Journal of Organic Chemistry p. 6691 - 6702 (2009)
Update date:2022-08-04
Topics:
Aizpurua, Jesus M.
Palomo, Claudio
Fratila, Raluca M.
Ferron, Pablo
Benito, Ana
Gomez-Bengoa, Enrique
Miranda, Jose I.
Santos, Jose I.
(Chemical Equation Presented) Mechanistic details of the Mg2+ ion-activated enantioselective reduction of methyl benzoylformate have been investigated at a B3LYP/6-31G* theory level, using peptide NADH models 1 rigidified with a β-lactam ring. Computation of the reaction pathway revealed important structural differences between the intermediate NADH/Mg 2+/ArCOCO2R ternary complexes 3 and the corresponding transition states leading to enantiomeric methyl mandelates. Thus, ternary complexes showed the dihydronicotinamide moiety placed quasiequatorial to a seven-membered chelation pseudoplane including the two amide carbonyls and the Mg2+ cation, whereas productive transition states were strongly deformed with the dihydronicotinamide group oriented quasiaxial to the chelation pseudoplane. This chelation model was further applied to acyclic nonrigidified NADH models and, based on the fluxional mobility of the peptide chain bonds, experimental enantioselectivities were correctly predicted. Parallel experiments were also conducted in deuterated acetonitrile, using NMR techniques, to study the structure of the binary complexes 2 (NADH/Mg2+) and ternary complexes 3 (NADH/Mg2+/PhCOCO2Me). Finally, owing to the incorporation of two diastereotopic trimethylsilyl NMR-tags in the β-lactam-NADH peptidomimetics, a nonproductive ternary complex predicted by calculations could be observed and its structure characterized on the basis of ROESY experiments and molecular modeling.
View MoreJiangsu Fengshan Group Co., Ltd.
Contact:86-25-86558671
Address:1903,Central International Mansion 105-6 North Zhongshan Road, Nanjing, China
Changsha Huajing Powdery Material Technological Co., Ltd.
Contact:86-731-88879686
Address:Building 2, West Garden, Main Campus of Central South University, Changsha, Hunan Province, China
Weifang Dongxing Chitosan Factory
website:http://dxchitosan.lookchem.com/
Contact:13475651157
Address:Weifang city ,shandong province
Quzhou Ruiyuan chemical Co., Ltd
Contact:+86-570-3039321/3039361/3039308
Address:18# Huayang Road,Quzhou High-tech Industrial Park, Zhejiang China.
Jiangsu Taihu New Materials Holding Co., Ltd
Contact:+86-519-86160108
Address:Xueyan Town, Changzhou City, Jiangsu Province, 213169, China
Doi:10.1016/j.bmc.2013.11.031
(2014)Doi:10.1007/BF00810427
(1988)Doi:10.1007/BF00769651
(1988)Doi:10.1021/jo00086a036
(1994)Doi:10.1021/ja00184a056
(1989)Doi:10.1002/anie.201206624
(2012)