1.
Org Biomol Chem
; 11(38): 6520-5, 2013 Oct 14.
Artículo
en Inglés
| MEDLINE
| ID: mdl-23963094
RESUMEN
An efficient regio-, stereo- and chemo-specific synthesis of 1,3-benzoxazines via 6-exo-dig cyclization to afford the Z-isomer is reported. The structure and connectivity were confirmed unambiguously on the basis of (1)H NMR, NOESY, and ORTEP. Furthermore, DFT studies revealed that the Z-isomer was more stable than the E-isomer. Iodine substituted 1,3-benzoxazines were very useful precursors for cross coupling reactions. Suzuki reaction was carried out successfully and the resulting product was transformed to 1-(4-nitrobenzoyl)-2,2-diphenylindolin-3-one in the presence of a Lewis acid.