由和二胺介导的立体选择性乙醇化:在溶液和固态中形成对比的聚合行为
Xuyang He1, John F Allan, Bruce C Noll
1Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA.
Journal of the American Chemical Society
|May 12, 2005
概括
和 bis ((hexamethyldisilazide) 基在乙烯溶解的极性溶剂中显示Z-选择性. 然而,系统更喜欢在溶液中的E-酸盐,形成单体二元平衡.
科学领域:
- 有机金属化学 有机金属化学
- 立体选择性合成
- 酸的乙醇化是可以实现的.
背景情况:
- 双甲基 (甲基) 金属复合物是有力的基.
- 了解金属酸盐中间体对于立体选择性反应至关重要.
研究的目的:
- 为了评估和 bis ((hexamethyldisilazide) 对于立体选择性胺乙醇化.
- 阐明金属酸盐中间体的结构和电子特性.
主要方法:
- 烯与和 bis ((hexamethyldisilazide) 的反应.
- 在现场监测使用NMR光谱学.
- 实验中的Silyl enol 以太捕获实验.
- 对金属酸盐复合物的晶体分析.
主要成果:
- 这两种基都在极性溶剂中表现出Z-选择性.
- 系统在溶液中表现出E-酸盐的偏好,并观察到单体-二元平衡.
- 结晶学数据显示了一种溶解的胺乙烯酸二聚.
- 系统表现出明显的行为,形成溶剂分离的离子对和单氨酸乙酸盐.
结论:
- 溶剂和金属的选择显著影响金属乙烯酸盐的立体选择性和结构.
- 和二 ((hexamethyldisilazide) 提供可调节的反应性,用于乙醇化.
- 获得了对金属酸中间体的详细结构见解.
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