971-93-7Relevant articles and documents
Oxidative gold catalysis meets photochemistry - Synthesis of benzo[a]fluorenones from diynes
N?sel, Pascal,Moghimi, Setareh,Hendrich, Christoph,Haupt, Marten,Rudolph, Matthias,Rominger, Frank,Hashmia, A. Stephen K.
supporting information, p. 3755 - 3760 (2015/01/09)
Diynes bearing one terminal and one triarylmethylsubstituted alkyne were converted into complex benzofluorenone derivatives via a one-pot process involving a gold-catalyzed step followed by a photocyclization/oxidation. In the first step an Noxide was used to position-selectively generate an a-oxo carbenoid at the terminal alkyne which after a regioselective 1,6-carbene transfer along the tethered tritylalkyne and a subsequent aryl 1,2-shift furnished tetraphenylethylene-like derivatives. These intermediates were successfully transformed to fluorenones via oxidative photocyclization.
Stimuli responsive surfaces through recognition-mediated polymer modification
Xu, Hao,Norsten, Tyler B.,Uzun, Oktay,Jeoung, Eunhee,Rotello, Vincent M.
, p. 5157 - 5159 (2007/10/03)
Specific three-point hydrogen bonding between diamidopyridine (DAP) and thymine (Thy) was employed to reversibly anchor "brush-like" Tri-DAP end-functionalized polystyrene onto Thy-modified silica surfaces. The Royal Society of Chemistry 2005.
Phenylvinylogously Extended Triphenylmethylium Systems
Hellwinkel, Dieter,Fritsch, Helmut
, p. 2351 - 2360 (2007/10/02)
As isoconjugated models for (phenylazo)tritylium ions of type A the tritylium systems containing one to three styryl or phenylethynyl substituents have been investigated.In accordance with simple theoretical model considerations these ions have VIS absorptions at considerably longer wavelengths than tritylium ion itself.They also show the expected bathochromic band shifts in going from the singly branched (1, 4) to the doubly and triply branched systems 2, 3 and 5, 6 as well as the predicted bathochromic shifts for 4-methoxystyryl (1b-3b) and hypsochromic shifts for 4-( dimethylammoniostyryl)- and 4-(nitrostyryl)tritylium ions 1c-3c and 1d, respectively.For most of the newly prepared tritylium systems fully resolved NMR spectra were obtained, whose signal positions correlate very well with the charge distributions derived from the elementary conjugation model.For the 4,4'-(1,2-ethenediyl)bistritylium system 12, whose color resembles that of 4-styryltritylium ion 1a, only the resonance lines of the inner protons 3,β-H and carbons C-4,β show significant deviations from the corresponding signal positions of the reference systems 1a and tritylium (13). - Key Words: Chromophores, combined / Ethene, diphenyl- / Ethyne, diphenyl- / Phenylmethylium
