20469-72-1Relevant articles and documents
Nickel-Catalyzed Directed Hydroarylation of Alkynes with Boronic Acids
Hanna, Luke E.,Konev, Mikhail O.,Jarvo, Elizabeth R.
supporting information, p. 184 - 187 (2018/12/05)
A regio- and stereoselective nickel-catalyzed hydroarylation of alkynes using propargylic carbamates as directing groups has been developed. The reaction proceeds under mild reaction conditions using arylboronic acids in the absence of base. A range of heterocycles and functional groups are tolerated under the reaction conditions, providing high yields of trisubstituted alkenes with control of olefin geometry.
Synthesis of β,β-disubstituted indanones via the Pd-catalyzed tandem conjugate addition/cyclization reaction of arylboronic acids with α,β-unsaturated esters
Gao, Ang,Liu, Xiu-Yan,Li, Hao,Ding, Chang-Hua,Hou, Xue-Long
, p. 9988 - 9994 (2018/05/31)
Under Pd catalysis with a newly synthesized electron-deficient heterocycle, 2-(4,5-dihydroimidazol-2-yl)- pyrimidine (as the ligand), the reaction of α,β-unsaturated esters with arylboronic acids afforded a wide range of 3,3-disubstituted indan-1-ones bearing a quaternary carbon in high yields. Mechanistic studies revealed that the reaction involves a tandem conjugate addition/1,4-Pd shift followed by a cyclization.
Single-isomer trisubstituted olefins from a novel reaction of (E)-βchloro-α-iodo-α,β-unsaturated esters and amides
Simard-Mercier, Julie,Jiang, Jojo Liu,Ho, Michael L.,Flynn, Alison B.,Ogilvie, William W.
, p. 5899 - 5906 (2008/12/21)
(Chemical Equation Presented) (E)-β-Chloro-α-iodo-α, β-unsaturated esters are converted to single isomer trisubstituted olefins bearing three different carbon substituents by cross-coupling under reflux. Mechanistic investigations suggest that this process transfers a hydrogen from the boronic acid to the α-position of the substrate and then introduces an aryl group to the β-position of the intermediate template while replacing chloride. The reaction is highly stereoselective, showing preference for the E-isomer. The process proceeds through (E)-β-chloro-α-aryl-α, β-unsaturated esters that are transformed efficiently into the corresponding E-products through stereoselective Suzuki-type reactions giving single isomers. The observed stereo-chemistry is apparently enabled by the intermediacy of a palladium allenoate. The reaction involves a catalytic cycle in which PdII is reduced to Pd0 through the formation of biaryl-coupled products.