55077-79-7Relevant articles and documents
Studies in the cycloproparene series: Oxygen-containing 1H-cyclopropa[b]naphthalenes and their methylidene derivatives
Halton, Brian,Kay, Andrew J.,Zhi-mei, Zha,Boese, Roland,Haumann, Thomas
, p. 1445 - 1452 (1996)
3,6-Dimethoxy-1H-cyclopropa[b]naphthalene 4 is available from 1,4-benzoquinone in four steps in 27-28% overall yield. The diether 4 provides a range of methylidene derivatives 15a-e by way of the disilyl compound 14, and is efficiently demethylated by cerium(IV) ammonium nitrate to provide 1H-cyclopropa[b]naphthalene-3,6-dione 16 (85%) whose crystal structure is reported. Quinone 16 is the first stable cyclopropaquinone but it resists conversion into a 1-C exocyclic olefin. The chemistry of the compounds is described, their spectral data are discussed, and the cyclic voltammetry of 16 is provided.
Synthesis and luminescence of soluble meso-unsubstituted tetrabenzo- and tetranaphtho[2,3]porphyrins
Finikova, Olga S.,Cheprakov, Andrei V.,Vinogradov, Sergei A.
, p. 9562 - 9572 (2007/10/03)
Syntheses of soluble tetrabenzoporphyrins (TBP) and tetranaphtho[2,3] porphyrins (TNP), with multiple substituents in the conjugated aromatic rings but bearing no substituents in the meso-positions, is reported. Both types of porphyrins were obtained by direct aromatization of precursor porphyrins, annealed with either cyclohexene or dihydronaphthalene fragments. TBPs and TNPs possess powerful absorption bands in the near-infrared (λ = 610-710 nm, ε = 100,000-300,000 M-1 cm-1) and exhibit strong luminescence. Free bases and Zn complexes fluoresce with quantum yields of up to 50%, whereas Pd and Pt complexes phosphoresce in solutions at ambient temperatures. Remarkably, the phosphorescence quantum yields of Pd and Pt TBPs reach as high as 20-50%, which places them among the brightest near-infrared phosphors known to date.
Combined Multiple Claisen Rearrangement and Ring-closing Metathesis as a Route to Naphthalene, Anthracene, and Anthracycline Ring Systems
Chattopadhyay, Shital K.,Pal, Benoy K.,Maity, Susama
, p. 1190 - 1191 (2007/10/03)
A new route involving double Claisen rearrangement of a suitable 1,4-diallyloxyarene system followed by ring-closing metathesis of the resulting diene has been developed for the synthesis of various benzannulated cyclohexenes. An important demonstration of this methodology is the construction of the tetracyclic quinophenolic ring system of the clinically important anthracyclines.
