1005481-98-0Relevant academic research and scientific papers
Efficient control of π-alkyne and vinylidene complex pathways for the W(CO)5(L)-catalyzed synthesis of two types of nitrogen-containing bicyclic compounds
Onizawa, Yuji,Kusama, Hiroyuki,Iwasawa, Nobuharu
, p. 802 - 803 (2008/09/20)
When ω-acetylenic dienol silyl ethers containing NMs part in the tether were treated with a catalytic amount of W(CO)6 under photoirradiation, 2-azabicyclo[3.3.0]octanes were obtained in good yield via π-alkyne complexes. On the other hand, treatment of the same substrates with a catalytic amount of W(CO)6 in the presence of n-Bu3N under the same reaction conditions gave 3-azabicyclo[3.3.0]octanes in good yield exclusively via vinylidene complexes. Thus, the π-alkyne and vinylidene complex pathways are easily controlled by using a catalytic amount of W(CO)5(L) and an amine. Copyright
Synthesis of 13C-dehydrocoelenterazine and NMR studies on the bioluminescence of a Symplectoteuthis model
Kuse, Masaki,Isobe, Minoru
, p. 2629 - 2639 (2007/10/03)
The bioluminescence of luminous squid (Symplectoteuthis oualaniensis) is presumed to be initiated by the addition of the sulfhydryl residue of a photoprotein to dehydrocoelenterazine (DCL). To clarify this step, a novel synthetic route was established to label DCL with 13C. Dithiothreitol (DTT) and glutathione (GSH) were used as photoprotein models. The addition of DTT and GSH to 13C-labeled DCL gave luminous chromophores. Its structures were confirmed by NMR and MS spectrometry. The DTT adduct emitted light under alkaline condition to produce an oxidized compound. Thus we succeeded in modeling the bioluminescence of a photoprotein with DTT. (C) 2000 Elsevier Science Ltd.
Synthesis of 13C-dehydrocoelenterazine and model studies on Symplectoteuthis squid bioluminescence.
Isobe,Kuse,Yasuda,Takahashi
, p. 2919 - 2924 (2007/10/03)
In the photoprotein of an Okinawan squid bioluminescence of Symplectoteuthis oualaniensis L a dehydrocoelenterazine has been assigned as a chromophoric precursor to its apoprotein. To prove this mechanism, we have established new synthetic route to ca. 100%-13C incorporated dehydrocoelenterazine and coelenterazine at the neighboring carbon of the 2-position of 2,3-dihydroimidazo-[1,2a]-pyrazinone skeleton. This 13C enriched dehydrocoelenterazine readily converted in equilibrium between its adduct forms as a diastereomixture with glutathione (GSH) or dithiothreitol (DTT) compounds having sulfhydryl group. Structures of such adducts were fixed under acidic conditions and then discussed by NMR spectroscopy as well as absorbance and fluorescence spectra.
