The Aldol Reaction of Allenolates with Aldehydes in the Presence of Magnesium Diiodide (MgI2) as Catalyst
- Resource Type
- Article
- Authors
- Deng, Guang-Hui; Hu, Hui; Wei, Han-Xun; Paré, Paul W.
- Source
- Helvetica Chimica Acta; October 2003, Vol. 86 Issue: 10 p3510-3515, 6p
- Subject
- Language
- ISSN
- 0018019X; 15222675
Stereoselective synthesis of (Z)-α-(hydroxyalkyl)-β-iodoacrylates (=(2Z)-2-(hydroxyalkyl)-3-iodoprop-2-enoates) was achieved in a one-pot coupling reaction from methyl prop-2-ynoate, Me3SiI, and an alkanal under mild conditions with MgI2 as catalyst (→ 19; see Table and Scheme 1). Baylis-Hillman β-iodo adducts were generated in excellent yields with high (Z)-selectivity. The conversion of methyl prop-2-ynoate to an active methyl 3-iodo-1-[(trimethylsilyl)oxy]allenolate intermediate in situ followed by carbonyl addition is proposed as the reaction sequence (Schemes 1 and 2).