Related Experiment Video
Updated: Jul 27, 2025

Synthesis of Wavelength-shifting DNA Hybridization Probes by Using Photostable Cyanine Dyes
Published on: July 6, 2016
Formal [4 + 2] Cycloadditions of Maleimides on Duplex DNA
Kaleena Basran1, Anna Bujalska2, Ashkan Karimi1
1Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, Quebec H3A 0B8, Canada.
Abstract:
Near-quantitative DNA bioconjugation and detailed mechanistic investigations of reactions involving 5-(vinyl)-2'-deoxyuridine (VdU) and maleimides are reported. According to accelerated reaction rates in solvents with increasing polarity and trends in product stereochemistry, VdU-maleimide reactions proceed via a formal [4 + 2] stepwise cycloaddition. In contrast, 5-(1,3-butadienyl)-2'-deoxyuridine (BDdU) reacts with maleimides in a concerted [4 + 2] Diels-Alder cycloaddition. VdU-maleimide reactions enable high-yielding bioconjugation of duplex DNA in vitro (>90%) as well as metabolic labeling experiments in cells.
Related Concept Videos
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Cycloaddition Reactions: Overview
Cycloaddition Reactions: MO Requirements for Thermal Activation
Maxam-Gilbert Sequencing
Challenges of the Maxam-Gilbert Method
The...
Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene
Cycloaddition Reactions: MO Requirements for Photochemical Activation

![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)