A copper-catalyzed [2 + 3] formal cyclization reaction between α-hydroxyl ketones and arylacetonitriles has been developed. The reaction outcome was ultimately dependent on the structure of the α-hydroxy ketones employed. Tertiary α-hydroxy ketones gave 3,4,5,5-tetrasubstituted butenolides as the sole products, while secondary α-hydroxy ketones furnished 2,4,5-trisubstituted oxazoles selectively. This
An efficient method for the direct preparation of high synthetic valuable a-hydroxycarbonyls is described. The simple and readily available I-2 or NBS was used as catalyst. DMSO acts as the oxidant, oxygen source, and solvent. A diverse range of tertiary Csp(3)-H bonds as well as more challenging secondary Csp(3)-H bonds could be hydroxylated in this transformation. The reaction is mild, less toxic and easy to perform.
SLIWA, HENRI;RANDRIA-RAHARIMANANA, CLARISSE;CORDONNIER, GUY, HETEROCYCLES, 31,(1990) N, C. 427-431
作者:SLIWA, HENRI、RANDRIA-RAHARIMANANA, CLARISSE、CORDONNIER, GUY