title: Hetero-Diels-Alder reactions of 2H-phospholes with aldehydes.
abstract: Transient 2-phenyl-3,4-dimethyl-5H-phosphole reacts at 150 degrees C with aldehydes RCH=O to give the corresponding [4 + 2] P-O cycloadducts with endo- (major) and exo-R-substituents. The cycloaddition with alpha,beta-unsaturated aldehydes takes place both at the C=O (major) and C=C bonds. Upon heating under reduced pressure, the benzaldehyde cycloadduct dissociates to give back the 2H-phosphole, which either dimerizes, is trapped by diphenylacetylene, or is deprotonated by (t)BuOK.
authors.affiliation: Laboratoire 'Hétéroéléments et Coordination' UMR CNRS 7653, DCPH, Ecole Polytechnique, 91128 Palaiseau Cedex, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Toullec
authors.forename: Louis
authors.initials: L
authors.lastname: Ricard
authors.forename: François
authors.initials: F
authors.lastname: Mathey