488-20-0Relevant academic research and scientific papers
Mechanism-based inactivation of coenzyme B12-dependent 2-methyleneglutarate mutase by (Z)-glutaconate and buta-1,3-diene-2,3- dicarboxylate
Buckel, Wolfgang,Pierik, Antonio J.,Plett, Sandra,Alhapel, Ashraf,Suarez, Diana,Tu, Shang-Min,Golding, Bernard T.
, p. 3622 - 3626 (2007/10/03)
In the presence of holo 2-methyleneglutarate mutase, buta-1,3-diene-2,3- dicarboxylate and (Z)-glutaconate [(Z)-pent-2-ene-1,5-dicarboxylate], but not (E)-glutaconate, each induced homolysis of the Co-C bond of coenzyme B 12 to afford cob(II)alamin and the 5′-deoxyadenosyl radical. The latter probably added to the double bond in (Z)-glutaconate and one of the double bonds in buta-1,3-diene-2,3-dicarboxylate to afford a corresponding "radical adduct". The formation of new radicals and cob(II)alamin was diagnosed by UV/Visible and EPR spectroscopy. (Z)-Glutaconate rapidly inactivated the mutase with formation of aquocobalamin, which was possibly derived by electron transfer from cob(II)alamin to the radical adduct. In contrast, buta-1,3-diene-2,3-dicarboxylate was a much slower inactivator. In this case, the spectroscopic data revealed a relatively stable complex of the radical adduct with cob(II)alamin in the active site of the enzyme. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
A facile synthesis of fulgenic acid via base induced 1,4- dehydrobromination of (bromomethyl)methylmaleic anhydride
Deshpande, Sachin G.,Argade, Narshinha P.
, p. 1306 - 1308 (2007/10/03)
A facile synthesis of fulgenic acid (1) via 1,4-dehydrobromination of (bromomethyl)methylmaleic anhydride (2) using aqueous KOH, t-BuOK in THF, and NaH in benzene in 60-85% yield is described. The newly synthesized (hydroxymethyl)methylmaleic anhydride (3) also underwent smooth 1,4- elimination in the presence of aqueous KOH to yield 1.
Reaction of Aryl and Vinyl Halides with Zerovalent Nickel-Preparative Aspects and the Synthesis of Alnusone
Semmelhack, M.F.,Helquist, Paul,Jones, L.D.,Keller, Leonard,Mendelson L.,et al.
, p. 6460 - 6471 (2007/10/02)
Zerovalent nickel complexes such as bis(1,5-cyclooctadiene)nickel and tetrakis(triphenylphosphine)nickel react rapidly with aryl and vinyl halides to produce the symmetrical coupling products, a low-temperature analogue of the Ullman reaction.The reaction proceeds through oxidative addition of the organic halide to Ni(0), and the reactivity of the Ni(II)intermediates has been examined.Arylnickel halide complexes decompose rapidly to biaryls in DMF.The coupling of simple vinyl halides proceeds with isomerization of the double bond but 3-haloacrylates give efficient co upling with retention of geometry.Cyclizations to form ortho-bridged biaryls are efficient in simple cases (6-, 7-, 8-, 9-, 10-, and 14-membered rings) but fail with an ortho-disubstituted case.The 13-membered meta-bridged cyclic biphenyl, alnusone, is prepared efficiently with the crucial aryl halide coupling to form the ring proceeding in 50percent yield.A side reaction promoted by the presence of protons and with certain ortho-substituted aryl halides is reduction of the aryl halide to the arene.This process can be enhanced by deliberate addition of acid during reaction with Ni(0) and a series of aryl halides underwent succesful reduction.
