1,3-Dipolar cycloaddition of N-substituted dipolarophiles and nitrones: highly efficient solvent-free reaction.
New isoxazolidines were synthesized in good to excellent yields by 1,3-dipolar cycloaddition of N-vinylamide dipolarophiles and nitrones. Strikingly, solvent-free conditions gave high conversion and yields, shortened reaction time, and minimized degradation products. N-Vinyloxazolidin-2-one and its analogues used in these cycloaddition reactions were conveniently prepared in excellent yields by a modified version of Buchwald's one-step copper-catalyzed vinylation using vinyl bromide. From the adducts, a two-step access to various unsymmetric aspartate derivatives was also described.
Nguyen
Thanh Binh
TB
UCO2M 6011 CNRS, Université du Maine, 72085, Le Mans, France.
Martel
Arnaud
A
Dhal
Robert
R
Dujardin
Gilles
G