Advanced Topic 842 of 1102 Organic Chemistry
Michael Addition
Conjugate addition of nucleophiles to alpha,beta-unsaturated carbonyls.
In-depth explanation of Michael Addition
The Michael addition is a conjugate addition in which a nucleophile adds to the beta carbon of an alpha, beta-unsaturated carbonyl compound, giving a 1,4 addition product. The electron-poor beta carbon is attacked by a soft nucleophile such as an enolate, an amine or a thiol. The enolate that forms is then protonated. This reaction forms carbon-carbon bonds under mild conditions and is widely used in organic synthesis. Biological thiols add to the same kind of unsaturated system in cell chemistry.
Going deeper: Michael Addition
Key ideas: Conjugate (1,4) addition of a stabilised enolate (from malonate, beta-keto ester or nitroalkane) to an alpha,beta-unsaturated carbonyl, forming a new C-C bond at the beta carbon. Soft nucleophiles (enolates, amines, thiols, cuprates) favour 1,4; hard nucleophiles (Grignard, organolithium, hydride) favour direct 1,2 addition. Combined with an aldol it makes Robinson annulation.
Common mistakes and connections: Students put the nucleophile on the carbonyl carbon (1,2) rather than the beta carbon. Another error is assuming Grignard reagents always give conjugate addition; Gilman cuprates do instead. Links to enolate chemistry, HSAB theory, thiol addition in biochemistry and ring-forming sequences.
Visualization of Michael Addition
A soft nucleophile adds to the beta carbon of an alpha,beta-unsaturated carbonyl, and the resulting enolate is protonated. The interactive lesson shows this as a live animation or chart.
Worked example and use case
The diethyl malonate anion adds to the beta carbon of methyl vinyl ketone in a Michael addition.
Frequently asked questions about Michael Addition
What is Michael Addition?
Conjugate addition of nucleophiles to alpha,beta-unsaturated carbonyls.
Is Michael Addition a beginner, intermediate or advanced topic?
Michael Addition is a advanced topic in Organic Chemistry. It builds on beginner and intermediate topics, so review those first if needed.
What should I learn before Michael Addition?
Study these earlier topics in Organic Chemistry first: Diels-Alder Reaction, Wittig Reaction, Claisen Condensation.
What comes after Michael Addition?
The next topics in Organic Chemistry are Pericyclic Reactions and Woodward-Hoffmann Rules.
Can I practise Michael Addition with quizzes?
Yes. The interactive lesson includes a self-check question on Michael Addition, and the Organic Chemistry quiz draws on every topic in this area.
Where Michael Addition fits in Organic Chemistry
Michael Addition is topic 114 of 148 in Organic Chemistry.