177722-27-9Relevant academic research and scientific papers
Highly efficient asymmetric Michael addition reaction of malonates to α,β-unsaturated ketones promoted by a chiral thiourea/PPY dual-catalyst system
Moritaka, Maya,Miyamae, Naomu,Nakano, Keiji,Ichikawa, Yoshiyasu,Kotsuki, Hiyoshizo
, p. 2554 - 2558,5 (2012/12/11)
The enantioselective Michael addition reaction of malonates to α,β-unsaturated ketones is efficiently promoted by a combined dual-catalyst system composed of chiral thiourea and 4-pyrrolidinopyridine (PPY) in toluene. The expected Michael adducts with cyclic and acyclic enones are obtained in excellent yields and with excellent enantioselectivities.
Highly efficient asymmetric Michael addition reaction of malonates to α,β-unsaturated ketones promoted by a chiral thiourea/PPY dual-catalyst system
Moritaka, Maya,Miyamae, Naomu,Nakano, Keiji,Ichikawa, Yoshiyasu,Kotsuki, Hiyoshizo
, p. 2554 - 2558 (2013/01/13)
The enantioselective Michael addition reaction of malonates to α,β-unsaturated ketones is efficiently promoted by a combined dual-catalyst system composed of chiral thiourea and 4-pyrrolidinopyridine (PPY) in toluene. The expected Michael adducts with cyclic and acyclic enones are obtained in excellent yields and with excellent enantioselectivities. Georg Thieme Verlag Stuttgart · New York.
Asymmetric michael addition of malonates to enones catalyzed by a primary Β-amino acid and its lithium salt
Yoshida, Masanori,Narita, Mao,Hara, Shoji
experimental part, p. 8513 - 8517 (2011/12/03)
Highly enantioselective Michael addition of malonates to enones was achieved using a mixed catalyst consisting of a primary Β-amino acid, O-TBDPS (S)-Β-homoserine, and its lithium salt. Various cyclic and acyclic enones were converted into 1,5-ketoesters in high yields (up to 92%) with high enantioselectivity (up to 97% ee) under mild reaction conditions. Details of synthesis of the catalyst, optimization of the reaction conditions for the Michael addition reaction, and a plausible reaction mechanism are described.
A new C2-symmetric heterobimetallic complex as a promoter for asymmetric Michael addition reactions
Manickam,Sundararajan
, p. 2271 - 2278 (2007/10/03)
A C2-symmetric chiral amino diol (1R,5R)-3-aza-3-benzyl-1,5-diphenyl pentan-1,5-diol [(R,R)-I] has been synthesised by a modified procedure. The heterobimetallic catalyst [I2-AI-Li] obtained by reaction of the amino diol [(R,R)-I] with LiAlH4, promotes asymmetric Michael addition of malonic esters and thiophenols to α,β-unsaturated compounds with high enantiomeric excess.
Asymmetric induction in Michael addition reactions mediated by C2-symmetric aluminate
Manickam,Sundararajan
, p. 516 - 518 (2007/10/03)
The C2-symmetric chiral amino-diol, (1R, 5R)-3-aza-3- benzyl-1,5-diphenylpentan-1,5-diol (1) is available readily from the reaction of benzylamine with a twofold excess of enantiopure R(+)-styrene epoxide. We have recently shown that the titano
Asymmetric Michael addition of malonate anions to prochiral acceptors catalyzed by L-proline rubidium salt
Yamaguchi, Masahiko,Shiraishi, Tai,Hirama, Masahiro
, p. 3520 - 3530 (2007/10/03)
L-Proline rubidium salt catalyzes the asymmetric Michael addition of malonate anions to prochiral enones and enals. This method can be applied to a wide range of substrates to give adducts with a predictable absolute configuration: (S)-adducts from (E)-enones/enals and (R)-adducts from cyclic (Z)-enones. Both the secondary amine moiety and the carboxylate moiety are critical for the catalytic activity and asymmetric induction. Varying the countercation also affects the reaction course. High enantiomeric excesses were attained when di(tert-butyl) malonate was added to (E)-enones in the presence of CsF. The stereochemistry of the Michael reaction indicates that asymmetric induction takes place via enantioface discrimination involving the acceptor α-carbon atom rather than the β-carbon atom.
