A general and highly efficient method for asymmetric sequential hydrogenation of α,β-unsaturated ketones has been developed by using an iridium/f-Ampha complex as the catalyst, furnishing corresponding chiral alcohols with two contiguous stereocenters in high yields with excellent diastereo- and enantioselectivities (up to 99% yield, >20 : 1 dr and >99% ee). Control experiments indicated that the CC
通过使用铱/f-Ampha 配合物作为催化剂,开发了一种通用且高效的 α,β-不饱和酮的不对称顺序氢化方法,以高收率提供具有两个连续立体中心的相应手性醇,并具有优异的非对映和对映选择性(高达 99% 的产率,>20 : 1 dr 和 >99% ee)。对照实验表明,烯酮的 C C 和 C O 键依次氢化,最终的立体选择性由酮的动态动力学拆分决定。此外,DFT 计算表明,外球途径参与了 C C 和 C的减少。O 烯酮键。该方法的合成效用通过克级反应和极低催化剂负载量 (S/C = 20 000) 和获得抗哮喘药物 CP-199,330 的关键手性中间体的简明合成路线得到证明。
[EN] PRODUCTION OF ISOFLAVONE DERIVATIVES<br/>[FR] DERIVES D'ISOFLAVONE
申请人:NOVOGEN RES PTY LTD
公开号:WO2000049009A1
公开(公告)日:2000-08-24
Methods for the hydrogenation of isoflavones are described which provide access to workable quantities of isoflavan-4-ols, isoflav-3-enes, and isoflavans. The isoflavone derivatives can be obtained in high purity and in near quantitative yields whilst employing pharmaceutically acceptable reagents and solvents.
Methods for the hydrogenation of isoflavones are described which provide access to workable quantities of isoflavan-4-ols, isoflav-3-enes, and isoflavans. The isoflavone derivatives can be obtained in high purity and in near quantitative yields whilst employing pharmaceutically acceptable reagents and solvents.
An efficient RuPHOX−Ru catalyzed asymmetric cascade hydrogenation of 3-substitutedchromones has been achieved under mild reaction conditions, affording the corresponding chiral 3-substituted chromanols in high yields with excellent enantio- and diastereoselectivities. A dynamic kinetic resolution process occurs during the subsequent hydrogenation of the C=O double bond, which is responsible for the
Absolute configurations of isoflavan-4-ol stereoisomers
作者:Dongho Won、Bok-Kyu Shin、Suil Kang、Hor-Gil Hur、Mihyang Kim、Jaehong Han
DOI:10.1016/j.bmcl.2008.01.116
日期:2008.3
Isoflavan-4-ol has been synthesized quantitatively from the reduction of isoflavone in the presence of Pd/C and ammonium formate under N(2) atmosphere. Isolation of cis- and trans-isomers was achieved by. ash column chromatography and each enantiomer was separated by Sumi-Chiral column chromatography. Absolute configurations of four stereoisomers were determined by circular dichroism spectroscopy. (C) 2008 Elsevier Ltd. All rights reserved.