Copper-Catalyzed Intermolecular Alkynylation and Allylation of Unactivated C(sp3)-H Bonds via Hydrogen Atom Transfer
We describe Cu-catalyzed intermolecular alkynylation and allylation of unactivated C(sp3)-H bonds with singly occupied molecular orbital-philes (SOMO-philes) via hydrogen atom transfer (HAT). Employing N-fluoro-sulfonamide as a HAT reagent, a set of subst
Cu-Photoredox-catalyzed C(sp)-C(sp3) coupling of redox-active esters with terminal alkynes
Visible-light-induced C(sp)-C(sp3) coupling of redox-active esters with terminal alkynes has been developed. The activation of carboxylic acids as their redox-active ester derivatives was important for this decarboxylative alkynylation. The strategy established here facilitates the straightforward introduction of triple-bonded functional groups and avoids additional photocatalysts. A wide range of primary, secondary and tertiary acids can be converted into the target products; so this reaction exhibits a broad substrate scope and tolerance of functional groups. Mechanistic experiments suggested that this reaction may undergo a radical process. Under mild reaction conditions, a copper acetylide ligand as a photocatalyst delivered an electron to redox-active ester derivatives, and generated alkyl radicals. The radicals reacted with Cu(ii) to deliver a Cu(iii) complex, and then reductive elimination gave the products.
Zhang, Dayong,Zhang, Yajing
supporting information
p. 4479 - 4483
(2020/10/20)
Graphitic Carbon Nitride Polymer as a Recyclable Photoredox Catalyst for Decarboxylative Alkynylation of Carboxylic Acids
Visible-light-induced heterogeneous photocatalysis for decarboxylative alkynylation has been performed. The using of cheap, metal-free and recyclable graphitic carbon nitride (g-C3N4) as the photoredox catalyst in the process enables
Cu/Ag-catalyzed double decarboxylative cross-coupling reaction between cinnamic acids and aliphatic acids in aqueous solution
A novel double decarboxylative cross-coupling catalyzed by copper and silver has been developed. This method provides a practical approach for the flexible synthesis of alkenes and alkynes from the readily affordable substrates.
Mai, Wen-Peng,Song, Ge,Sun, Gang-Chun,Yang, Liang-Ru,Yuan, Jin-Wei,Xiao, Yong-Mei,Mao, Pu,Qu, Ling-Bo
p. 19264 - 19267
(2013/10/22)
Silver-catalyzed decarboxylative alkynylation of aliphatic carboxylic acids in aqueous solution
C(sp3)-C(sp) bond formations are of immense interest in chemistry and material sciences. We report herein a convenient, radical-mediated and catalytic method for C(sp3)-C(sp) cross-coupling. Thus, with AgNO3 as the catalyst and K2S2O8 as the oxidant, various aliphatic carboxylic acids underwent decarboxylative alkynylation with commercially available ethynylbenziodoxolones in aqueous solution under mild conditions. This site-specific alkynylation is not only general and efficient but also functional group compatible. In addition, it exhibits remarkable chemo- and stereoselectivity.