Investigation of the mechanisms of ene reactions of carbonyl enophiles by intermolecular and intramolecular hydrogen-deuterium isotope effects: partitioning of reaction intermediates
作者:Zhiguo Song、Peter Beak
DOI:10.1021/ja00178a042
日期:1990.10
concerted mechanism for each reaction. In the ene reactions of 1 with 8 catalyzed by tin tetrachloride and of 1 with acetylium hexachloroantimonate, both the intermolecular and intramolecular isotope effects are small, results that are inconsistent with either a stepwise reaction via an equilibrating intermediate or a concerted mechanism. The ene reaction of 2 with acetic anhydride catalyzed by zinc chloride
已通过测定分子间和分子内氢-氘同位素效应研究了所选羰基亲烯体与亚甲基环己烷 (1) 和 1-亚甲基四氢萘 (2) 的 ene 反应机制。在 1 与二氧代琥珀酸二甲酯和 1 与氧代丙二酸二乙酯 (8) 的热烯反应中,两种同位素效应都是主要的和实质性的,与每个反应的协同机制一致。在四氯化锡催化的 1 与 8 和 1 与六氯锑酸乙炔的 ene 反应中,分子间和分子内同位素效应都很小,结果与通过平衡中间体或协同机制的逐步反应不一致。