甲基替代的亚齐里丁和亚齐蒂丁作为掩盖的1,3-和1,4-二极体,用于正式的 [3 + 2] 和 [4 + 2] 循环添加反应
Veejendra K Yadav1, Vardhineedi Sriramurthy
1Department of Chemistry, Indian Institute of Technology, Kanpur 208 016, India. vijendra@iitk.ac.in
Journal of the American Chemical Society
|November 25, 2005
概括
这项研究详细介绍了西替代亚齐里丁和亚齐蒂丁与亚烯和碳烯的新型反应,产生有价值的异环化合物. 组有效地指导了反应结果和立体化学.
科学领域:
- 有机化学 有机化学
- 异环化学 异环化学
- 有机化学 有机化学
背景情况:
- 亚齐里丁和亚齐蒂丁是含有的紧张型异环,具有多种合成应用.
- 在这些异环环开放反应中控制区域选择性和立体化学仍然是一个合成挑战.
- 在药物和材料化学中,开发新的合成方法来获取复杂的化合物至关重要.
研究的目的:
- 为了研究2 - 三-丁二四甲基替代亚齐里丁和亚齐蒂丁与各种电友基质的反应性.
- 探索三二四甲基组在控制这些反应的立体化学和区域化学结果方面的潜力.
- 为了证明这些替代性亚齐丁丁在合成复杂的异环基架,包括pyrrolidines中的实用性.
主要方法:
- 合成2-三-丁基基甲基替代亚齐里丁和亚齐蒂丁前体.
- 在易斯酸催化下,亚齐里丁和亚齐蒂丁衍生物与尼特利和碳化合物的反应 (例如,BF3·Et2O).
- 使用光谱技术 (例如NMR,质谱) 分析反应产品以确定结构和立体化学.
主要成果:
- 从替代亚齐里丁和亚齐蒂丁与烯酸和碳酸的反应中高效合成伊米达佐林,奥克萨佐利丁和四胺基衍生物.
- 通过易斯酸介导,将阿兹提丁重新排列为罗利丁骨架,涉及迁移.
- 证明 tert-butyldiphenylsilylmethyl 组决定了环切割的区域选择性和产生的产品的相对立体化学.
结论:
- 2 - 二二四甲基替代剂作为一个强大的指导组在亚齐里丁和亚齐蒂丁的反应性.
- 这种方法提供了一条通往功能化的伊米达,奥克萨索利丁,四胺和罗利丁系统的多功能途径.
- 基组的潜在CH2OH功能在异环化学中提供了独特的合成控制.
相关概念视频
E1 Reaction: Stereochemistry and Regiochemistry
One of the critical aspects of the E1 reaction mechanism, as also observed in E2, is the regiochemistry, with multiple regioisomers obtained as products. In the example discussed, the presence of water as a weak base favors elimination over substitution to generate two alkenes. Given that alkenes’ stability increases with the number of alkyl groups across the double bond, typically, E1 reactions lead to the Zaitsev product, for this is more substituted and stable than the Hofmann product.
Cycloaddition Reactions: Overview
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.
Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene
Electrophilic addition of halogens to alkenes proceeds via a cyclic halonium ion to form a 1,2-dihalide or a vicinal dihalide.
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.

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