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,Ndibenzylamines (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).

The oxidative intramolecular phenolic coupling reaction of norbelladine derivatives (1) was investigated with the aim of preparing amaryllidaceae alkaloids. Spirodienone compounds (2), which are intermediates for the synthesis of an amaryllidaceae alkaloid, (+)-maritidine, or phenol ether derivatives containing the 5,6,7,8-tetrahydrobenzazocine systems (9), were selectively obtained by the reaction of 1 and the hypervalent iodine(III) reagent, phenyliodine(III) bis(trifluoroacetate) (PIFA). Both p − p‘ coupling (11) and p − o‘ coupling spirodienone compounds (12) were obtained by the reaction of phenol derivatives having an alkoxy group at the C-3‘ position (10) with PIFA.

By extending our oxidative phenol-coupling reactions using a hypervalent iodine(III) reagent, a versatile synthetic procedure for the galanthamine-type Amaryllidaceae alkaloids was accomplished. The first total synthesis of (±)-sanguinine and the total syntheses of (±)-galanthamine, (±)-narwedine, (±)-lycoramine, and (±)-norgalanthamine were also successfully carried out.

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