Readily available pyridine- and quinoline-N-oxides as new organocatalysts for the enantioselective allylation of aromatic aldehydes with allyl(trichloro)silane.
The straightforward synthesis of a series of enantiomerically pure pyridine- and quinoline-N-oxides and their use as new organocatalysts for the enantioselective allylation of aromatic aldehydes with allyl(trichloro)silane is reported. The catalysts were readily assembled by combining commercially available enantiopure diamines with heterocyclic carboxylic acid N-oxides. The obtained compounds showed moderate to good chemical efficiency (up to 73% chemical yield) and satisfactory stereoselectivity (up to 50% ee). Tentative models of stereoselection were proposed to account for the stereochemical outcome of the reaction and to explain how the structural features of the catalyst control the stereoselctivity.
Dipartimento di Chimica Organica e Industriale, Universita' di Milano, Milan, Italy.
Luca
L
Pignataro
Maurizio
M
Benaglia
Mauro
M
Cinquini
Franco
F
Cozzi
Giuseppe
G
Celentano