title: Brønsted acid assisted regio- and enantioselective direct O-nitroso aldol reaction catalysed by alpha,alpha-diphenylprolinol trimethylsilyl ether.
abstract: In the presence of p-nitrobenzoic acid, the O-nitroso aldol reaction of nitrosobenzene with enolisable aldehydes may be promoted by commercially available alpha,alpha-diphenylprolinol trimethylsilyl ether. The reaction proceeds with good yields and essentially complete enantioselectivity, with catalyst loadings in the 5-10 mol % range. The resulting alpha-oxyaldehyde adducts may be transformed in situ into alpha-oxyimines, which provide 1,2-amino alcohols upon treatment with Grignard reagents, in good overall yield (45-59%) and with typical diastereomeric ratios > or = 95:5.
authors.affiliation: Departamento de Química Orgánica I, Universidad del País Vasco, Manuel Lardizabal 3, 20018 San Sebastián, Spain.
authors.forename: Antonia
authors.initials: A
authors.lastname: Mielgo
authors.forename: Irene
authors.initials: I
authors.lastname: Velilla
authors.forename: Enrique
authors.initials: E
authors.lastname: Gómez-Bengoa
authors.forename: Claudio
authors.initials: C
authors.lastname: Palomo