Amine-Tunable Ruthenium Catalysts for Asymmetric Reduction of Ketones
作者:Sonia Rodríguez、Bo Qu、Keith R. Fandrick、Frederic Buono、Nizar Haddad、Yibo Xu、Melissa A. Herbage、Xingzhong Zeng、Shengli Ma、Nelu Grinberg、Heewon Lee、Zhengxu S. Han、Nathan K. Yee、Chris H. Senanayake
DOI:10.1002/adsc.201300727
日期:2014.2.10
AbstractA series of efficient ruthenium catalysts has been developed for the asymmetric hydrogenation and transfer hydrogenation of ketones with high reactivities and selectivities. The new chiral bisdihydrobenzooxaphosphole (BIBOP)/diamine‐ruthenium complexes catalyzed the enantioselective hydrogenation of substrates such as aryl and heteroaryl cyclic and alkyl ketones with substrate/catalyst (S/C) ratios of up to 100,000. The opposite sense of enantioselectivity can be obtained by proper selection of a diamine with a given chirality of the phosphine. The usefulness of the new system has been demonstrated in the asymmetric hydrogenation of a complex synthetic intermediate towards cholesteryl ester transfer protein (CETP) inhibitors at S/C 20,000 on large‐scale operation.magnified image
Preparative access to medicinal chemistry related chiral alcohols using carbonyl reductase technology
作者:Andrew S. Rowan、Thomas S. Moody、Roger M. Howard、Toby J. Underwood、Iain R. Miskelly、Yanan He、Bo Wang
DOI:10.1016/j.tetasy.2013.09.015
日期:2013.11
Libraries of highly enantioenriched secondary alcohols in both enantiomeric forms were synthesised by enzymatic reduction of their parent ketones using selectAZyme (TM) carbonyl reductase (CRED) technology. Commercially available CREDs were able to reduce a range of substrate classes efficiently and with very high enantioselectivity. Matching substrate classes to small subsets of CREDs enabled the fast development of preparative bioreductions and the rapid generation of 100-1500 mg samples of chiral alcohols in typically >95% ee and the majority in >= 99.0% ee. The conditions for small scale synthesis were then scaled up to 0.5 kg to deliver one of the chiral alcohols, (S)-1-(4-bromophenyl)-2-chloroethanol, in 99.8% ee and 91% isolated yield. (C) 2013 Elsevier Ltd. All rights reserved.
A Practical Asymmetric Synthesis
of the ACNO Fragment of Morphine Alkaloids
作者:Ling-Wei Hsin、Li-Te Chang、Huei-Ling Liou
DOI:10.1055/s-2008-1078021
日期:——
Asymmetric total synthesis of the ACNO skeleton of morphinealkaloids has been achieved in excellent overall yields and optical purities using the Ru-catalyzed asymmetric transfer hydrogenation, Pd-catalyzed cyclization, and Pt-catalyzed hydrogenation as key steps.