Enantioselective Carbonyl–Ene Reactions Catalyzed by Chiral Cationic Dirhodium(II,III) Carboxamidates
作者:Xichen Xu、Xiaochen Wang、Yuxiao Liu、Michael P. Doyle
DOI:10.1021/jo5013674
日期:2014.12.19
An enantioselectivecarbonyl–enereaction of glyoxylate esters with 1,1-disubstituted alkenes catalyzed by chiral cationic dirhodium(II,III) carboxamidates is described. The paddlewheel dirhodium(II,III) carboxamidates having one open coordination site at each rhodium smoothly catalyze the carbonyl–enereaction to afford homoallylic alcohol products in good isolated yields with high enantioselectivities
<i>C</i><sub>2</sub>-Symmetric Copper(II) Complexes as Chiral Lewis Acids. Enantioselective Catalysis of the Glyoxylate−Ene Reaction
作者:David A. Evans、Christopher S. Burgey、Nick A. Paras、Tomas Vojkovsky、Steven W. Tregay
DOI:10.1021/ja980549m
日期:1998.6.1
ene reaction with glyoxylate esters;3 however, due to the limiting reactivity of the catalyst-glyoxylate complex,4 only nucleophilic 1,1-disubstituted olefins may be employed. We have recently reported that bidentate bis(oxazolinyl) (box) Cu(II) complexes 1-3 are effective enantioselective catalysts in Diels-Alder5 and aldol reactions6 with substrates that can participate in catalyst chelation. In this
Multikilogram Synthesis of a Hepatoselective Glucokinase Activator
作者:Joshua R. Dunetz、Martin A. Berliner、Yanqiao Xiang、Timothy L. Houck、Fabrice H. Salingue、Wang Chao、Chen Yuandong、Wang Shenghua、Yun Huang、Douglas Farrand、Steven J. Boucher、David B. Damon、Teresa W. Makowski、Mark T. Barrila、Raymond Chen、Isamir Martínez
DOI:10.1021/op300194c
日期:2012.10.19
This work describes the process development and manufacture of early-stage clinical supplies of a hepatoselective glucokinase activator, a potential therapy for type 2 diabetes mellitus. Critical issues centered on challenges associated with the synthesis of intermediates and API bearing a particularly racemization-prone a-aryl carboxylate functionality. In particular, a T3P-mediated amidation process was optimized for the coupling of a racemization-prone acid substrate and a relatively non-nucleophilic amine. Furthermore, an unusually hydrolytically-labile amide in the API also complicated the synthesis and isolation of drug substance. The evolution of the process over multiple campaigns is presented, resulting in the preparation of over 110 kg of glucokinase activator.
Heterogeneous Enantioselective Catalyzed Carbonyl- and Imino-Ene Reactions using Copper Bis(Oxazoline) Zeolite Y
作者:Neil A. Caplan、Frederick E. Hancock、Philip C. Bulman Page、Graham J. Hutchings
DOI:10.1002/anie.200352534
日期:2004.3.19
Quasi Solvent-Free Enantioselective Carbonyl-Ene Reaction with Extremely Low Catalyst Loading