Activating Imides with Triflic Acid: A General Intramolecular Aldol Condensation Strategy Toward Indolizidine, Quinolizidine, and Valmerin Alkaloids

Author(s)

Quevedo-Acosta, Yovanny ^{[1, 2]} ; Jurberg, Igor D. ^[1] ; Gamba-Sanchez, Diego ^[2]

Affiliation

^[1] Univ Estadual Campinas, Inst Chem, Rua Monteiro Lobato 270, BR-13083862 Campinas, SP - Brazil

^[2] Univ Los Andes, Chem Dept, Lab Organ Synth Bio & Organocatalysis, Cra 1 18A-12 Q305, Bogota 111711 - Colombia

• Document type: Journal article
• Source: ORGANIC LETTERS; v. 22, n. 1, p. 239-243, JAN 3 2020.
• Web of Science Citations: 5

Abstract

A simple, inexpensive, step economic, and highly modular synthetic strategy to access izidine alkaloids is described. The key step is a TfOH-promoted intramolecular aldol condensation between enol and cyclic imide moieties. This cyclization strategy can be employed within an aza-Robinson annulation framework and represents a general tool to build fused bicyclic amines. To illustrate the power of this method, we describe the preparation of (+/-)-coniceine, (+/-)-quinolizidine, (+/-)-tashiromine, (+/-)-epilupinine, and the core of (+/-)-valmerins (AU)

• FAPESP's process: 17/24017-0 - Application of Isoxazolones in Organic Synthesis
• Grantee: Igor Dias Jurberg
• Support Opportunities: Regular Research Grants