已经开发了一种用于将容易获得的外消旋、支链芳族烯丙酯转化为支链烯丙胺、醚和烷基的催化方案。钯催化的支链烯丙基酯异构化为末端烯丙基酯,然后依次进行铱催化的烯丙基取代,以良好的收率得到支链烯丙基产物,具有高区域异构和对映异构选择性。富电子和缺电子支化烯丙基酯均产生 >90% ee 的产物。对于来自乙酸2-噻吩酯和碳酸二烯酯的反应的产物,也观察到高对映体过量。
Palladium-catalyzed allylic substitution on solid support
作者:Lutz F. Tietze、Thomas Hippe、Adrian Steinmetz
DOI:10.1039/a707670c
日期:——
Different polymer-bound 1,3-dicarbonyl compounds react as nucleophiles in Pd-catalyzed allylic substitutions on solid support with a variety of allylic acetates, chlorides and carbonates.
nickel and chiralamine cooperative catalysis to enable a highlyenantioselectiveallylic alkylation reaction between α-branched aldehydes and a wide scope of allyl esters, allowing the all-carbon quaternary stereocenter to be accessed with excellent enantioselectivity (up to 98% ee) and structural diversity. The general synthetic applicability has been showcased by the enantioselective synthesis of
全碳四元立体中心构成了天然产物和生物活性化合物的重要组成部分。在这里,我们公开了一种镍和手性胺协同催化,使 α-支化醛和各种烯丙基酯之间发生高度对映选择性的烯丙基烷基化反应,从而以优异的对映选择性(高达 98% ee ) 和结构多样性。关键手性构件的对映选择性合成以获取 (+)-依他佐辛、(-)-aphanorphine 和其他两种生物活性化合物,展示了一般合成适用性。
Kinetic resolution of allylic alcohols via stereoselective acylation catalyzed by lipase PS-30
作者:Peiran Chen、Peng Xiang
DOI:10.1016/j.tetlet.2011.08.093
日期:2011.11
By using lipase PS-30 as catalyst, the kineticresolution of a series of racemic allylic alcohols has been achieved via stereoselective acylation. The value of kinetic enantiomeric ratio (E) reached up to 968. Substituent effect is briefly discussed.
Methods for the preparation of 4-hydroxybenzothiophene
申请人:Hoffmann-La Roche Inc.
公开号:US06291685B1
公开(公告)日:2001-09-18
The present invention is concerned with a novel process for the preparation of the hydroxybenzothiophene of formula I
comprising cyclocarbonylation of a compound of formula II
wherein Y is as defined in the specification, followed by saponification. The compound of Formula I is a building block of pharmaceutically active substances, e.g. 5-[4-[2-(5-methyl-2-phenyl-4-oxazolyl)ethoxy]-7-benzothiophenylmethyl]-2,4-thiazolidinedione and the corresponding sodium salt which are from agents useful in the treatment of diabetes.
Enantioselective Allylic Alkylation with 4-Alkyl-1,4-dihydro-pyridines Enabled by Photoredox/Palladium Cocatalysis
作者:Hong-Hao Zhang、Jia-Jia Zhao、Shouyun Yu
DOI:10.1021/jacs.8b10766
日期:2018.12.12
alkylation has been achieved enabled by the merger of photoredox and palladiumcatalysis. In this dual catalytic process, alkyl radicals generated from 4-alkyl-1,4-dihydropyridines act as the coupling partners of the π-allyl palladium complexes. The generality of this method has been illustrated through the reaction of a variety of allylesters with 4-alkyl-1,4-dihydropyridines. This mechanistically novel