Functionalization of Amides via Copper-Catalyzed Oxyalkylation of Vinylarenes and Decarboxylative Alkenylation of sp³ C–H

Abstract

An efficient protocol was developed to prepare a series of derivatives from amides by copper-catalyzed oxyalkylation of vinylarenes and decarboxylative alkenylation of sp(3) C-H. This method is simple, practical, and inexpensive.

A Journey from June 2018 to October 2021 with N,N-Dimethylformamide and N,N-Dimethylacetamide as Reactants

“…The Ni II -catalyzed selective carbamoylation of 1,1-diphenylethene with DMAc under peroxide conditions in the presence of 2-methyl-N-(quinolin-8-yl)benzamide (Scheme 38(g2)) revealed the radical character of the process [125]. Under Cu2O catalysis, oxidation of styrene with Na2S2O8 in DMF provided a 3:1 mixture of N-cinnamyl-N-methylformamide and N,N-dimethylcinnamamide (Scheme 38h) [126]. The Ni(cod)2/t-BuOOH association in DMAc mediated the selective carbamoylation of α,α-diaryl allylic alcohols while amidation was a competitive pathway in DMF (Scheme 38(i1)) [127].…”

“…Cross-coupling with the elimination of the sulfonyl or nitro group was also observed from the reaction of vinylsulfones, ((phenylethynyl)sulfonyl)benzene and β-nitrostyrenes using DM in the presence of either a diaryl ketone under visible-light irradiation (Scheme 39b) [128] or a peroxydisulfate (Scheme 39c) [129]. The CuO-catalyzed reaction of cinnamic acids with DMAc and di-tert-butyl peroxide led to decarboxylative alkenylation giving the corresponding N-cinnamyl-N-methylace tamides (Scheme 39(a 1 )) while 3-methylbut-2-enoic acid afforded (N-methylacetamido) methyl 3-methylbut-2-enoate (Scheme 39(a 2 )) [126]. Cross-coupling with the elimination of the sulfonyl or nitro group was also observed from the reaction of vinylsulfones, ((phenylethynyl)sulfonyl)benzene and β-nitrostyrenes using DM in the presence of either a diaryl ketone under visible-light irradiation (Scheme 39b) [128] or a peroxydisulfate (Scheme 39c) [129].…”

“…Scheme 39. Cross-coupling of α,β-unsaturated acids, vinyl sulfones, ((phenylethynyl)sulfonyl)benzene and β-nitrostyrenes.Treatment at 100 • C of styrene with CuF 2 catalyst and t-BuOOH led to a complicated mixture in DMF while effective production of N-methyl-N-(3-oxo-3-phenylpropyl)acetamide arose in DMAc (Scheme 40)[126]. Various vinylarenes undergo such an oxyalkylation (Scheme 40).…”

Recent Advances in Radical Difunctionalization of Simple Alkenes

“…This method proceeds through a tandem C–H/alkene functionalization step with a broad substrate scope and excellent selectivity control. In the same year, Mao and coworkers also developed a new strategy for selective synthesis of the important class of N ‐(3‐oxo‐3‐phenylpropyl)acetamides from styrenes and N , N ‐substituted amides through copper‐catalyzed oxidative coupling …”

Recent advance in direct sp3 carbon-hydrogen bond functionalizations

“…The process was effectively proved on the α-alkylation of various piperidines with a pyridin-2-yl directing group and provided the corresponding monoalkylated and bisalkylated products with moderate to good yields from readily accessible substrates. Mao and coworkers [37] developed a copper-catalyzed oxidative coupling reaction of N,N-substituted amides with olefins or cinnamic acids for the synthesis of N-(3-oxo-3phenylpropyl)-acetamide and N-cinnamylacetamide derivatives through oxyalkylation of vinylarenes and decarboxylative alkenylation of Csp 3 -H (Scheme 20). The simple and practical protocol could provide the resulting products as potential precursors for the preparation of β-amino carbonyls and cinnamyl amines through further hydrolysis.…”