 3 in water.

Cobalt‐Catalyzed Dehydrogenative Coupling of Alcohols/Aldehydes and Amines: An Important Role for Imine Hydration

“…Such transformation proceeded smoothly even in the presence of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO, 2.0 equiv). [24] In sharp contrast, cobalt/iodide catalysis was completely inhibited under identical conditions (Scheme 6);n o TEMPOa dduct of thea cyl radical was obtained.…”

“…Recently,w ed eveloped ac obalt-catalyzed oxidative esterification of aldehydes, and ac ooperative effect between the cobalt and the chelating iodide ion in the oxidative transformation was extensively discussed. [23] In fact, the protocol in terms of transition-metal-catalyzed oxidative amidation in the presence of iodide ions by using TBHP (as a5 .5 m solution of tert-butyl hydroperoxide (TBHP) in decane) as the oxidant has been proven successful with copper [7] and iron [24] (Scheme1). Interestingly,t he oxidation of iodide ion was found to be as-sisted by FeCl 3 to generate hypoiodites (IO À or IO 2 À )w hich exhibit high activity as oxidizing reagents in the amidation of methylarenes.…”

“…Interestingly,t he oxidation of iodide ion was found to be as-sisted by FeCl 3 to generate hypoiodites (IO À or IO 2 À )w hich exhibit high activity as oxidizing reagents in the amidation of methylarenes. [24] Inspired by these results, we envisioned the coupling of amines,i nsteado fa lcohols, with aldehydeso r their alcoholp recursors under aT BHP/Co II /I À system. To our surprise, mechanistic studies indicated that the in situ-generated tBuO·/tBuOO· rather than the iodine-related IO À /IO 2 À /IO 3 À is the active hydrogen-abstracting species in such catalytic processes.…”

Recent Advances in the Functionalization of Hydrocarbons: Synthesis of Amides and its Derivatives

“…Zhao and co‐workers developed an efficient method for the synthesis of amides by oxidative amidation of methylarenes with free amines by using the combination of TBAI and FeCl 3 .6H 2 O as a catalytic system and TBHP as an oxidant in water as the solvent (Scheme ) . They could promptly synthesize various secondary or tertiary amides with no necessity of organic solvents.…”

Graphene oxide‐catalyzed CSp3–H activation of methylarenes in aqueous medium: A unified metal‐free access to amides and benzimidazoles

“…Recently, the activation of C Sp3 –H bond of methylarenes for C–C and C–hetero bonds formation has received considerable attention . Few synthetic protocols have been reported for the formation of amides using methylarenes and amines, which would be a significant complement to the traditional C–N forming strategies (Scheme b) . Also, in all these, costly heavy metals, i.e.…”