One-pot four-component synthesis of pyrimidyl and pyrazolyl substituted azulenes by glyoxylation–decarbonylative alkynylation–cyclocondensation sequences

• Charlotte F. Gers,
• Julia Rosellen,
• Eugen Merkul and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1173–1181, doi:10.3762/bjoc.7.136

• -component approach to heterocyclic derivatives of azulene is well suited for the development of functional chromophores with extended π-conjugation. Selected resonance structures of azulene (1a) and structure of the sesquiterpene guaiazulene (1b). Synthesis of ynones by glyoxylation–decarbonylative

Conjugated polymers containing diketopyrrolopyrrole units in the main chain

• Bernd Tieke,
• A. Raman Rabindranath,
• Kai Zhang and
• Yu Zhu

Beilstein J. Org. Chem. 2010, 6, 830–845, doi:10.3762/bjoc.6.92

• monomer (Figure 4). The same coupling reaction of M-4 resulted in polymer P-22, its π-conjugation being interrupted at the N-lactam units. Consequently, the absorption and emission behaviour were not much different from the corresponding monomer, the band gaps of the two isomers being 2 and 2.3 eV