Catalysed asymmetric reaction of aldehydes with dialkylzinc in the presence of chiral pyridyl alcohols as ligands
摘要:
The synthesis of homochiral pyridyl alcohols (1,2,3a-c) and a catalytic asymmetric addition of dialkylzinc to various aldehydes using 1-3 as ligands are described. Although the reaction of benzaldehyde with Et2Zn in the presence of (S)-1 and (R,R)-2 gave (S)- and (R)-1-phenyl-1-propanol, respectively, in moderate enantiomeric excess (e.e.), tridentate ligands (3a-c) accelerated the reaction to produce the corresponding alcohols in high e.e. Particularly, (S)-3b was found to be the most efficient catalyst, for which asymmetric reactions of various aldehydes with dialkylzinc gave the corresponding alcohols in good to high e.es. (up to 95% e.e.).
A Highly Active Manganese Catalyst for Enantioselective Ketone and Ester Hydrogenation
作者:Magnus B. Widegren、Gavin J. Harkness、Alexandra M. Z. Slawin、David B. Cordes、Matthew L. Clarke
DOI:10.1002/anie.201702406
日期:2017.5.15
A newhydrogenationcatalyst based on a manganese complex of a chiral P,N,N ligand has been found to be especially active for the hydrogenation of esters down to 0.1 mol % catalyst loading, and gives up to 97 % ee in the hydrogenation of pro‐chiral deactivated ketones at 30–50 °C.
Enantioselective Hydrogenation and Transfer Hydrogenation of Bulky Ketones Catalysed by a Ruthenium Complex of a Chiral Tridentate Ligand
作者:M. Belén Díaz-Valenzuela、Scott D. Phillips、Marcia B. France、Mary E. Gunn、Matthew L. Clarke
DOI:10.1002/chem.200801929
日期:2009.1.19
substrates such as bulky heterocyclic ketones. Unusually for a pressure hydrogenation catalyst, similar enantioselectivity can be obtained under transferhydrogenation conditions. The transferhydrogenations are somewhat slower than the pressure hydrogenations, but this drawback is readily overcome, since we have discovered that a microwave accelerated transferhydrogenation of the above ketones occurs within
Synthesis of (1,1′)-2,6-bis[1-(diphenylphosphino)ethyl]pyridine and its application in asymmetric transfer hydrogenation
作者:Qiongzhong Jiang、Daniel Van Plew、Shahid Murtuza、Xumu Zhang
DOI:10.1016/0040-4039(95)02298-8
日期:1996.2
A C2 symmetric tridentate ligand, (1R, 1R′) 2,6-Bis[1-(diphenylphosphino)ethyl]pyridine, has been synthesized in enantiomerically pure form. A practical method to synthesize a variety of chiral pyridyl diols is reported. Asymmetrictransferhydrogenation is achieved using the tridentate ligand.
AC 2对称三齿配体(1R,1R')2,6-双[1-(二苯基膦基)乙基]吡啶已以对映体纯形式合成。报道了一种合成各种手性吡啶基二醇的实用方法。使用三齿配体实现不对称转移氢化。
Asymmetric synthesis catalyzed by transition metal complexes with new
申请人:The Penn State Research Foundation
公开号:US05767276A1
公开(公告)日:1998-06-16
A chiral ligand having the following structure: ##STR1## wherein AR is any aromatic and/or ring structure, and R is selected from the group consisting of aryl, oxygenated aryl, alkyl, oxygenated alkyl, AR, oxygenated AR and combinations thereof.
[EN] ASYMMETRIC SYNTHESIS CATALYZED BY TRANSITION METAL COMPLEXES WITH NEW CHIRAL LIGANDS<br/>[FR] SYNTHESE ASYMETRIQUE CATALYSEE PAR DES COMPLEXES DE METAUX DE TRANSITION ASSOCIES A DE NOUVEAUX LIGANDS CHIRAUX
申请人:THE PENN STATE RESEARCH FOUNDATION
公开号:WO1997013763A1
公开(公告)日:1997-04-17
(EN) A chiral ligand having structure (I) wherein AR is any aromatic and/or ring structure, and R is selected from the group consisting of aryl, oxygenated aryl, alkyl, oxygenated alkyl, AR, oxygenated AR and combinations thereof.(FR) L'invention porte sur un ligand chiral représenté par la formule (I), où AR est une structure aromatique et/ou cyclique, et R est choisi dans le groupe constitué d'aryle, d'aryle oxygéné, d'alkyle, d'alkyle oxygéné, d'AR, d'AR oxygéné, et de leurs combinaisons.