34918-77-9Relevant academic research and scientific papers
α-Imino Iridium Carbenes from Imidoyl Sulfoxonium Ylides: Application in the One-Step Synthesis of Indoles
Burtoloso, Antonio C. B.,Caiuby, Clarice A. D.,De Jesus, Matheus P.
, p. 7433 - 7445 (2020/06/27)
Imidoyl sulfoxonium ylides are presented for the first time as potential precursors to generate α-imino metal-carbene intermediates and applied in direct C-H functionalization reactions catalyzed by [Ir(cod)Cl]2 (4 mol %) to provide 2-substituted indoles (up to 70% yield) in just one step. This class of sulfur ylide is successfully obtained from imidoyl chloride and dimethylsulfoxonium methylide (23 new examples in 45-85% yield) or by imino group formation from the corresponding β-keto sulfoxonium ylides and anilines in the presence of TiCl4 as a Lewis acid (9 examples in 33-94% yield).
Synthesis and Biological Evaluation of 2,3,5-Substituted [1,2,4]Thiadiazoles as Allosteric Modulators of Adenosine Receptors
Van Den Nieuwendijk, Adrianus M. C. H.,Pietra, Daniele,Heitman, Laura,G?bly?s, Anikó,IJzerman, Adriaan P.
, p. 663 - 672 (2007/10/03)
A number of 2,3,5-substituted [1,2,4]thiadiazole analogues of SCH-202676 (N-(2,3-diphenyl-[1,2,4]thiadiazole-5(2H)-ylidene)methanamine, 7a) were synthesized and tested as potential allosteric modulators of adenosine receptors. All compounds were capable of displacing the binding of the radiolabeled agonist [3H]CCPA to human A1 adenosine receptors, whereas modest and varying effects were observed on the binding of [3H]DPCPX, a radiolabeled antagonist for this receptor subtype. Four compounds, 7a (SCH-202676), 7k (LUF5792), 71 (LUF5794), and 8e (LUF5789), were selected for more detailed characterization. They all proved allosteric inhibitors of agonist binding, with 7k being most potent, whereas their effects on antagonist binding were more ambiguous. Subsequently, experiments were done on human adenosine A2A and A3 receptors. Compounds 7a and 7l displayed peculiar displacement characteristics of both radiolabeled agonist and antagonist binding to A2A receptors, whereas 7a showed some activity on A3 receptors.
N-arylbenzonitrilium ions. Photochemical generation and effect of substituents in the phenyl rings on lifetimes in water and reactivity with azide ion
Ruane, Patrick H.,Ahmed, Abid R.,McClelland, Robert A.
, p. 312 - 317 (2007/10/03)
Nitrilium ions Ar-C≡N+-Ar′ have been studied by laser flash photolysis in aqueous solutions containing 20% acetonitrile. The cations were generated by photoheterolysis of benzimidate esters Ar-CZ=N-Ar′ (Z = -OC6H4-4-CN) with 4-cyanophenoxide as the photochemical leaving group. Rate constants for the reaction with water (kw), azide ion (kaz) and hydroxide (kOH) were measured. The cation Ph-C≡N+-Ph is only 50-fold shorter lived in water compared to Ph-C≡N+-iPr (2); thus the effect of replacing an N-alkyl group with N-phenyl is modest. These two cations are also shown to have similar lifetimes to iminium analogs, e.g. Ph-CH=N+ (Me)-Ph. Thus, addition of water to analogous sp and sp2 hybridized systems occurs at a similar rate, and the increased steric access to the nitrilium plays at most a modest role. For the series where substituents in Ar′ were varied with Ar equal to phenyl, the Hammett plot for log kw correlated with σ, with ρ = - 1.4. For the series where Ar was varied, the data correlated much better with σ+, although ρ+ was only -0.6. This remarkably small effect of substituents in Ar constrasts with the effects seen in benzylic carbocations, but is consistent with the nitrilium structure, with most of the positive charge located on the nitrogen. Rate constant ratios kaz:kw, including the N-alkylnitrilium ion 2, are constant at ～104, with values of kaz well below the diffusion limit, even for the most reactive nitrilium ions. This is very different behaviour from that of carbocations and arylnitrenium ions of similar lifetimes in water. For these cations the rate constants kaz would be at or at least approaching the diffusion limit.
AMIDINES. PART IX. INFLUENCE OF SUBSTITUTION AT IMINO AND AMINO NITROGEN ATOMS ON THE BASICITY OF N,N'-DIPHENYLBENZAMIDINES
Oszczapowicz, Janusz,Raczynska, Ewa,Orlinski, Ryszard
, p. 2031 - 2037 (2007/10/02)
A series of 15 unreported N1-metylo-N1,N2-diphenylbenzamidines containing two different substituents at phenyl rings have been synthesized and their pKa values in 99.8percent ethanol were determined.It was found
