英国利物浦大学Jianliang Xiao团队报道了非血红素锰催化O2氧化裂解烯烃。相关研究成果发表在2021年6月23日出版的《美国化学会杂志》。

C═C双键氧化裂解与分子氧反应生成羰基化合物是化学和药物合成中的一个重要转变。在自然界中，含有第一行过渡金属的酶，特别是血红素和非血红素铁依赖酶，容易在环境条件下激活O2并氧化分解C═C键。然而，这一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大气压O2下氧化裂解烯烃，而已知的催化未活化烯烃裂解的催化剂很少。

该文中，研究人员描述了一个光驱动，锰催化的策略，用于在1 atm氧气下烯烃选择性氧化成羰基。在清洁、温和的条件下，利用第一行生物相关金属催化剂，芳香族和各种未活化的脂肪族烯烃首次被氧化得到酮和醛。此外，该策略表现出很好的功能群容忍度。机制研究表明，包括不对称，混合价双(μ-oxo）-Mn（III，IV）络合物的锰-oxo物种参与氧化，同时溶剂甲醇参与O2的活化，从而形成oxo物种。

附：英文原文

Title: Oxidative Cleavage of Alkenes by O2 with a Non-Heme Manganese Catalyst

Author: Zhiliang Huang, Renpeng Guan, Muralidharan Shanmugam, Elliot L. Bennett, Craig M. Robertson, Adam Brookfield, Eric J. L. McInnes, Jianliang Xiao

Issue&Volume: June 23, 2021

Abstract: The oxidative cleavage of C═C double bonds with molecular oxygen to produce carbonyl compounds is an important transformation in chemical and pharmaceutical synthesis. In nature, enzymes containing the first-row transition metals, particularly heme and non-heme iron-dependent enzymes, readily activate O2 and oxidatively cleave C═C bonds with exquisite precision under ambient conditions. The reaction remains challenging for synthetic chemists, however. There are only a small number of known synthetic metal catalysts that allow for the oxidative cleavage of alkenes at an atmospheric pressure of O2, with very few known to catalyze the cleavage of nonactivated alkenes. In this work, we describe a light-driven, Mn-catalyzed protocol for the selective oxidation of alkenes to carbonyls under 1 atm of O2. For the first time, aromatic as well as various nonactivated aliphatic alkenes could be oxidized to afford ketones and aldehydes under clean, mild conditions with a first row, biorelevant metal catalyst. Moreover, the protocol shows a very good functional group tolerance. Mechanistic investigation suggests that Mn–oxo species, including an asymmetric, mixed-valent bis(μ-oxo)-Mn(III,IV) complex, are involved in the oxidation, and the solvent methanol participates in O2 activation that leads to the formation of the oxo species.

DOI: 10.1021/jacs.1c05757

Source: https://pubs.acs.org/doi/10.1021/jacs.1c05757