The first regiodivergent opening of unbiased epoxides providing the ring-opened products in high enantiomeric excess from racemic and exceptionally high enantiomeric excess from enantioenriched substrates in a double asymmetric process has been devised. It constitutes a more general case of the very important enantioselective openings of meso-epoxides.
The first regiodivergent opening of unbiased epoxides providing the ring-opened products in high enantiomeric excess from racemic and exceptionally high enantiomeric excess from enantioenriched substrates in a double asymmetric process has been devised. It constitutes a more general case of the very important enantioselective openings of meso-epoxides.
[EN] METHOD OF CONVERTING ALCOHOL TO HALIDE<br/>[FR] PROCÉDÉ DE CONVERSION D'UN ALCOOL EN HALOGÉNURE
申请人:UNIV SAARLAND
公开号:WO2016202894A1
公开(公告)日:2016-12-22
The present invention relates to a method of converting an alcohol into a corresponding halide. This method comprises reacting the alcohol with an optionally substituted aromatic carboxylic acid halide in presence of an N-substituted formamide to replace a hydroxyl group of the alcohol by a halogen atom. The present invention also relates to a method of converting an alcohol into a corresponding substitution product. The second method comprises: (a) performing the method of the invention of converting an alcohol into the corresponding halide; and (b) reacting the corresponding halide with a nucleophile to convert the halide into the nucleophilic substitution product.
Synthesis and Application of Stereoretentive Ruthenium Catalysts on the Basis of the M7 and the Ru–Benzylidene–Oxazinone Design
作者:Adrien Dumas、Daniel S. Müller、Idriss Curbet、Loïc Toupet、Mathieu Rouen、Olivier Baslé、Marc Mauduit
DOI:10.1021/acs.organomet.7b00836
日期:2018.3.12
catalysts bearing the dithiocatecholate ligand was synthesiszed on the basis of the M7 and Ru–benzylidene–oxazinone design. The activity of the catalysts was tested in ring-opening cross-metathesisreactions, ring-closing metathesis reactions, cross-metathesisreactions, and self-metathesis reactions using Z- and E-configured starting materials. The desired metathesis products were obtained with moderate to
Synthesis of N-heterocycles, beta-amino acids, and allyl amines via aza-payne mediated reaction of ylides and hydroxy aziridines
申请人:Borhan Babak
公开号:US20090012120A1
公开(公告)日:2009-01-08
An ylide-based aza-Payne rearrangement of 2,3-aziridin-
1
-ols leads to an efficient process for the preparation of pyrrolidines. The aza-Payne rearrangement under the basic reaction conditions favors the formation of epoxy amines. Subsequent nucleophilic attack of the epoxide by the ylide yields a bis-anion, which upon a 5-exo-tet ring closure yields the desired pyrrolidine, thus completing the relay of the 3-membered the 5-membered nitrogen containing ring system. This process takes place with complete transfer of stereochemical fidelity, and can be applied to sterically hindered aziridinols.
[EN] CATALYSTS FOR EFFICIENT Z-SELECTIVE METATHESIS<br/>[FR] CATALYSEURS POUR UNE MÉTATHÈSE Z-SÉLECTIVE EFFICACE
申请人:TRUSTEES BOSTON COLLEGE
公开号:WO2014201300A1
公开(公告)日:2014-12-18
The present application provides, among other things, compounds and methods for metathesis reactions. In some embodiments, provided compounds promote highly efficient and highly Z-selective metathesis. In some embodiments, provided compounds and methods are particularly useful for producing allyl alcohols. In some embodiments, provided compounds have the structure of formula I. In some embodiments, provided compounds comprise ruthenium, and a ligand bonded to ruthenium through a sulfur atom.
High-value alcohols and higher-oxidation-state compounds by catalytic Z-selective cross-metathesis
作者:Ming Joo Koh、R. Kashif M. Khan、Sebastian Torker、Miao Yu、Malte S. Mikus、Amir H. Hoveyda
DOI:10.1038/nature14061
日期:2015.1
high-value compounds by cross-metathesis. The ruthenium complex is prepared from a commercially available precursor and an easily generated air-stable zinc catechothiolate. Transformations typically proceed with 5.0 mole per cent of the complex and an inexpensive reaction partner in 4–8 hours under ambient conditions; products are obtained in up to 80 per cent yield and 98:2 Z:E diastereoselectivity.
烯烃复分解催化剂为生命科学领域的医生和研究人员提供了必不可少的分子。然而,一个持续存在的问题是缺乏直接生成无环 Z 烯丙醇的化学转化,包括含有受阻相邻取代基或反应性功能单元(如苯酚、醛或羧酸)的产品。在这里,我们提出了一种电子改性的二硫化钌催化剂,它可以通过交叉复分解有效地产生这种高价值的化合物。钌配合物由市售前体和易于生成的空气稳定儿茶酚硫醇锌制备。在环境条件下,转化通常在 4-8 小时内以 5.0 摩尔百分比的配合物和廉价的反应伙伴进行;以高达 80% 的产率和 98:2 Z:E 非对映选择性获得产品。该催化剂的使用已在天然抗肿瘤剂 Neopeltolide 的合成以及可再生原料(油酸)向抗真菌剂的一步立体选择性克级转化中得到证明。在这种转化中,新催化剂比常用的二氯钌配合物更有效地促进交叉复分解,表明其效用可能超出 Z 选择性过程。