Premium
A Stereoselective and Practical Synthesis of ( E )‐α,β‐Unsaturated Ketones from Aldehydes
Author(s) -
Balducci Evita,
Attolino Emanuele,
Taddei Maurizio
Publication year - 2011
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201001182
Subject(s) - chemistry , knoevenagel condensation , stereoselectivity , reagent , atom economy , organocatalysis , organic chemistry , reaction conditions , aldehyde , hydroformylation , catalysis , enantioselective synthesis , rhodium
α,β‐Unsaturated ketones can be prepared by reaction of differently substituted β‐keto acids and aldehydes. The reaction is carried out under organocatalysis (β‐alanine, 0.5 equiv.) and generates the enones with high E selectivity (>95 %). This version of the Verley–Doebner modification of the Knoevenagel reaction is a practical alternative to the classic Horner–Wadsworth–Emmons (HWE) reaction without the formation of high molecular weight byproducts. The process makes use of simple reagents and can be applied to large‐scale synthesis under conditions compatible with atom‐economy principles. Differently substituted aliphatic, aromatic, or heteroaromatic α,β‐unsaturated ketones can be prepared. An example of a hydroformylation/Verley–Doebner Knoevenagel telescoped process is also described.