Ir(ppy)<sub>3</sub>-Catalyzed, Visible-Light-Mediated Reaction of α-Chloro Cinnamates with Enol Acetates: An Apparent Halogen Paradox
作者:Thomas Föll、Julia Rehbein、Oliver Reiser
DOI:10.1021/acs.orglett.8b02484
日期:2018.9.21
activation of vinyl chloridesderivedfrom α-chloro ethyl cinnamates via oxidative quenching of excited photocatalyst fac-Ir(ppy)3 is described. Upon photoelectron transfer and chloride extrusion, the corresponding vinyl radical can be efficiently trapped by enol acetates, giving rise to synthetically useful 1,4-dicarbonyl compounds in good to excellent yields. This transformation is distinguished by
A convenient method for the synthesis of (Z)-α-haloacrylates: Lewis base-catalyzed carbonyl olefination using α-halo-C,O-bis(trimethylsilyl)ketene acetals
synthesis of (Z)-α-haloacrylates from variousaldehydes that uses α-halogenated ethyl-C,O-bis(trimethylsilyl)keteneacetals in the presence of a Lewis base catalyst such as acetate salts was established. This procedure gives the corresponding α-halo-α,β-unsaturated esters in high yields with excellent stereoselectivity from E/Z mixtures of ketene silyl acetals under mild conditions.