Dynamic kinetic resolution of α-chloro β-keto esters and phosphonates: hemisynthesis of Taxotere® through Ru-DIFLUORPHOS asymmetric hydrogenation
摘要:
The dynamic kinetic resolution (DKR) of racemic alpha-chloro beta-ketoesters and alpha-chloro beta-ketophosphonates through ruthenium-mediated asymmetric hydrogenation is reported. The corresponding alpha-chloro beta-hydroxyesters and alpha-chloro beta-hydroxyphosphonates were obtained in good to high enantio- and diastereomeric excesses using, in particular, the atropisomeric ligand DIFLUORPHOS. This methodology allowed an efficient preparation of the anti phenylisoserine side chain of Taxotere (R) which has been used for the hemisynthesis of the cancer therapeutic agent itself. In addition, C-13 NMR in chiral oriented solvents was used to investigate the DKR effect. (C) 2010 Elsevier Ltd. All rights reserved.
[EN] ASPARAGINE DERIVATIVES AND METHODS OF USING SAME<br/>[FR] DÉRIVÉS D'ASPARAGINE ET LEURS PROCÉDÉS D'UTILISATION
申请人:SENDA BIOSCIENCES INC
公开号:WO2021252640A1
公开(公告)日:2021-12-16
The present disclosure relates to compounds of formulas (A) and (I), pharmaceutically acceptable salts thereof, and solvates of any of the foregoing, pharmaceutical compositions comprising the same, methods of preparing the same, intermediate compounds useful for preparing the same, and methods for treating or prophylaxis of diseases, in particular cancer, such as colorectal cancer, using the same.
作者:Xuan B. Nguyen、Yuji Nakano、Nisharnthi M. Duggan、Lydia Scott、Martin Breugst、David W. Lupton
DOI:10.1002/anie.201905475
日期:2019.8.12
Direct polarity inversion of conjugate acceptors provides a valuable entry to homoenolates. N‐heterocyclic carbene (NHC) catalyzed reactions, in which β‐unsubstituted conjugate acceptors undergo homoenolate formation and C−C bond formation twice, have been developed. Specifically, the all‐carbon (5+1) annulations give a range of mono‐ and bicyclic cyclohexanones (31 examples). In the first family of
The reactivity of several products R1R2CH-X+,1, (X=N,P,S), which can produce ylids by reaction with bases, has been tested using the activated bariumhydroxidecatalysts, C-200. Wittig-Horner, Wittig, Corey-Chaykovsky and Kröhnke type reactions have been analyzed. The pKa of 1, and the structure of active sites control the process. When 1 has a strong acid character, the process takes place -dissolving
已使用活化的氢氧化钡催化剂C-200测试了几种产物R 1 R 2 CH-X +,1(X = N,P,S)的反应性,这些产物可通过与碱反应生成碘。对Wittig-Horner,Wittig,Corey-Chaykovsky和Kröhnke型反应进行了分析。pKa为1,以及活性位点的结构控制着这一过程。当1具有强酸特性时,将发生过程-将固体溶解-形成均相。当1的pKa值<11时,该过程在固体的强碱位置(pKa> 11.7)进行,该位点控制了反应机理和吸附的类固醇的反应性。
SYNTHESIS OF BENZANNELATED TRISDEHYDRO[10.10.2][14]ANNULENO[14]ANNULENES
annulenoannulenes consisting of two same size nuclei should be fused systems of two diatropic moieties. In order to obtain further information on the nature of annulenoannulene, the synthesis of dibenzo- and benzotrisdehydro[14]annuleno[14]annulenes has been performed.
Iridium(III)-Catalyzed C−H Functionalization of Triarylphosphine Oxides with Diazo Dicarbonyl Compounds: Synthesis of α-Aryl 1,3-Dicarbonyl Derivatives
作者:Shang-Dong Yang、Qin-Xin Lou、Jing-Yu Li
DOI:10.1055/a-1409-1906
日期:2021.8
A novel (pentamethylcyclopenta-1,3-dienyl)iridium(III)-catalyzed direct C–H functionalization of triarylphosphine oxides with diazo dicarbonyl compounds through carbene insertion has been developed. This strategy provides a simple and efficientroute to the construction of α-arylated 1,3-dicarbonyl compounds, which are important building blocks in pharmaceutical chemistry.