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一个N,N'-二碳烯:研究C-H插入,可逆碳化和过渡金属协调化学
Todd W Hudnall1, Christopher W Bielawski
1Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA.
Journal of the American Chemical Society
|October 22, 2009
概括
一种新的N-异环碳素 (NHC) 被合成并证明了双重反应性. 这种碳素可逆地与一氧化碳结合,形成第一个二氧化二甲基,并形成复合物.
科学领域:
- 有机金属化学 有机金属化学
- 碳烯化学 碳烯化学
- 催化剂是一种催化剂.
背景情况:
- N-异环碳 (NHCs) 是有机金属化学中的多功能联体.
- 了解NHC反应性对于开发新的催化系统至关重要.
- 新型NHC结构的合成和表征扩大了它们的应用范围.
研究的目的:
- 合成一种具有独特结构特征的新型N-异环碳 (NHC).
- 研究合成的NHC的反应性,重点关注其电友和核友性质.
- 探索这种NHC在碳化反应和协调化学中的潜力.
主要方法:
- 使用二甲基马洛尼二化物和一种形式胺合成一种胺盐前体.
- 甲基盐的脱,生成自由的N-异环碳 (NHC) 1.
- NHC 1与三级C-H键,一氧化碳和前体 ([Ir(COD) Cl]2) 的反应.
主要成果:
- 甲盐 [1H][OTf]以高产率 (>99%) 进行合成.
- NHC 1成功生成并表现出特有的电友性碳烯反应性,包括C-H插入.
- 在温和条件下NHC 1可逆结合的一氧化碳,形成第一个二氧化,提供了详细的热力学参数.
- NHC 1也表现出核友性行为,形成一种与已知的NHC金属类型相似的复合物 (1-[Ir(COD) Cl)).
- 复合物与二氧化碳发生反应,形成碳复合物 (1-[Ir(CO) 2Cl]),其电子性质由红外光谱学特征.
结论:
- 合成了一种具有双电友和核友特性的新型N-异环碳 (NHC).
- NHC使一氧化碳的可逆固定成为可能,产生了第一个二氧化,突出了其在碳捕获和利用方面的潜力.
- 该NHC形成稳定的复合体,证明其作为协调化学和潜在的催化中的配体的实用性.
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