Metal-catalyzed transformations of propargylic alcohols into alpha,beta-unsaturated carbonyl compounds: from the Meyer-Schuster and Rupe rearrangements to redox isomerizations.
The catalytic isomerization of propargylic alcohols promoted by transition-metals represents a straightforward and appealing route to synthetically useful alpha,beta-unsaturated carbonyl compounds. Three different reaction pathways are known for these atom-economical transformations: (i) the so-called Meyer-Schuster and Rupe rearrangements, in which a formal 1,3- or 1,2-shift of the hydroxyl group takes place, and (ii) the redox-type isomerization, which involves a simultaneous oxidation of the alcohol unit and reduction of the C[triple bond]C bond. In this Perspective article an overview of the different metal catalysts presently available to promote these isomerization reactions, their mechanisms of action as well as relevant synthetic applications, is provided.
Cadierno
Victorio
V
Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica Enrique Moles (Unidad Asociada al CSIC), Universidad de Oviedo, Julián Clavería 8, 33006, Oviedo, Spain. vcm@uniovi.es
Crochet
Pascale
P
García-Garrido
Sergio E
SE
Gimeno
José
J