贵金属技术的替代以及利用地球上丰富的金属实现新的反应性是可持续合成的核心。迄今为止,烯烃加氢最有效地是通过贵金属催化剂进行的。本研究报道了一种铁催化的三取代和四取代烯烃氢化方案,该方案在温和条件(1-4 bar H 2,20 °C)下具有前所未有的活性和范围。通过分离充当催化剂库和颗粒生长的可溶种子的新型铁纳米簇结构,记录了均相和非均相铁催化界面的指导性快照。
本文中,我们通过配体使能的Au I / Au III催化与金配合物的特质π活化模式的相互作用揭示了金的烯烃1,2-二芳基化反应。与经典的基于迁移插入的方法进行1,2-二芳基化不同,本方法不仅规避了直接Ar-Ar'偶联和Heck型副产物的形成,而且更有趣地证明了其反应性和选择性与先前已知的互补金属催化(Pd,Ni或Cu)。对机理进行详细研究的结果表明,由于芳基烯烃具有非清白的性质,芳基碘化物向Au I络合物的氧化加成是限速步骤。
Iron(II) and Copper(I) Control the Total Regioselectivity in the Hydrobromination of Alkenes
作者:Daniel A. Cruz、Victoria Sinka、Pedro de Armas、Hugo Sebastian Steingruber、Israel Fernández、Víctor S. Martín、Pedro O. Miranda、Juan I. Padrón
DOI:10.1021/acs.orglett.1c02186
日期:2021.8.6
A new method that allows the complete control of the regioselectivity of the hydrobrominationreaction of alkenes is described. Herein, we report a radical procedure with TMSBr and oxygen as common reagents, where the formation of the anti-Markovnikov product occurs in the presence of parts per million amounts of the Cu(I) species and the formation of the Markovnikov product occurs in the presence
A new shelf‐stable and easily scalable difluoromethylthiolating reagent S‐(difluoromethyl) benzenesulfonothioate (PhSO2SCF2H) was developed. PhSO2SCF2H is a powerful reagent for radical difluoromethylthiolation of aryl and alkyl boronic acids, decarboxylative difluoromethylthiolation of aliphatic acids, and a phenylsulfonyl‐difluoromethylthio difunctionalization of alkenes under mild reaction conditions
Catechol diethers as selective PDE.sup.IV inhibitors
申请人:Pfizer Inc.
公开号:US05814651A1
公开(公告)日:1998-09-29
This invention relates to 4-substituted catechol diether compounds which are selective inhibitors of phosphodiesterase (PDE) type IV. The compounds of the present invention are useful in inhibiting PDE.sub.IV and in the treatment of AIDS, asthma, bronchitis, chronic obstructive airways disease, psoriasis, allergic rhinitis, dermatitis and other inflammatory diseases. This invention also relates to pharmaceutical compositions comprising the compounds hereof. ##STR1##
Cobalt-catalyzed hydro-difluoromethylthiolation/hydro-trifluoromethylthiolation of unactivated alkenes
作者:Xinxin Shao、Xin Hong、Long Lu、Qilong Shen
DOI:10.1016/j.tet.2019.05.061
日期:2019.8
ylthiolation reaction of unactivated alkenes was described. Both reactions were conducted at room temperature and a variety of common functional groups such as halogen, ester, aldehyde, enolizable ketone or ester, nitro or cyano group, sulfonate and carbamate were compatible with the reaction conditions. Radical cyclization and radical inhibitor experiments suggested that the reaction proceeds through
biology and drug development in recent years. Here, we report the development of a radical fluorosulfonylation of alkenes/intramolecular arylation cascade for the construction of chromanes with sulfonyl fluoride groups attached. The radical 1,2-fluorosulfonyl arylation reactions proceed well in both endo and exocyclization fashions, allowing for further variation of the distance between the chromane core