1,4 Asymmetric induction in the carbonyl reduction of a γ-ketosulfoxide
作者:Guy Solladie、Françoise Colobert、Frédéric Somny
DOI:10.1016/s0040-4039(98)02572-6
日期:1999.2
a chiral sulfoxide induced high stereoselectivity in the DIBAL-H reduction of a methyl ketone located in the γ position as a result of a 1,4-asymmetric induction. Addition of a lanthanide triflate or cerium chloride completely reversed the stereoselectivity.
Manganese/Enzyme Sequential Catalytic Pathway for the Production of Optically Active γ-Functionalized Alcohols
作者:Meng Deng、Jiaqi Yang、Zhiyi Kong、Yaning Li、Quanpeng Wang、Huan Liu、Shu-Zhen Deng、Nan Li
DOI:10.1021/acs.joc.4c00776
日期:2024.6.21
the production of opticallyactive γ-functionalized alcohols from relevant alkenes has been developed by using a robust Mn(III)/air/(Me2SiH)2O catalytic system combined with lipase-catalyzedkineticresolution. This approach demonstrates exceptional tolerance toward proximal functional groups present on alkenes, enabling the achievement of high yields and exclusive enantioselectivity. Under this sequential
通过使用稳健的 Mn(III)/空气/(Me 2 SiH) 2 O 催化系统与脂肪酶催化动力学拆分相结合,开发了一种简单实用的催化工艺,用于从相关烯烃生产光学活性 γ-官能化醇。该方法表现出对烯烃上存在的近端官能团的优异耐受性,从而实现高产率和独特的对映选择性。在这种顺序催化系统下,手性烯烃前体也可以转化为γ-官能化醇和相关的乙酸酯作为可分离的单一对映体。
Lipase mediated resolution of 1,3-butanediol derivatives: chiral building blocks for pheromone enantiosynthesis. Part 3
作者:Isidoro Izquierdo、Marı́a T. Plaza、Miguel Rodrı́guez、Juan A. Tamayo、Alicia Martos
DOI:10.1016/s0957-4166(01)00038-6
日期:2001.2
(R,S)-1,3-butanediol 5 was kinetically resolved by enzymatic acetylation with vinyl acetate under the presence of Chirazyme (TM) L-2, c-f, yielding (S)-1-O-acetyl-1,3-hydroxybutane 6 and (R)-1,3-di-O-acetyl-1,3-butanediol 7 with enantiomeric excesses of 91%, (E=67.3). Compounds 6 and 7 were easily transformed into the corresponding (S)-3-O-(2-methoxyethoxymethyl)-3-hydroxybutanal 10 and (R)-3-benzyloxybutanal 19, through a protection-deprotection and functional group interchange methodology. Subsequent reaction of 10 and 19 with 3-(methoxycarbonlypropionyl-methylene)triphenylphosphorane afforded methyl (E,S)-8-O-(2-methoxyethoxymethyl)-4-oxo-5-nonenoate 12 and (E,R)-8-benzyl-oxy-4-oxo-5-nonenoate 20. The alkenes 19 and 20 were then catalytically hydrogenated to the corresponding saturated eaters 13 and 21. Treatment of 13 and 21 with 1,2-ethanedithiol/F3B . OEt2 afforded dithioketals 14 and 22, which were respectively reduced to (S)-1,8-dihydroxy-4-nonanone ethylidenedithioketal 15 and (R)-8-O-benzyl-1,8-dihydroxy-4-nonanone ethylidenedithioketal 23. Finally, deprotection of 15 by catalytic hydrogenation under acidic conditions gave the expected (5S,7S)-(-)-7-methy1-1,6-dioxaspiro[4.5]decane 1. The (5R,7R)-(+)-1 enantiomer was analogously prepared fi om 23. Both compounds were formed by this procedure with an e.e. of 91%. (C) 2001 Elsevier Science Ltd. All rights reserved.
RUTHENIUM COMPLEXES OF PHOSPHINE-AMINOPHOSPHINE LIGANDS