Pd催化氧化反应:增加催化剂寿命的策略
Wilson C Ho1, Kevin Chung1,2, Andrew J Ingram1,3
1Department of Chemistry, Stanford University , Stanford, California 94305, United States.
Journal of the American Chemical Society
|December 16, 2017
概括
一个催化剂前体有效氧化酒精和碳水化合物使用空气作为氧化剂. 开发了增强催化剂稳定性和效率的策略,使低负载有氧化成为可能.
科学领域:
- 催化剂
- 有机化学
- 绿色化学
背景情况:
- 复合物是醇氧化的有效催化剂.
- 使用空气作为终端氧化剂的有氧氧化是可取的,但面临着催化剂稳定性的挑战.
- 氧化降解联体,如新库,需要高的催化剂负载.
研究的目的:
- 开发用于提高有氧氧化催化剂前体的寿命和效率的策略.
- 了解有氧氧化过程中催化剂失活的机制.
- 为了使酒精,多和碳水化合物的高效氧化具有低负载.
主要方法:
- 复合物的合成和应用[(新古) Pd(μ-OAc) ]2[OTf]2.
- 调查催化剂失活路径的机制研究,包括激素自氧化.
- 实施连接物修改和添加牺牲性原子供体或基质清除剂.
- 优化各种基质的有氧氧化反应条件.
主要成果:
- 复合物是选择性氧化酒精,二醇,多醇和碳水化合物的有效催化剂前体.
- 氧化过程最初是通过激素自氧化机制降解新库连体而受到限制的.
- 连接物修改,添加牺牲性H原子捐赠物 (例如氧化) 或 styrene 显著改善了催化剂寿命和周转量 (TON).
- 用小于0.25mol%的Pd负载实现了聚醇的制剂规模有氧氧化.
结论:
- 开发的策略有效地提高了有氧氧化催化剂的寿命和效率.
- 了解禁用机制对于设计改进的催化系统至关重要.
- 这项工作在低负荷有氧氧化催化中取得了重大进展,特别是对于多和碳水化合物.
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