Palladium-Catalyzed Enantioselective Redox-Relay Heck Arylation of 1,1-Disubstituted Homoallylic Alcohols
作者:Zhi-Min Chen、Margaret J. Hilton、Matthew S. Sigman
DOI:10.1021/jacs.6b06994
日期:2016.9.14
An enantioselective redox-relay oxidative Heck arylation of 1,1-disubstituted alkenes to construct β-stereocenters was developed using a new pyridyl-oxazoline ligand. Various 1,2-diaryl carbonyl compounds were readily obtained in moderate yield and good to excellent enantioselectivity. Additionally, analysis of the reaction outcomes using multidimensional correlations revealed that enantioselectivity
A visible-light mediated exclusively regioselective synthesis of 2,2-disubstituted thio-functionalized tetrahydrofurans, tetrahydro- pyrans and oxepanes has been described through an operationally simple and mild photoredox protocol. Thiyl radical generated from N-phenylsulfenyl phthalimide by photoredox catalysis was proven to be the key reactive intermediate in this reaction.
A facile electrochemical sulfonylative cycloetherification of linear unsaturated alcohols with sulfonyl hydrazides under mild conditions has been accomplished. This catalyst- and oxidant-free protocol proceeds via electro-oxidation, followed by radicaladdition, as well as an intramolecular oxygen nucleophilic process. This methodology is compatible with a broad substrate scope and good functional
Unprecedented hydroxy-alkynylation and -alkenylation reactions of arylalkenes have been developed through electrochemically enabled addition of an organotrifluoroborate reagent and H2O across the double bond of the alkene. The use of electrochemistry to promote these oxidative alkene 1,2-difunctionalization reactions not only obviates the need for transition-metal catalysts and oxidizing reagents but also ensures high regio- and chemoselectivity to afford homopropargylic or homoallylic alcohols. The possibility of extending the electro-chemical alkene difunctionalization strategy to other alkene carbo-heterofunctionalization reactions has been demonstrated.