Asymmetric Henry reaction catalyzed by C2-symmetric tridentate bis(oxazoline) and bis(thiazoline) complexes: metal-controlled reversal of enantioselectivity.J Org Chem. 2005 Apr 29; 70(9):3712-5.JO
Abstract
[reaction: see text] C(2)-symmetric tridentate bis(oxazoline) and bis(thiazoline) ligands with a diphenylamine backbone have been investigated in the catalytic asymmetric Henry reaction of alpha-keto esters with different Lewis acids. Their Cu(OTf)(2) complexes furnished S enantiomers, while Et(2)Zn complexes afforded R enantiomers, both of them with higher enantioselectivities (up to 85% ee). Reversal of enantioselectivity in asymmetric Henry reactions was achieved with the same chiral ligand by changing the Lewis acid center from Cu(II) to Zn(II). The results show that the NH group in C(2)-symmetric tridentate chiral ligands plays a very important role in controlling both the yields and enantiofacial selectivity of the Henry products.
Pub Type(s)
Journal Article
Language
eng
PubMed ID
15845012
Citation
Du, Da-Ming, et al. "Asymmetric Henry Reaction Catalyzed By C2-symmetric Tridentate Bis(oxazoline) and Bis(thiazoline) Complexes: Metal-controlled Reversal of Enantioselectivity." The Journal of Organic Chemistry, vol. 70, no. 9, 2005, pp. 3712-5.
Du DM, Lu SF, Fang T, et al. Asymmetric Henry reaction catalyzed by C2-symmetric tridentate bis(oxazoline) and bis(thiazoline) complexes: metal-controlled reversal of enantioselectivity. J Org Chem. 2005;70(9):3712-5.
Du, D. M., Lu, S. F., Fang, T., & Xu, J. (2005). Asymmetric Henry reaction catalyzed by C2-symmetric tridentate bis(oxazoline) and bis(thiazoline) complexes: metal-controlled reversal of enantioselectivity. The Journal of Organic Chemistry, 70(9), 3712-5.
Du DM, et al. Asymmetric Henry Reaction Catalyzed By C2-symmetric Tridentate Bis(oxazoline) and Bis(thiazoline) Complexes: Metal-controlled Reversal of Enantioselectivity. J Org Chem. 2005 Apr 29;70(9):3712-5. PubMed PMID: 15845012.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR
T1 - Asymmetric Henry reaction catalyzed by C2-symmetric tridentate bis(oxazoline) and bis(thiazoline) complexes: metal-controlled reversal of enantioselectivity.
AU - Du,Da-Ming,
AU - Lu,Shao-Feng,
AU - Fang,Tao,
AU - Xu,Jiaxi,
PY - 2005/4/23/pubmed
PY - 2005/4/23/medline
PY - 2005/4/23/entrez
SP - 3712
EP - 5
JF - The Journal of organic chemistry
JO - J Org Chem
VL - 70
IS - 9
N2 - [reaction: see text] C(2)-symmetric tridentate bis(oxazoline) and bis(thiazoline) ligands with a diphenylamine backbone have been investigated in the catalytic asymmetric Henry reaction of alpha-keto esters with different Lewis acids. Their Cu(OTf)(2) complexes furnished S enantiomers, while Et(2)Zn complexes afforded R enantiomers, both of them with higher enantioselectivities (up to 85% ee). Reversal of enantioselectivity in asymmetric Henry reactions was achieved with the same chiral ligand by changing the Lewis acid center from Cu(II) to Zn(II). The results show that the NH group in C(2)-symmetric tridentate chiral ligands plays a very important role in controlling both the yields and enantiofacial selectivity of the Henry products.
SN - 0022-3263
UR - https://www.unboundmedicine.com/medline/citation/15845012/Asymmetric_Henry_reaction_catalyzed_by_C2_symmetric_tridentate_bis_oxazoline__and_bis_thiazoline__complexes:_metal_controlled_reversal_of_enantioselectivity_
DB - PRIME
DP - Unbound Medicine
ER -
