Direct Asymmetric Hydrogenation and Dynamic Kinetic Resolution of Aryl Ketones Catalyzed by an Iridium‐NHC Exhibiting High Enantio‐ and Diastereoselectivity
of ketones in excellent yields and good enantioselectivity (up to 93 % ee). Moreover, when using racemic α‐substituted ketones, excellent diastereoselectivities were obtained (dr 99:1) by dynamic kinetic resolution of the in situ formed enolate. Overall, the herein described hydrogenation occurs under ambient conditions using low hydrogen pressures, providing a direct and atom efficient method towards
Disclosed herein are therapeutic agents and/or preventive agents for pain or therapeutic agents and/or preventive agents for a sodium channel associated disease. The present invention provides compounds represented by the following formula (I) or pharmacologically acceptable salts thereof:
Acid instead of base: Kineticresolution of secondary alcohols is realized using chiral Brønsted acid catalyzed acylation instead of the conventional basic conditions. A broad range of functional groups are tolerated, such as aldehydes, carboxylic acids, and enoates. The selectivity factor (s) reaches up to 215 at ambient temperature.
From substituent effects to applications: enhancing the optical response of a four-component assembly for reporting ee values
作者:Chung-Yon Lin、Michael W. Giuliano、Bryan D. Ellis、Scott J. Miller、Eric V. Anslyn
DOI:10.1039/c5sc04629g
日期:——
of assemblies formed from select substituted pyridyl ligands pointed to the conclusion that steric effects dominate the mode of interaction at the pyridyl 3- and 6-positions. From these results we identified a new Zn(II)-centered multicomponent assembly with a higher dynamic range than previously reported. Calibration curves of the CD signals resulting from the new assembly led to an ee assay with
Enantioselective synthesis of cis-α-substituted cycloalkanols and trans-cycloalkyl amines thereof
作者:Rosario Fernández、Abel Ros、Antonio Magriz、Hansjörg Dietrich、José M. Lassaletta
DOI:10.1016/j.tet.2007.04.075
日期:2007.7
diastereo- and enantioselective syntheses of trans-cycloalkyl amines was accomplished through a three-step sequence consisting of: (1) asymmetric transfer hydrogenation through dynamickineticresolution of bicyclic and monocyclic α-substituted ketones using HCO2H/Et3N as the hydrogen source and TsDPEN-based Ru(II) catalysts, (2) nucleophilic hydroxyl to azide substitution of the resulting cis-cycloalkanols
通过三个步骤完成反式环烷基胺的非对映和对映选择性合成:(1)通过动态动力学拆分HCO 2 H / Et 3 N作为双环和单环α-取代的酮进行不对称转移氢化。氢源和基于TsDPEN -钌(II)催化剂,(2)的亲核的羟基向所得的叠氮取代的顺式改性Mitsunobu条件下使用-cycloalkanols二苯基磷叠氮化物,和(3)还原的反式-叠氮化物中间体与的LiAlH 4的PPh 3 / H 2 O达到所需目标。