(Z)-alpha-haloacrylates: an exceptionally stereoselective preparation via Cr(II)-mediated olefination of aldehydes with trihaloacetates.
(Z)-alpha-Fluoro-, (Z)-alpha-chloro-, and (Z)-alpha-bromoacrylates were obtained with unprecedented yield and stereocontrol (>99%) via addition of the corresponding commercial trihaloacetates to aldehydes at room temperature using stoichiometric Cr(II) salts or catalytic Cr(II) with a regeneration system. The intermediate 2,2-dihalo-3-hydroxy adducts could be isolated in good yields under conditions of limited reagent at 0 degrees C.
Barma
D K
DK
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9038, USA.
Kundu
Abhijit
A
Zhang
Hongming
H
Mioskowski
Charles
C
Falck
J R
JR
D000085:Acetates / Q000737:chemistry*; D000179:Acrylates / Q000138:chemical synthesis*; D000447:Aldehydes / Q000737:chemistry*; D000475:Alkenes / Q000138:chemical synthesis*; D002857:Chromium / Q000737:chemistry*; D006846:Hydrocarbons, Halogenated / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D000085:Acetates; D000179:Acrylates; D000447:Aldehydes; D000475:Alkenes; D006846:Hydrocarbons, Halogenated; D002857:Chromium