Intramolecular cyclization reactions of arylpropargyl amides of electron-deficient α,β-alkenyl carboxylates and related compounds
Intramolecular cyclization reactions of arylpropargyl amides of electron-deficient α,β-alkenyl carboxylates and related compounds
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缺电子α,β-链烯基羧酸酯及相关化合物的芳基炔丙基酰胺的分子内环化反应
DOI：
10.1039/d3ob00129f
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发表时间：
2023
影响因子：
3.2
通讯作者：
Ogawa Akiya
中科院分区：
文献类型：
--
作者：
Wang Zhichao;Yamazaki Shoko;Morimoto Tsumoru;Takashima Hiroshi;Nakaoku Ayane;Shimizu Makoto;Ogawa Akiya
研究了缺电子α，β-烯基羧酸酯如异戊二酸酯和乙烯三羧酸酯的芳基炔丙基酰胺的分子内环化反应。在空气下，在二甲苯中，在140 °C下，将N-异吲哚酰胺与碱Et 3 N或DBU反应，得到苯并[f]异吲哚啉衍生物，产率为21-63%。苯并[f]异吲哚啉可以通过形成丙二烯中间体、分子内Diels-Alder反应、质子转移和氧脱氢来制备。合适的碱和产物产率取决于苯环上的取代基。另一方面，通过在DMSO中加热使富马酸酯和乙烯三羧酸酯的酰胺反应，得到作为主要产物的芳酰基取代的吡咯烷衍生物，这可能是通过在无金属条件下加入水实现的。此外，还研究了H和Me取代的炔衍生物的环化反应以进行比较。不同的炔取代基和反应条件下，可以选择性地生成不同类型的产物，如2-（1-苄基-4-甲酰基-2-氧代吡咯烷-3-基）乙酸乙酯和2-（1-苄基-2-氧代-4-亚乙烯基吡咯烷-3-基）丙二酸二乙酯.采用密度泛函理论（DFT）计算方法对反应机理进行了讨论。
Intramolecular cyclization reactions of arylpropargyl amides of electron-deficient α,β-alkenyl carboxylates such as fumarates and ethenetricarboxylates were investigated. The reaction of the fumaramides with a base, Et3N or DBU in xylenes at 140 °C under air gave benz[f]isoindoline derivatives in 21–63% yields. The benz[f]isoindolines may be produced via the formation of an allenic intermediate, intramolecular Diels–Alder reaction, proton transfer, and dehydrogenation by oxygen. The suitable bases and the product yields depend on the substituents on the benzene ring. On the other hand, the reaction of the amides of fumarate and ethenetricarboxylate by heating in DMSO gave aroyl-substituted pyrrolidine derivatives as major products, probably via addition of water under metal-free conditions. Furthermore, cyclization reactions of H and Me substituted alkyne derivatives were investigated for comparison. The selective formation of various types of products, such as ethyl 2-(1-benzyl-4-formyl-2-oxopyrrolidin-3-yl)acetate and diethyl 2-(1-benzyl-2-oxo-4-vinylidenepyrrolidin-3-yl)malonate, was found, depending upon the alkyne substituents and the reaction conditions. The reaction mechanisms have been discussed using density functional theory (DFT) calculations.