Carbonyl olefin metathesis

It is a powerful method in organic synthesis using simple carbonyls and olefins and converting them into less accessible products with higher structural complexity.

In Lei's total synthesis of Huperzine Q,[4] they have furnished the cyclopentene ring through carbonyl-olefin metathesis using Schrock molybdenum alkylidene complex.

[7] A detailed mechanism for this metathesis process is described below: the catalytic cycle started with the condensation of aldehyde R1CHO with hydrazine catalyst, and then the reactive intermediate underwent cycloaddition with cyclopropene.

[9][10][11] As for intermolecular version, Bickelhaupt and co-workers have observed carbonyl-olefin metathesis product in 15-30% yield from treating benzaldehyde and alkenes upon EPZ-10, a solid Lewis acid.

[13][14] They found that trityl cation catalyst could promote formal cross metathesis between trisubstituted alkenes and arenecarbaldehydes to give β-alkylstyrene and acetone.