aminohydroxyphosphine ligand was developed for copper-catalyzed asymmetric conjugateaddition of organozinc reagents to alpha,beta-unsaturated carbonyl compounds. This new tridentate ligand induces consistently high enantioselectivity in reactions of a variety of acyclic substrates. Theoretical mechanistic analysis suggests that the C-C bond formation takes place through a highly ordered transition state by the coordination
Enantioselective Conjugate Addition of Dialkylzinc and Diphenylzinc to Enones Catalyzed by a Chiral Copper(I) Binaphthylthiophosphoramide or Binaphthylselenophosphoramide Ligand System
作者:Min Shi、Chun-Jiang Wang、Wen Zhang
DOI:10.1002/chem.200400254
日期:2004.11.5
The enantioselective conjugate addition of dialkylzinc or diphenylzinc to enones was catalyzed by a copper(I)-axially chiral binaphthylthiophosphoramide or binaphthylselenophosphoramide ligand system at room temperature (20 degrees C) or 0 degrees C, affording the Michael adducts in high yields with excellent ee for cyclic and acyclic enones. The enantioselectivity and reaction rate achieved here are
Amino-sugar modular ligands—useful cores for the formation of asymmetric copper 1,4-addition catalysts
作者:Antonella De Roma、Francesco Ruffo、Simon Woodward
DOI:10.1039/b813137f
日期:——
Modular phosphine ligands, synthesised rapidly from commercial N-acetylglucosamine, are very effective in copper(I)-catalysed 1,4-additions of ZnR2 to linear aliphatic enones (87â95% ee).
CHIRAL TRIDENTATE COMPOUNDS, CORRESPONDING ORGANOMETAL COMPLEXES, METHOD FOR PREPARING SAME AND USE OF SAID COMPOUNDS AND COMPLEXES AS LIGANDS IN ASYMMETRICAL CATALYSIS
申请人:Mauduit Marc
公开号:US20100267956A1
公开(公告)日:2010-10-21
The invention relates to a compound of the formula (I) or the formula (II) in which: W is an oxygen atom or a radical of the formula NH; X is hydrogen or an alkaline cation or a C1-C8 alkyl or a —(CH
2
)
n
3
—C(R
4
)(R
5
)(R
6
) radical; X and R on the one hand and X and R
1
on the other hand may independently form an optionally substituted cycle with 5, 6 or 7 links. The invention also relates to complexes of said compounds with at least one metal selected from the group comprising copper, palladium, ruthenium, iridium and rhodium, and to a method for the synthesis of these compounds. These compounds and complexes can be used in various asymmetrical catalysis methods.
Enantioselective copper catalysed 1,4-conjugate addition reactions using chiral N-heterocyclic carbenes
作者:Caroline L. Winn、Frédéric Guillen、Julien Pytkowicz、Sylvain Roland、Pierre Mangeney、Alexandre Alexakis
DOI:10.1016/j.jorganchem.2005.07.024
日期:2005.12
The preparation of a variety of chiral N-heterocyclic carbene (NHC) precursors is described. The relative merits of imidazolinium salts and silver carbenes as NHC precursors are discussed with respect to their synthesis, stability and performance in the copper catalysed conjugate addition of dialkyl zinc reagents to a variety of Michael acceptors. Enantioselectivities of up to 93% were achieved using