Related Experiment Video
Updated: Aug 29, 2026

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyl(tropone)iron
Published on: August 12, 2019
Iron-catalyzed [1+1+1] cyclopropanation by sequential coupling of an ester to two carbenes
Lingran Kong1, Kevin Zong1,2, Marcus Hopfengärtner3
1Department of Chemistry, Scripps Research, La Jolla, CA, USA.
Abstract:
Traditional precious metal catalysis benefits from well-characterized inner-sphere elementary steps in which a single complex binds and unites substrates at the metal center. By contrast, base metal catalysts have recently demonstrated competence in cross-coupling transformations through iterative outer-sphere reactions in which product bond formation occurs by serial additions to the ligand, not the metal. Despite the emerging diversity of two-component outer-sphere reactions, comparable multicomponent outer-sphere couplings remain rare. In this study, we describe an iron-catalyzed [1+1+1] synthesis of cyclopropanols through iterative outer-sphere reactions between two carbenes and an ester. This reaction initially generates silyl enol ethers stereo-, regio-, and chemoselectively through a traceless, directed olefination that can be further exploited to enable transformations unavailable to prior methods.
Related Concept Videos
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Intramolecular Claisen Condensation of Dicarboxylic Esters: Dieckmann Cyclization
Cycloaddition Reactions: Overview
β-Dicarbonyl Compounds via Crossed Claisen Condensations
Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction
α-Hydroxy Ketones via Reductive Coupling of Esters: Acyloin Condensation Overview

