Proximity Effects. XXXII. Ring Opening of cis- and trans-Cycloöctene Oxide in Alumina-catalyzed and Uncatalyzed Pyrolysis and in Reaction with Magnesium Bromide Etherate
A Redox Strategy for Light-Driven, Out-of-Equilibrium Isomerizations and Application to Catalytic C–C Bond Cleavage Reactions
作者:Eisuke Ota、Huaiju Wang、Nils Lennart Frye、Robert R. Knowles
DOI:10.1021/jacs.8b12552
日期:2019.1.30
We report a general protocol for the light-driven isomerization of cyclic aliphatic alcohols to linear carbonyl compounds. These reactions proceed via proton-coupled electron-transfer activation of alcohol O-H bonds followed by subsequent C-C β-scission of the resulting alkoxy radical intermediates. In many cases, these redox-neutral isomerizations proceed in opposition to a significant energetic gradient
我们报告了光驱动的环状脂肪醇异构化为线性羰基化合物的通用协议。这些反应通过醇 OH 键的质子耦合电子转移活化进行,随后生成的烷氧基自由基中间体的 CC β 断裂。在许多情况下,这些氧化还原中性异构化与显着的能量梯度相反,产生的产品热力学稳定性低于起始材料。提出了一种机制来合理化这种不平衡行为,该机制可以作为设计由激发态氧化还原事件驱动的其他逆热力学转换的模型。
A crystalline, internally-coordinated chloroborane for asymmetric hydroboration
作者:Breanna von Dollen、John L. Wood、Quentin R. Savage、Andrew J. Jones、Charles M. Garner
DOI:10.1016/j.tet.2022.132654
日期:2022.2
Asymmetric hydroboration is an important method in the preparation of enantiomerically-enriched compounds that are necessary in many areas of chemistry. Here is reported the preparation of a unique chiral chloroborane-internal ether complex and its applications in asymmetric hydroboration. This chloroborane is easily obtained in crystalline, solvent-free and enantiomerically pure form. The chemical
不对称硼氢化是制备对映体富集化合物的重要方法,在许多化学领域都是必需的。本文报道了一种独特的手性氯硼烷-内醚配合物的制备及其在不对称硼氢化中的应用。这种氯硼烷很容易以结晶、无溶剂和对映体纯的形式获得。路易斯碱性甲氧基的化学位移对硼环境敏感,这使得该试剂特别适用于核磁共振研究,其中非对映异构体比例在许多情况下可以在氧化之前确定,甚至动力学也相对容易进行。它很容易与前手性烯烃反应,氧化后产生高达 82% ee 的醇。二烷基氯硼烷中间体可以通过直接重结晶或作为空气稳定的乙醇胺络合物进行非对映体纯化,氧化后得到高达 99.8% ee 的醇。氯基很容易被氢化物取代原位,允许分子内不对称硼氢化和氘硼化,具有分子间硼氢化不能提供的高度区域化学控制。
HAUFE G., MONATSH. CHEM., 1979, 110, NO 1, 121-127
作者:HAUFE G.
DOI:——
日期:——
CHHATWAL, V. K.;GAUTAM, R. K.;SAHARIA, G. S., J. INST. CHEM., INDIA, 1983, 55, N 2, 55-57
作者:CHHATWAL, V. K.、GAUTAM, R. K.、SAHARIA, G. S.
DOI:——
日期:——
<b>Proximity Effects. XXXII. Ring Opening of <b><i>cis</i></b>- and <b><i>trans</i></b>-Cycloöctene Oxide in Alumina-catalyzed and Uncatalyzed Pyrolysis and in Reaction with Magnesium Bromide Etherate</b>