An organophosphine‐catalyzed enantioselective cyanosilylation of carbonyl compounds has been disclosed for the first time. This process, the dual‐reagent catalysis serves as a powerful tool, affording the desired cyanohydrin trimethylsilyl ethers in excellent yields (up to 99 %) and good‐to‐excellent enantioselectivities (up to 94 % ee).
[EN] INDAZOLES AS GLUCOCORTICOID RECEPTOR LIGANDS<br/>[FR] NOUVEAUX COMPOSÉS
申请人:GLAXO GROUP LTD
公开号:WO2009050243A1
公开(公告)日:2009-04-23
The present invention provides compounds of formula (I), a process for their preparation, to pharmaceutical compositions comprising the compounds and the preparation of said compositions, to intermediates, and to use of the compounds for the manufacture of a medicament for therapeutic treatment, particularly for the treatment of inflammation and/or allergic conditions.
Synthesis of 2,5-dihydrofurans via alkylidene carbene insertion reactions
作者:Louise F. Walker、Ahmed Bourghida、Stephen Connolly、Martin Wills
DOI:10.1039/b111097g
日期:2002.3.25
The insertion reaction of alkylidene carbenes is demonstrated to be an effective method for the synthesis of 2,5-dihydrofuran ring systems. The best results have been obtained on substrates containing electron-withdrawing substituents, which appear less prone to the competing rearrangement reaction. This insight has led to the development of a new method for the synthesis of the core structure of the squalestatin–zaragozic acid natural products.
Total Synthesis of (+)-Mycotrienol and (+)-Mycotrienin I: Application of Asymmetric Crotylsilane Bond Constructions
作者:Craig E. Masse、Michael Yang、Jason Solomon、James S. Panek
DOI:10.1021/ja9743194
日期:1998.5.1
synthesis. All fourstereogeniccenters were introduced using chiral allylsilane bond construction methodology. In the synthesis of subunit 3b, the C12 and C13 stereocenters were installed using an asymmetric crotylsilylation reaction to α-keto dibenzyl acetal 5. The C11 stereocenter was subsequently installed via a chelate-controlled addition of allyltrimethylsilane to establish the anti-1,3-diol system
Bifunctional N,N‘-dioxide catalysts have been developed for highly enantioselective cyanosilylation of α,α-dialkoxy ketones. This process, catalyzed by in-situ-prepared proline-derived N,N‘-dioxide 2b, produced the corresponding cyanohydrin trimethylsilyl ethers in excellent yields (up to 99%) with high enantioselectivities (up to 93% ee). A reasonable mechanism was proposed according to the observation
双官能N,N- '二氧化物催化剂已经被开发用于α的高度对映选择性的硅氰化反应,α二烷氧基酮。此过程中,通过催化的原位制备的脯氨酸衍生Ñ,Ñ '二氧化物2b中,所产生的相应的氰醇三甲基甲硅烷基醚以优良产率(高达99%)的高对映选择性(高达93%ee)的。根据线性效应,1 H NMR谱图,分离的氰醇以及催化剂的NH和N-氧化物部分的作用,提出了合理的机理。