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Updated: Mar 6, 2026

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers
Published on: December 16, 2022
Altering the Cyclization Modes: Temperature-Dependent Intramolecular 7-Endo-Dig vs 6-Endo-Dig Electrophilic Ring
Maloy Nayak1, Young Kee Kang2, Ikyon Kim1
1College of Pharmacy and Yonsei Institute of Pharmaceutical Sciences, Yonsei University 85 Songdogwahak-ro, Yeonsu-gu, Incheon, 21983, Republic of Korea.
Abstract:
In an attempt to construct 10-acyl-5H-benzo[e]pyrrolo[1,2-a]azepines via acid-catalyzed intramolecular alkyne carbonyl metathesis, two distinctive modes of cyclization were revealed to depend on the reaction temperatures. 5H-Benzo[e]pyrrolo[1,2-a]azepine-1-carbaldehydes with a substituent at the C11 position were obtained as major products at 90 °C as a result of intramolecular 7-endo-dig cyclization, while 6-endo-dig ring closure by electrophilic addition of nitrogen of the pyrrole to a vinyl cation generated under acidic medium followed by an unprecedented domino rearrangement process was observed at 40 °C in some cases, resulting in 5-aryl-11H-benzo[d]pyrrolo[1,2-a]azepine-1-carbaldehydes along with the former products.
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