氨基基的高度酶选择性催化循环化
Kuntal Manna1, William C Everett, George Schoendorff
1Department of Chemistry and U.S. Department of Energy Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA.
Journal of the American Chemical Society
|May 2, 2013
概括
基拉尔N-异环胺是通过使用新型4组复合物的氨基的催化循环合成的. 这种高度酶选择性的过程显示出协调的过渡状态,使得高效的非对称合成成为可能.
科学领域:
- 有机金属化学 有机金属化学
- 不对称的催化剂.
- 合成有机化学 合成有机化学
背景情况:
- 开发高效的催化方法来合成性N-异环胺对于制药和材料科学至关重要.
- 4组金属复合物与环二烯二 ((oxazolinyl) 酸连接物为催化提供独特的固体和电子特性.
研究的目的:
- 通过使用新型环二烯 (oxazolinyl) 酸盐4组复合物,研究氨基的催化循环.
- 阐明这种高度选性转换的机制,并确定关键的过渡状态特征.
主要方法:
- 在低温下使用,和复合物的各种氨基的催化循环.
- 机械学研究采用合成测试,运动分析,初级运动同位素效应和过渡状态理论.
- 立体化学分析以确定N-异环氨基胺产品的反体过量.
主要成果:
- 成功合成了五,六和七个成员的N-异环胺,具有高的反选择性 (>90%,高达99%).
- 动力学研究表明可逆的基质-催化剂相互作用,随后是不可逆的N-H键断裂阶段.
- 激活参数和动态同位素效应支持高度组织的,六中心的,协调的过渡状态.
结论:
- 开发的催化系统提供了一条高效的途径,以致于对抗聚合物丰富的N-异环胺.
- 机理学研究揭示了一个独特的协调过渡状态,负责高立体选择性.
- 这项研究提供了关于4组金属介导的不对称的胺化/循环化机制的宝贵见解.
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