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由铜 (II) 和基基介导的酒精氧化机制
Bradford L Ryland1, Scott D McCann, Thomas C Brunold
1Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.
Journal of the American Chemical Society
|August 5, 2014
概括
使用TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl) 的铜催化剂可以有效地氧化酒精. 这项研究阐明了反应机制,揭示了一个关键的转移步骤和一种类似于Oppenauer的酒精氧化途径.
科学领域:
- 催化剂是一种催化剂.
- 有机化学 有机化学
- 计算化学计算化学
背景情况:
- 铜复合物与2.2'-双和TEMPO (2,2,6,6-四甲基-N-oxyl) 是有效的有氧酒精氧化催化剂.
- 精确的Cu ((II) /TEMPO介导的酒精氧化机制仍在争论中,提出了各种途径.
研究的目的:
- 使用TEMPO阐明铜催化有氧酒精氧化的机制.
- 用实验和计算方法区分拟议的机械路径.
- 为了协调文献中关于这种催化系统的相互矛盾的数据.
主要方法:
- 使用激素探头基质进行实验研究.
- 密度函数理论 (DFT) 的计算.
- 运动和机械分析.
主要成果:
- 实验证据表明,长寿命的基因不是氧化反应中的中间体.
- DFT计算显示,从Cu (II) - 氧化物转移到协调的氧化物种的原子转移在能量上比转移到自由氧化基更受青.
- 拟议的Oppenauer-like路径解释了观察到的酒精反应性趋势 (基与异基,初级与二级) 以及TEMPO和像ABNO (9-azabicyclo[3.3.1]nonane N-oxyl) 这样的双循环亚基之间的差异.
结论:
- 这项研究澄清了用TEMPO催化铜氧化有氧酒精氧化的机制.
- 特定的转移途径涉及协调的氧化物种被确定为关键.
- 这些发现协调了先前的实验和计算数据,建立了一个类似于Oppenauer的机制.
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