A facile asymmetric transfer hydrogenation of ortho-substituted aryl N-heteroaryl ketones and non-ortho-substituted N-oxide of aryl N-heteroaryl ketones using a readily available oxo-tethered ruthenium complex as a catalyst and sodium formate as a hydrogen source in an aqueous solution has been discovered. A variety of chiral aryl N-heteroaryl methanols were obtained with up to 99.9% ee.
Iridium‐Catalyzed Enantioselective Transfer Hydrogenation of Ketones Controlled by Alcohol Hydrogen‐Bonding and
<i>sp</i>
<sup>3</sup>
‐C−H Noncovalent Interactions
Iridium‐catalyzed enantioselective transfer hydrogenation of ketones with formic acid was developed using a prolinol‐phosphine chiral ligand. Cooperative action of the iridium atom and the ligandthrough alcohol‐alkoxide interconversion is crucial to facilitate the transfer hydrogenation. Various ketones including alkyl aryl ketones, ketoesters, and an aryl heteroaryl ketone were competent substrates
Studies on Rhizopus arrhizus mediated enantioselective reduction of arylalkanones
作者:Neeta A Salvi、Subrata Chattopadhyay
DOI:10.1016/s0040-4020(01)00134-x
日期:2001.4
The effect of substitution on the biotransformation of various arylalkanones using Rhizopus arrhizus was investigated. The organism was found to be promising for the reduction of phenylalkanones and arylethanones with good to excellent enantioselectivity. The reduction followed Prelog's rule giving the (S)-carbinols in all the cases. The enantioselectivity of the reaction improved with increasing size
Two Enantiocomplementary Ephedrine Dehydrogenases from <i>Arthrobacter</i> sp. TS-15 with Broad Substrate Specificity
作者:Tarek Shanati、Cameron Lockie、Lilian Beloti、Gideon Grogan、Marion B. Ansorge-Schumacher
DOI:10.1021/acscatal.9b00621
日期:2019.7.5
The recently identified pseudoephedrine and ephedrine dehydrogenases (PseDH and EDH, respectively) from Arthrobacter sp. TS-15 are NADH-dependent members of the oxidoreductase superfamily of short-chain dehydrogenases/reductases (SDRs). They are specific for the enantioselective oxidation of (+)-(S) N-(pseudo)ephedrine and (−)-(R) N-(pseudo)ephedrine, respectively. Anti-Prelog stereospecific PseDH
Iridium-Catalyzed Highly Enantioselective Transfer Hydrogenation of Aryl <i>N</i>-Heteroaryl Ketones with <i>N</i>-Oxide as a Removable <i>ortho</i>-Substituent
作者:Qixing Liu、Chunqin Wang、Haifeng Zhou、Baigui Wang、Jinliang Lv、Lu Cao、Yigang Fu
DOI:10.1021/acs.orglett.7b03878
日期:2018.2.16
A highlyenantioselectivetransferhydrogenation of non-ortho-substituted aryl N-heteroaryl ketones, using readily available chiral diamine-derived iridium complex (S,S)-1f as a catalyst and sodium formate as a hydrogen source in a mixture of H2O/i-PrOH (v/v = 1:1) under ambient conditions, is described. The chiral aryl N-heteroaryl methanols were obtained with up to 98.2% ee by introducing an N-oxide
使用容易获得的手性二胺衍生的铱络合物(S,S)-1f作为催化剂,甲酸钠作为氢源的H 2 O混合物,对非邻位取代的芳基N-杂芳基酮进行高度对映选择性转移氢化/我的i-PrOH(v / v = 1:1)在环境条件下,进行说明。通过引入N-氧化物作为可除去的邻位取代基,获得具有高达98.2%ee的手性芳基N-杂芳基甲醇。相反,在不存在氮的情况下,观察到的ee不超过15.1%-氧化物部分。此外,该协议的实用性还通过克规模的苯磺酸他莫司汀的克级不对称合成以51%的总收率和99.9%的ee进行了证明。