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通过光反氧化拉塞米化实现的6π电循环

Sebastijan Ričko^1,2, René Slot Bitsch¹, Mikk Kaasik¹

¹Department of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark.

Journal of the American Chemical Society

|September 27, 2023

概括

这项研究引入了一种新型的催化方法,用于从racemic glycinates中制造奇拉. 一个双催化剂系统,结合光氧和易斯酸催化,通过oxa-6π电循环实现了酶融合合成.

科学领域:

有机化学
催化剂
不对称的合成

背景情况:

基拉尔2H-1,3-素是有价值的异环化合物.
开发针对这些结构的合成方法仍然是一个挑战.

研究的目的:

开发一种新型的以光电还原技术为基础的催化策略,用于合成性2H-1,3-素.
在一个前所未有的oxa-6π电循环中使用racemicα-substituted glycinates作为基质.

主要方法:

使用基于的化酸催化剂.
在可见光照射下使用商用光催化剂.
使用光学纯的α-化基质进行机械学研究和线性自由能量关系分析.

主要成果:

热反应选择性地将 (S) 配置的甘氨酸转化为富含的2H-1,3-素 (高达96:4 e.r. ) 的情况.
在可见光照射下添加光催化剂使一个反融合过程成为可能.
机理学研究显示出一种类特异性动态同位素效应,并证实了立体决定性6π电循环步骤.

结论:

建立了一种新型的双催化系统,结合了光和利性易斯酸催化,用于利性2H-1,3-佐的合成.
光催化剂有助于动态化体的相互转化,而化易斯酸则选择性地与 (S) 化体反应.
这些发现为具有机理性的催化循环提供了有价值的性异环新途径.

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