A Three-Step Synthesis of Tetrasubstituted NH-Pyrroles

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• 作者：Tristan A. Reekie ; Etienne J. Donckele ; Giorgio Manenti ; Salome Püntener ; Nils Trapp ; François Diederich
• 刊名：Organic Letters
• 出版年：2016
• 出版时间：May 6, 2016
• 年：2016
• 卷：18
• 期：9
• 页码：2252-2255
• 全文大小：353K
• 年卷期：0
• ISSN：1523-7052

文摘

Buta-1,3-dienes appended with electron-withdrawing groups (EWGs), derived from the [2 + 2] cycloaddition–retroelectrocyclization (CA–RE) cascade, react with (predominately) nitrogen-based nucleophiles affording tetrasubstituted 2-amino-NH-pyrroles in moderate to excellent yields with complete regioselectivity. Penta-2,4-dien-1-ones also undergo a similar transformation, providing analogous products and greatly enhancing the substitution of the pyrrole available. Oxidation from pyrrole to pyrrolidinone affords highly colored compounds that experience a strong bathochromic shift of the longest-wavelength absorption band in the UV/vis spectrum upon protonation, with return to the original spectra following neutralization.