A straightforward and efficient C(sp2)–H acylation of enamides with aldehydes via transition-metal-free photoredox catalysis is demonstrated. The transformation proceeded smoothly without resorting to expensive and potentially toxic iridium or ruthenium polypyridyl-based photocatalysts under mild conditions, furnishing a diverse range of synthetically crucial, geometrically defined β-acylated enamides
only: An atom‐economical synthetic route towards arylated Z‐enamides through double CH functionalization is described. The Z/E selectivity of the palladium‐catalyzed monoarylation is absolute (step A in scheme), and the molecular complexity of the products can be further endowed by a sequential second arylation, which requires the use of trifluoracetic acid (TFA; step B).
Catalytic charge transfer complex enabled difluoromethylation of enamides with difluoromethyltriphenylphosphonium bromide
作者:Ping Li、Qiang Liu、De-Qun Sun、Xiang-Yu Chen
DOI:10.1039/d2ob01539k
日期:——
A catalytic chargetransfercomplex strategy that enabled difluoromethylation and ethoxycarbonylmonofluoromethylation of enamides with phosphonium bromine salts has been reported. This strategy also provides a convenient approach for the synthesis of functionalized oxindoles and 1,1-diphenylethylenes with easily available phosphonium bromine salts and a catalytic amount of iodine anion.
Transition-metal-free regioselective and stereoselective C(sp<sup>2</sup>)–C(sp<sup>3</sup>) coupling of enamides with ethers or alkanes <i>via</i> photoredox-catalyzed cross-dehydrogenative coupling reactions
A generally applicable and robust regio- and stereoselective cross-dehydrogenative-coupling of enamides with ethers or alkanes via transition-metal-free photoredox-catalysis under environmentally benign and atom economic conditions is demonstrated. The visible-light-induced transformations proceed smoothly with the aid of non-expensive and non-poisonous organic dyes, forging geometrically defined and