One‐Pot Synthesis and Hydroxylaminolysis of Asymmetrical Acyclic Nitrones
摘要:
Aromatic aldehydes 1 were reductively aminated to the corresponding secondary amines 2 using NaBH4 in methanol in good yields. Amines 2 were oxidized with H2O2-WO42- regioselectively to nitrones 3, the structures of which were easily determined by reacting them with hydroxylamine hydrochloride as well as by spectral means. The products of hydroxylaminolysis in ether proved to be the corresponding benzaldehyde oximes 4 and benzyl or methyl hydroxylamine hydrochlorides 5.
Substituent control in the diastereoselectivity of dipolar cycloadditions of nitrones and their Zn(II) complexes with N-arylmaleimides
作者:Necdet Coşkun、Aylin Öztürk
DOI:10.1016/j.tet.2006.11.091
日期:2007.2
The nitrone ZnBr2 complexes react much more slowly than the free nitrone and the cycloaddition is exo selective in all cases independent of the substituents on the maleimide's aromatic ring. Thermal retrocycloaddition of the cycloadducts produce the corresponding nitrones. The ring opening in the presence of secondary amines did not induce imine formation. endo Adducts were shown for the first time to