enantioselective catalytic kinetic resolution of allylic alcohols through asymmetric isomerization with chiralBINOL derivatives-based alkoxides as bifunctional Brønsted base catalysts were described in the study. A number of chiralBINOL derivatives-based alkoxides were synthesized, and their structure-enantioselectivity correlation study in asymmetric isomerization identified a promising chiral Brønsted
Magnesium hemithioacetates were used as model cysteine compounds to mimic natural hemithioacetals, and their biomimetic oxidation reactions using a model NAD+ compound were investigated. Cyclic hemithioacetate was found to be the best substrate for the reaction with the model NAD+ compound, which gave the corresponding NADH analog in excellent yield.
Reduction of activated carbonyl groups by alkyl phosphines: formation of α-hydroxy esters and ketones
作者:Wen Zhang、Min Shi
DOI:10.1039/b516467b
日期:——
Reduction of activated carbonyl groups such as alpha-keto esters, benzils, 1,2-cyclohexanedione, and alpha-ketophosphonates by alkyl phosphines afforded the corresponding alpha-hydroxy esters or ketones in good to excellent yields in THF at room temperature. The mechanism of the proton transfer and intramolecular hydrolysis has been studied on the basis of deuterium and 18O labeling experiments.
A Compact Chemical Miniature of a Holoenzyme, Coenzyme NADH Linked Dehydrogenase. Design and Synthesis of Bridged NADH Models and Their Highly Enantioselective Reduction<sup>1</sup>
作者:Nobuhiro Kanomata、Tadashi Nakata
DOI:10.1021/ja992990y
日期:2000.5.1
pyridine-formation reaction of formyl-substituted (vinylimino)phosphorane 4 with methyl propiolate. The bridged NADH models 10a−c effected excellent biomimetic reduction at various temperatures in the presence of magnesium ion to achieve both the enantioselective and stereospecific reduction of the pyruvate analogues 12u−z into chiral lactate analogues 13u−z with 88−99% ee. The high enantioselectivity was almost
Efficient diastereoselective synthesis of α,β-Dihydroxyesters from methyl phenylglyoxylate and aldehydes mediated by Titanium Trichloride/Pyridine System
作者:Angelo Clerici、Laura Clerici、Luciana Malpezzi、Ombretta Porta
DOI:10.1016/0040-4020(95)00872-6
日期:1995.11
The reductive coupling of methyl phenylglyoxylate 2 with aliphatic and aromatic aldehydes 3, promoted by TiCl3/Py system in anhydrous THF. affords α,β-dihydroxyesters 4 in good yields (60–94%) and high syn-diastereoselectivity (up to 85%) The type of ligand at the metal ion necessary to achieve a high level of diastereocontrol and the possible mechanism involved are discussed