Phenyliodine(III) bis(trifluoroacetate) (PIFA) can effect the
intramolecular oxidative coupling of substituted 4-hydroxyphenyl-N-phenylbenzamides. The transformations
could be realized in a catalytic manner by using iodobenzene as
catalyst and m-chloroperoxybenzoic
acid or urea˙H2O2 as terminal oxidant.
This reaction constitutes an efficient method for the synthesis
of spirooxindoles.
hypervalent iodine - oxidative coupling - phenolic
coupling - spirooxindoles - iodobenzene