Synthesis of Functionalized Δ³-Pyrrolines via a Ag(I)-Catalyzed Cyclization of Amino Acid Derived Allenes

Branko Mitasev, Kay M. Brummond*

*Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA, Email: kbrummonpitt.edu

B. Mitasev, K. M. Brummond, Synlett, 2006, 3100-3104.

DOI: 10.1055/s-2006-949624

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Abstract

Synthesis of various highly functionalized Δ³-pyrrolines has been accomplished by a AgNO₃-catalyzed cyclization reaction of allenic amino acids that proceeds with transfer of chiral information. A new mode of cyclization of allenic benzoyl-protected amines in the Ag(I)-catalyzed reaction leading to oxazines was also observed.

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Details

The document details the synthesis of functionalized Δ³-pyrrolines via a silver(I)-catalyzed cyclization of amino acid-derived allenes. This method, part of a diversity-oriented synthesis (DOS) approach, leverages the unique reactivity of allenes to generate structurally diverse molecules. The process involves the cyclization of allenic amino acids, which can lead to various heterocyclic scaffolds, including oxazines and pyrrolines. The study highlights the use of AgNO₃ and AgBF₄ as catalysts, with the reactions proceeding with the transfer of chiral information from the starting materials. The resulting Δ³-pyrrolines are of significant interest due to their potential biological activity and utility as synthetic intermediates. The document also discusses the preparation of these compounds, including the removal of protecting groups and subsequent functionalization steps. The research underscores the versatility of the allene moiety in synthetic chemistry and aims to create a library of highly functionalized Δ³-pyrrolines for further biological testing. The work is supported by the National Institutes of Health and involves collaboration with the University of Pittsburgh Center for Chemical Methodologies and Library Development.

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Key Words

pyrrolines, allenes, cyclization, silver catalysis, amino acid, oxazines

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ID: J60-Y2006-4760