Synthesis 2019; 51(10): 2157-2170
DOI: 10.1055/s-0037-1611723
paper
© Georg Thieme Verlag Stuttgart · New York

Synthesis of 1-Azaspiro[4.5]deca-1,3-dienes from N-Propargylic β-Enaminones in Basic Medium

Eda Karadeniz
,
We thank the Türkiye Bilimsel ve Teknolojik Araştirma Kurumu (Scientific and Technological Research Council of Turkey, TUBITAK; Grant No. 114Z811) and the Orta Doğu Teknik Üniversitesi (Middle East Technical University, METU; Grant No. GAP-103-2018-2770) for financial support of this research.
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Publication History

Received: 24 November 2018

Accepted after revision: 11 January 2019

Publication Date:
18 February 2019 (online)


Dedicated to Prof. Dr. İlker Özkan on the occasion of his 70th birthday

Abstract

A facile, efficient and unprecedented method for the synthesis of spiro-2H-pyrroles is reported. When reacted with 1-ethynylcyclohexylamine, α,β-alkynic ketones produced cyclohexane-embedded N-propargylic β-enaminones, which in the presence of cesium carbonate underwent nucleophilic cyclization to afford 1-azaspiro[4.5]deca-1,3-diene derivatives in good to excellent yields. This cyclization was found to be general for a variety of cyclohexane-embedded N-propargylic β-enaminones and demonstrated good tolerance to a broad range of aliphatic, aromatic and heteroaromatic groups with electron-withdrawing and electron-donating substituents. The decoration of pyrrole compounds with a spiro framework may exhibit potential for the synthesis of molecules of pharmacological interest.

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