ROLE OF 2-NAPHTHYL ETHER INTERMEDIATE IN FORMATION OF ISOLABLE ATROPISOMERS DERIVED FROM THE COUPLING REACTION OF (2-HYDROXY-3,3-DIMETHYLINDOLIN-1-YL)-(SUBSTITUTED PHENYL)METHANONES WITH 2-NAPHTHOL

摘要

The formation pathway of the atropisomers derived from the reaction of (2-hydroxy-3,3-dimethylindolin-1-yl)(4-substituted phenyl)methanones with 2-naphthol in the presence of BF3·Et2O was discussed on the basis of the isolation of the 2-naphthyl ether intermediate whose structure was determined by single crystal X-ray analysis. The results indicate that the coupling reaction proceeds through stepwise mechanism, i.e., the ether intermediate formation followed by Fries-type rearrangement.