72681-05-1Relevant articles and documents
Regiocontrol in alkylation of lithium dienediolates of unsaturated carboxylic acids
Brun,Gil,Parra
, p. 156 - 159 (2001)
Alkylation of dienediolates from unsaturated carboxylic acids with benzylic halides often results in mixtures of regioisomers. However it can be controlled by adequate modification of the reaction conditions. Thus, addition of DMI leads mainly to the α-re
Enantioselective Hydrogenation of β,β-Disubstituted Unsaturated Carboxylic Acids under Base-Free Conditions
Yan, Qiaozhi,Kong, Duanyang,Zhao, Wei,Zi, Guofu,Hou, Guohua
, p. 2070 - 2077 (2016/03/15)
An additive-free enantioselective hydrogenation of β,β-disubstituted unsaturated carboxylic acids catalyzed by the Rh-(R,R)-f-spiroPhos complex has been developed. Under mild conditions, a wide scope of β,β-disubstituted unsaturated carboxylic acids were hydrogenated to the corresponding chiral carboxylic acids with excellent enantioselectivities (up to 99.3% ee). This methodology was also successfully applied to the synthesis of the pharmaceutical molecule indatraline.
Highly efficient Rh-catalyzed asymmetric hydrogenation of α,β-unsaturated nitriles
Yan, Qiaozhi,Kong, Duanyang,Li, Meina,Hou, Guohua,Zi, Guofu
supporting information, p. 10177 - 10181 (2015/09/01)
A highly efficient enantioselective hydrogenation of α,β-unsaturated nitriles catalyzed by Rh-(R,R)-f-spiroPhos complex has been developed. With Rh-(R,R)-f-spiroPhos catalyst and under mild conditions, a wide range of α,β-unsaturated nitriles including the (E)- and (Z)-isomers of 3-alkyl-3-aryl, 3,3-diaryl, and 3,3-dialkyl α,β-unsaturated nitriles were hydrogenated to the corresponding chiral nitriles with excellent enantioselectivities (up to 99.9% ee) and high turnover numbers (TON up to 10,000).
Cu-catalyzed formal methylative and hydrogenative carboxylation of alkynes with carbon dioxide: Efficient synthesis of α,β-unsaturated carboxylic acids
Takimoto, Masanori,Hou, Zhaomin
, p. 11439 - 11445 (2013/09/02)
The sequential hydroalumination or methylalumination of various alkynes catalyzed by different catalyst systems, such those based on Sc, Zr, and Ni complexes, and the subsequent carboxylation of the resulting alkenylaluminum species with CO2 catalyzed by an N-heterocyclic carbene (NHC)-copper catalyst have been examined in detail. The regio- and stereoselectivity of the overall reaction relied largely on the hydroalumination or methylalumination reactions, which significantly depended on the catalyst and alkyne substrates. The subsequent Cu-catalyzed carboxylation proceeded with retention of the stereoconfiguration of the alkenylaluminum species. All the reactions could be carried out in one-pot to afford efficiently a variety of α,β- unsaturated carboxylic acids with well-controlled configurations, which are difficult to construct by previously reported methods. This protocol could be practically useful and attractive because of its high regio- and stereoselectivity, simple one-pot reaction operation, and the use of CO 2 as a starting material. Copyright
Rhodium-catalyzed asymmetric 1,4-addition of sodium tetraarylborates to β,β-disubstituted α,β-unsaturated esters
Shintani, Ryo,Hayashi, Tamio
supporting information; experimental part, p. 350 - 352 (2011/03/22)
A rhodium-catalyzed 1,4-addition of sodium tetraarylborates to β,β-disubstituted α,β-unsaturated esters has been developed. Highly efficient asymmetric catalysis has also been described to create quaternary carbon stereocenters at the β-position of esters by tuning the ester group of substrates and employing a readily available chiral diene ligand.
Enantioselective Conjugate Reduction of α,β-Unsaturated Carboxamides with Semicorrin Cobalt Catalysts
Matt, Peter von,Pfaltz, Andreas
, p. 691 - 700 (2007/10/02)
Chiral semicorrin cobalt complexes, prepared in situ from cobalt(II) chloride and the free ligands, are efficient, highly enantioselective catalysts for the conjugate reduction of α,β-unsaturated carboxamides with sodium borohydride.Enantiomeric excesses of up to 99percent, essentially quantitative yields, and high substrate/catalyst ratios (1000-10 000:1) are attractive attributes of this catalytic process.