超原子価ヨウ素試薬を用いるアルキニル化合物の酸化的環化反応

抄録

We have developed the transition metal-catalyzed intramolecular reactions of alkynyl compounds for novel and concise syntheses of heterocyclic compounds. From the progress of our study on the synthesis of heterocycles, we have recently demonstrated the metal-free formation of heterocyclic compounds through oxidative cycloisomerization of the alkynyl compounds using hypervalent iodine (III). Thus, phenyliodine(III) diacetate (PIDA) efficiently mediates the formation of 2,5-disubstituted oxazoles incorporated with acetoxy group through the oxidative cycloisomerization of propargylamide derivatives. The oxidative cycloisomerization of 2-propargyl 1,3-dicarbonyl compounds mediated by phenyliodine(III) bis(trifluoroacetate) (PIFA) or iodosobenzene leads to the selective synthesis of 4,5-disubstituted furfuryl alcohols or furfurals.