AuBr3-catalyzed [4 + 2] benzannulation between an enynal unit and enol

Naoki Asao, Haruo Aikawa, Yoshinori Yamamoto

    Research output: Contribution to journalArticlepeer-review

    258 Citations (Scopus)


    The reaction of enynals 1, including o-alkynylbenzaldehydes, and carbonyl compounds 2 in the presence of a catalytic amount of AuBr3 in 1,4-dioxane at 100 °C gave the functionalized aromatic compounds 3 in high yields. The AuBr3-catalyzed formal [4 + 2] benzannulation proceeds most probably through the coordination of the triple bond of 1 to AuBr3, the formation of a pyrylium auric ate complex via the nucleophilic addition of the carbonyl oxygen atom, the reverse electron demand-type Diels-Alder addition of the enols, derived from 2, to the auric ate complex, and subsequent dehydration and bond rearrangement. Similarly, the AuBr3-catalyzed reactions of 1 with acetal compounds afforded the corresponding aromatic compounds in good yields.

    Original languageEnglish
    Pages (from-to)7458-7459
    Number of pages2
    JournalJournal of the American Chemical Society
    Issue number24
    Publication statusPublished - 2004 Jun 23

    ASJC Scopus subject areas

    • Catalysis
    • Chemistry(all)
    • Biochemistry
    • Colloid and Surface Chemistry


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