A new antiaromatic compound: 1,4-biphenylenequinone synthesis and trapping reactions: can a quinone unit stabilize the cyclobutadiene?

Kilic H., Balci M.

TETRAHEDRON, cilt.57, sa.49, ss.9889-9897, 2001 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 57 Sayı: 49
  • Basım Tarihi: 2001
  • Doi Numarası: 10.1016/s0040-4020(01)01008-0
  • Dergi Adı: TETRAHEDRON
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.9889-9897
  • Anahtar Kelimeler: biphenylenequinone, cyclobutadiene, singlet oxygen, Diels-Alder reactions, nucleus-independent chemical shifts values, BICYCLIC ENDOPEROXIDES, <4>ANNULENE SYSTEM, BIPHENYLENE
  • Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

The photooxygenation of 4a,8b-dihydrobiphenylene affords an endoperoxide. NEt3-catalyzed rearrangement of this endoperoxide gave the corresponding hydroxy enone, while the CoTPP-catalyzed rearrangement afforded a bisepoxide. MnO2 oxidation of hydroxy enol leads to 4a,8b-dihydrobiphenylene-1,4-dione. The NIBS bromination of this dione produces mono- and dibromides. NEt3-supported elimination of monobromide and zinc elimination of dibromide afforded the target compound, 1,4-biphenylenequinone, which was trapped as the dimer and cycloadducts with cyclopentadiene and anthracene, respectively. Furthermore, 1,4-biphenylenequinone was generated upon oxidation of biphenylene-1,4-diol with bis(trifluoroacetoxy)iodobenzene (PIFA). The stability and reactivity of the title compound is discussed. (C) 2001 Elsevier Science Ltd. Ail rights reserved.