Oxymetalation or oxidative cyclization? mechanism of Pd-catalyzed annulation of enynones
Related Experiment Video
Updated: Oct 26, 2025

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Hao Ni1, Xiaoqian He, Kangbao Zhong
1School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing, 400030, P. R. China. lanyu@cqu.edu.cn ruopeng@cqu.edu.cn.
Abstract:
Enynones are powerful synthons for constructing furan derivatives in the presence of transition metal catalysts. Unlike the conventional intramolecular nucleophilic attack with the activation of coinage metals, we propose that enynones undergo an oxidative cyclization process with a Pd(0) species. The full catalytic cycle involves oxidative cyclization, isocyanide insertion, and reductive elimination, which was supported by DFT calculations. Geometric and electronic analyses confirmed the oxidative cyclization process, which proceeds via a Pd(ii) intermediate.
Related Concept Videos
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Preparation of Epoxides
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
Thermal and Photochemical Electrocyclic Reactions: Overview
Acid-Catalyzed Ring-Opening of Epoxides
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)