The present invention relates to a compound of formula (I) and salts thereof,
The present invention further relates to catalytic complexes comprising a compound of formula I and uses thereof in the stereoselective synthesis of stereocentres, in particular, all-carbon quaternary stereocentres.
Acyclic quaternary centers from asymmetric conjugate addition of alkylzirconium reagents to linear trisubstituted enones
作者:Zhenbo Gao、Stephen P. Fletcher
DOI:10.1039/c6sc02811j
日期:——
Synthetic methods for the selective formation of all carbon quaternary centres in non-cyclic systems are rare. Here we report highly enantioselective Cu-catalytic asymmetric conjugate addition of alkylzirconium species to twelve...
New asymmetricconjugatereduction of beta,beta-disubstituted alpha,beta-unsaturated ketones and esters was accomplished with alkoxylhydrosilanes in the presence of chiral rhodium(2,6-bisoxazolinylphenyl) complexes in high yields and high enantioselectivity. (E)-4-Phenyl-3-penten-2-one and (E)-4-phenyl-4-isopropyl-3-penten-2-one were readily reduced at 60 degrees C in 95 % ee and 98 % ee, respectively
Sodium Tetraarylborates as Effective Nucleophiles in Rhodium/Diene-Catalyzed 1,4-Addition to β,β-Disubstituted α,β-Unsaturated Ketones: Catalytic Asymmetric Construction of Quaternary Carbon Stereocenters
A rhodium-catalyzed1,4-addition of sodium tetraarylborates to beta,beta-disubstituted alpha,beta-unsaturated ketones is described. Highly efficient asymmetric catalysis has also been achieved by employing a readily available chiral diene ligand, leading to the construction of quaternary carbon stereocenters with high enantioselectivity.
Rhodium-Catalyzed Asymmetric 1,4-Addition of Sodium Tetraarylborates to β,β-Disubstituted α,β-Unsaturated Esters
作者:Ryo Shintani、Tamio Hayashi
DOI:10.1021/ol102674z
日期:2011.1.21
A rhodium-catalyzed1,4-addition of sodium tetraarylborates to β,β-disubstitutedα,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.