C=C双键与分子氧的氧化裂解产生羰基化合物是化学和药物合成中的一个重要转化。在自然界中,含有第一排过渡金属的酶,特别是血红素和非血红素铁依赖性酶,在环境条件下很容易激活 O 2并以极其精确的方式氧化裂解 C=C 键。然而,该反应对合成化学家来说仍然具有挑战性。只有少数已知的合成金属催化剂允许在 O 2大气压下氧化裂解烯烃,很少有人知道催化未活化烯烃的裂解。在这项工作中,我们描述了一种光驱动、Mn 催化的协议,用于在 1 个大气压的 O 2下将烯烃选择性氧化为羰基化合物。首次使用第一排生物相关金属催化剂,在清洁、温和的条件下,可以将芳香族和各种未活化的脂肪族烯烃氧化成酮和醛。此外,该协议显示出非常好的功能组耐受性。机理研究表明,Mn-oxo 物种,包括不对称的混合价双 (μ-oxo)-Mn(III,IV) 络合物,参与氧化,溶剂甲醇参与 O 2活化,导致oxo 物种的形成。
[EN] MACROCYCLIC BROAD SPECTRUM ANTIBIOTICS<br/>[FR] ANTIBIOTIQUES MACROCYCLIQUES À LARGE SPECTRE
申请人:RQX PHARMACEUTICALS INC
公开号:WO2018149419A1
公开(公告)日:2018-08-23
Provided herein are antibacterial compounds, wherein the compounds in some embodiments have broad spectrum bioactivity. In various embodiments, the compounds act by inhibition of bacterial type 1 signal peptidase (SpsB), an essential protein in bacteria. Pharmaceutical compositions and methods for treatment using the compounds described herein are also provided.
Silver‐Catalysed Hydroarylation of Highly Substituted Styrenes
作者:Toryn Dalton、Steffen Greßies、Mowpriya Das、Maximilian Niehues、Malte L. Schrader、Christian Gutheil、Bart Jan Ravoo、Frank Glorius
DOI:10.1002/anie.202016268
日期:2021.4.6
Hydroarylation is an effective strategy to rapidly increase the complexity of organic structures by transforming flat alkene moieties into three‐dimensional frameworks. Many strategies have already been developed to achieve the hydroarylation of styrenes, however most of these reports examine the hydroarylation of unpolar, β‐mono‐ or β‐unsubstituted styrenes, while exploring mainly electron‐rich benzene
作者:Gino Occhialini、Vignesh Palani、Alison E. Wendlandt
DOI:10.1021/jacs.1c12043
日期:2022.1.12
The positional isomerization of C═C double bonds is a powerful strategy for the interconversion of alkene regioisomers. However, existing methods provide access to thermodynamically more stable isomers from less stable starting materials. Here, we report the discovery of a dual catalyst system that promotes contra-thermodynamic positional alkeneisomerization under photochemical irradiation, providing
The enereaction of N-Phenyl-1,2,4-triazoline-3,5-dione with alkenes shows a remarkable preference for hydrogen abstraction from the group which is geminal to the larger substituent of the double bond. These results require that the dominant effect in the transition state of the enereaction is the nonbonded interactions.