Mechanisms of solvolytic elimination reactions of tertiary substrates: stereospecific 1,2-elimination reactions
作者:Qingshui Meng、Alf Thibblin
DOI:10.1039/a901296f
日期:——
suggested to occur via a carbocation ionpair in which the leaving chloride ion abstracts the β-hydron. Alternatively, the reaction may have an enforced uncoupled concerted mechanism in which water acts as the hydron-abstracting base. Also, solvolysis of 2-methyl-1-phenylcyclopentyl p-nitrobenzoate (8-PNB) yields the more stable alkene 10 by anti stereochemistry.
The carbonyl–olefin metathesis (COM) reaction is an attractive approach for the formation of a new carbon–carbon double bond from a carbonyl precursor. In principle, this reaction can be promoted by the activation of the carbonyl group with a Brønsted acid catalyst; however, it is often complicated as a result of unwanted side reactions under acidic conditions. Thus, there have been only a very few
羰基-烯烃复分解 (COM) 反应是从羰基前体形成新的碳-碳双键的一种有吸引力的方法。原则上,该反应可以通过用布朗斯台德酸催化剂活化羰基来促进;然而,由于在酸性条件下发生不希望的副反应,它通常很复杂。因此,只有极少数的布朗斯台德酸催化 COM 反应的例子,所有这些都需要专门设计的装置。在此,我们报告了一种新的实用均相布朗斯台德酸催化方案,该方案使用硝基甲烷(一种容易获得的溶剂)来促进分子内闭环 COM 反应。
Bauer, Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences, 1913, vol. 156, p. 1472