Scholarlink

<p>Attaining the selective oxidation of isochroman into isochromanone in a molecular oxygen (O<sub>2</sub>) environment without any additives, via a heterogeneous oxidation process, is highly desirable and challenging work. Herein, we prepare two mixed-addendum polyoxometalate-based coordination polymers of the general formula [H<sub><i>x</i></sub>M<sub>1-<i>x</i></sub>(<i>i</i>-Pr-Im)<sub>4</sub>][H<sub>2</sub>N(CH<sub>3</sub>)<sub>2</sub>]<sub>4</sub>[HPMo<sub>8</sub>V<sub>6</sub>O<sub>42</sub>] (M = Co 1, Ni, 2; <i>i</i>-Pr-Im = 1-isopropyl-1H-imidazole). Needing no additives, they can catalyze the selective oxidation of isochroman to isochromanone with O<sub>2</sub> as an oxidant, with yields of 91.5% (1) and 46.8% (2), respectively. Mechanistic studies indicate that the excellent performance of catalyst 1 is attributed to the synergistic operation of [Co(<i>i</i>-Pr-Im)<sub>4</sub>)] complex and PMo<sub>8</sub>V<sub>6</sub> unit, and that the catalytic reaction is a radical pathway involving superoxide radicals. Additionally, the catalyst 1 can be recycled and reused at least four times with uncompromised performance. These results provide fundamental guidelines for designing efficient and multi-site heterogeneous catalysts for the selective oxidation of benzyl C(sp<sup>3</sup>)-H bonds by activating O<sub>2</sub>.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Additive-free oxidation of isochromans with molecular oxygen synergistically catalyzed by mixed-addendum polyoxometalate-based coordination polymers

  • 期刊论文

  • 发表日期：

    2025年2月28日

查看全文
  • Zou-Guang Han,
  • Ling-Ling Dai,
  • Hong-Rui Tian,
  • Xiang-Yu Ren,
  • Jie Lian,
  • Bao-Kuan Chen,
  • Yan-Feng Bi

摘要

Attaining the selective oxidation of isochroman into isochromanone in a molecular oxygen (O2) environment without any additives, via a heterogeneous oxidation process, is highly desirable and challenging work. Herein, we prepare two mixed-addendum polyoxometalate-based coordination polymers of the general formula [HxM1-x(i-Pr-Im)4][H2N(CH3)2]4[HPMo8V6O42] (M = Co 1, Ni, 2; i-Pr-Im = 1-isopropyl-1H-imidazole). Needing no additives, they can catalyze the selective oxidation of isochroman to isochromanone with O2 as an oxidant, with yields of 91.5% (1) and 46.8% (2), respectively. Mechanistic studies indicate that the excellent performance of catalyst 1 is attributed to the synergistic operation of [Co(i-Pr-Im)4)] complex and PMo8V6 unit, and that the catalytic reaction is a radical pathway involving superoxide radicals. Additionally, the catalyst 1 can be recycled and reused at least four times with uncompromised performance. These results provide fundamental guidelines for designing efficient and multi-site heterogeneous catalysts for the selective oxidation of benzyl C(sp3)-H bonds by activating O2.

Graphical Abstract