Catalytic Acceptorless Dehydrogenation of Aliphatic Alcohols
Catalytic Acceptorless Dehydrogenation of Aliphatic Alcohols
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DOI：
10.1021/jacs.0c00123
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发表时间：
2020-03-04
影响因子：
15
通讯作者：
Kanai, Motomu
中科院分区：
文献类型：
--
作者：
Fuse, Hiromu;Mitsunuma, Harunobu;Kanai, Motomu
我们开发了第一个受体的脂肪族仲醇脱氢酮在可见光照射下，在室温下，通过设计一个三元混合催化剂系统，包括光氧化还原催化剂，硫代磷酸有机催化剂，和镍催化剂。该反应通过三个主要步骤进行：氢原子从醇底物的α-C-H键转移到光氧化的有机催化剂的巯基，用镍催化剂拦截所产生的碳中心自由基，和β-氢化物消除。该反应在温和条件下以高产率进行，而不从各种醇（包括空间位阻醇、类固醇和药物衍生物）产生副产物（除了H-2气体）。该催化剂体系还促进了醛和醇通过半缩醛中间体的无受体交叉酯化反应。
We developed the first acceptorless dehydrogenation of aliphatic secondary alcohols to ketones under visible light irradiation at room temperature by devising a ternary hybrid catalyst system comprising a photoredox catalyst, a thiophosphate organocatalyst, and a nickel catalyst. The reaction proceeded through three main steps: hydrogen atom transfer from the alpha-C-H bond of an alcohol substrate to the thiyl radical of the photooxidized organocatalyst, interception of the generated carbon-centered radical with a nickel catalyst, and beta-hydride elimination. The reaction proceeded in high yield under mild conditions without producing side products (except H-2 gas) from various alcohols, including sterically hindered alcohols, a steroid, and a pharmaceutical derivative. This catalyst system also promoted acceptorless cross-dehydrogenative esterification from aldehydes and alcohols through hemiacetal intermediates.