The Rhodium(II) Carbenoid Cyclization-Cycloaddition Cascade of α-Diazo Dihydroindolinones for the Synthesis of Novel Azapolycyclic Ring Systems

• Type of Material: Article
• Authors: Dylan B. England, Emory University; James M. Eagan, Emory University; Gokce Merey, Istanbul Technical University; Olcay Anac, Istanbul Technical University; Albert Padwa, Emory University
• Language: English
• Date: 2008-02-04
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2007 Elsevier Ltd. All rights reserved.
• License: Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.1016/j.tet.2007.10.038
• Title of Journal or Parent Work: Tetrahedron
• ISSN: 0040-4020
• Volume: 64
• Issue: 6
• Start Page: 988
• End Page: 1001
• Grant/Funding Information: We greatly appreciate the financial support provided by the National Institutes of Health (GM 059384) and the National Science Foundation (Grant CHE-0450779).
• Keywords: intramolecular; synthesis; dipolar cycloaddition; rhodium(II); α-diazo dihydroindolinones; carbenoid; azapentacycles
• Research Categories: Chemistry, General; Health Sciences, General

Abstract

Tandem carbonyl ylide formation-1,3-dipolar cycloaddition of α-diazo N-acetyl-tetrahydro-β-carbolin-1-one derivatives occur efficiently in the presence of a dirhodium catalyst to afford bimolecular cycloadducts in high yield. The Rh(II)-catalyzed reaction also takes place intramolecularly to give products derived from trapping of the carbonyl ylide dipole with a tethered alkene. The power of the intramolecular cascade sequence is that it rapidly assembles a pentacyclic ring system containing three new stereocenters and two adjacent quaternary centers stereospecifically in a single step and in high yield.