Related Experiment Video
Updated: Dec 2, 2025

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
[3 + 2]-Dipolar Cycloaddition of Aldehyde-Tethered Alkynamides and Trimethylsilyl Amino Esters: A Gateway to Uniquely
Anirban Ghoshal1,2, Anamika Yadav1,2, Ajay Kumar Srivastava1,2
1Division of Medicinal and Process Chemistry, CSIR-Central Drug Research Institute, Lucknow 226031, Uttar Pradesh, India.
Abstract:
An efficient method for the generation of uniquely functionalized pyrrolo-pyrrolizinones, pyrido-pyrrolizinones, and azepino-pyrrolizinones via [3 + 2]-dipolar cycloaddition is described. The method involves the synthesis of tethered alkynamides using Ugi condensation and oxidation that were subsequently subjected to a dipolar cycloaddition reaction with trimethylsilyl amino esters. Further transformations to demonstrate the utility of these scaffolds were also investigated.
Related Concept Videos
Cycloaddition Reactions: Overview
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Preparation of Alkynes: Alkylation Reaction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Cycloaddition Reactions: MO Requirements for Thermal Activation
Aldehydes and Ketones with Amines: Imine and Enamine Formation Overview

![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)