Mukaiyama aldol addition

Also known as: Mukaiyama aldol reaction

Schematic of the Mukaiyama aldol addition. Reagents: aldehyde, silyl enol ether, Lewis acid catalyst (TiCl4), aqueous work-up. Product: 1,3 ketol.

The Mukaiyama aldol addition is an organic reaction used to convert an aldehyde and a silyl enol ether to a 1,3 ketol using a Lewis acid catalyst (such as TiCl4), followed by aqueous work-up. The mechanism begins by coordination of the aldehyde's oxygen to Titanium, which activate the carbonyl for attack while also releasing a chloride ion. The chloride attacks the silicon of the silyl enol ether to form TMSCl and an enolate. The enolate then attacks the activated carbonyl and subsequent aqueous work-up provides the final 1,3 ketol product.[1][2]

Mechanism

Mechanism of the Mukaiyama aldol addition. Aqueous work-up.

References:

1.
Mukaiyama, T.; Narasaka, K.; Banno, K. Chem. Lett. 1973 1011–1014.
2.
Mukaiyama, T.; Banno, K.; Narasaka, K. J. Am. Chem. Soc. 1974, 96, 7503–7509.