Oxidative Biaryl Coupling Reaction of Phenol Ether Derivatives Using a Hypervalent Iodine(III) Reagent

The hypervalent iodine(III)-induced intramolecular biaryl coupling reaction of phenol ether derivatives (nonphenolic derivatives) was investigated with the aim of preparing various dibenzo heterocyclic compounds. 1,3-Diarylpropanes ( 1a − e ), N -benzyl- N -phenethylamines ( 2a − c ) and N,N -dibenzylamines ( 3a − e ) react with a hypervalent iodine reagent, phenyliodine(III) bis(trifluoroacetate) (PIFA), containing BF 3 ·Et 2 O in CH 2 Cl 2 to give the biaryl coupling products ( 4 − 6 ) in good yield. As an application of the reaction, we examined the synthesis of oxygen- and sulfur-containing dibenzoheterocyclic compounds ( 12 − 15 ), whose side chain moiety could be easily cleaved by the known method to give 2,2‘-substituted biphenyl compounds ( 16 − 18 ).