Photocatalytic chemo-, regio- & stereoselective olefinic β-C–H decarboxylative alkylation of enamides with diacyl peroxides

Abstract

A decarboxylative alkylation of enamides with alkyl diacyl peroxides induced by visible-light is described. The chemo-, regio- and stereoselective olefinic β-C–H alkylation generates a series of primary- and secondary alkylated...

Alkyl radicals from diacyl peroxides: metal-/base-/additive-free photocatalytic alkylation of N-heteroaromatics

“…13 Moreover, Pan and Yu's group disclosed a Ru-photocatalyzed decarboxylative alkylation of enamides with alkyl diacyl peroxides under visible-light irradiation (Scheme 1e). 14 It should be noted that transition metal photocatalysts, additives, and conventional organic solvents are still unavoidable in the previously reported photocatalytic systems.…”

Copper- or iron-catalyzed stereoselective methylation of enamides using dicumyl peroxide as the methyl source

“…In summary, we have described an efficient approach for the sustainable copper- or iron-catalyzed methylation of enamides by employing DCP as the methylating reagent. 29 The protocol provides a facile pathway leading to a broad range of β-C(sp 2 )-methylated enamides in a E -selective manner. Mechanistically, this transformation proceeded through a plausible free radical pathway.…”

Photo‐Induced C−H Methylation Reactions

“…Under light irradiation, Int-16 a undergoes LMCT, leading to the formation of an alkoxy radical (Int-16 b) and a Ce(III) species. Subsequently, Int-16 b abstracts a hydrogen atom from methane, resulting in the generation of a methyl radical that is captured by di-tert-butyl (E)-diazene-1,2-dicarboxylate (DBAD) (46). The resulting N-centered radical is then reduced by the Ce(III) species, yielding the final product (47) after further protonation, along with the regeneration of the active Ce(IV) species.…”

“…In 2023, Pan and colleagues successfully developed a visible-light-driven decarboxylative methylation reaction of enamides using alkyl dialkanoyl peroxides as the alkylating agent (Scheme 17). [46] This achievement resulted in the synthesis of a diverse range of substituted (E)-alkylenamides with impressive yields. Notably, when methyl diacetyl peroxide (43) was employed, direct methylation of N-benzyl-N-(1phenylvinyl)acetamide (42) was accomplished, yielding the desired product, (E)-N-benzyl-N-(1-phenylprop-1-en-1yl)acetamide (44), as a single geometric isomer with a yield of 69 %.…”