Suzuki cation effect

Similar to the case of Suzuki couplings (6.1.2), ally lie alkylations can also be run in neat water as solvent in the presence of surfactants. In addition to the general solubihzation effect, the amphiphiles may also have a specific influence on the reaction rate. For example, the reaction of the P-ketoester substrate on Scheme 6.22 with allyl acetate, catalyzed by [Pd(PPh3)4] was only slightly accelerated by the anionic SDS (1.5 h, 18 % yield), however, the reaction rate dramatically increased in the presence of the cationic CTAB and the neutral Triton X-100 detergents, leading to 74 % and 92% yields in 1.5 h and 5 min ( ), respectively [51]. Several other carbonucleophiles were alkylated in such emulsions with excellent yields. 

Kameo A, Suzuki A, Torigoe K, Esumi K (2001) Fiber-like Gold Particles Prepared in Cationic Micelles by UV Irradiation Effect of Alkyl Chain Length of Cationic Surfactant on Particle Size. J Colloid Interface Sci 241 89-292... 

Suzuki, I., and S. Ogawa Effect of addition of cations on the simultaneous grafting of styrene to rayon by gamma-irradiation. J. Appl. Polymer Sci. 7, 2067 <1963). 

Suzuki et al. examined the effect of various divalent cations on purified recombinant human GCH expressed in Escherichia coli to clarify the molecular mechanism of action of divalent cations on the GCH enzymatic activity [150]. They demonstrated that GCH utilizes metal-free GTP as the substrate for the enzyme reaction. Inhibition of the GCH activity by divalent cations such as Mg(II) and Zn(II) was due to a reduction in the concentration of metal-free GTP substrate by complex formation. Many nucleotidehydrolyzing enzymes such as G proteins and kinases recognize Mg-GTP or Mg-ATP complex as their substrate. In contrast with these enzymes, Suzuki et al. demonstrated that GCH activity is dependent on the concentration of Mg-free GTP [150]. 

Walsh SL, Preston KL, SuUivan JT, Fromme R, Bigelow GE (1994) Fluoxetine alters the effects of intravenous cocaine in humans. J Clin Psychopharmacol 14 396-407 Weyand S, Shimamura T, Yajima S, Suzuki S, Mirza O, Krusong K, Carpenter EP, Rutherford NG, Hadden JM, O Reilly J, Ma P, Saidijam M, Patching SG, Hope RJ, Norbertczak HT, Roach PC, Iwata S, Henderson PJ, Cameron AD (2008) Structure and molecular mechanism of a nucleobase-cation-symport-1 family transporter. Science 322 709-713... 

Suzuki et al. (1986) measured the onset of precipitation of LnfOH), by optical detection. To avoid local concentration effects, the hydroxide ion was generated electrolytically. The pH values associated with initial precipitation in this study were substantially lower than those reported earlier (Moeller and Kremer 1945), presumably, due to differences in the sensitivity of detection. A plot of the pH of initial precipitation as a function of the radius of the lanthanide cations was an S-shaped... 

Ikeda, A. Suzuki. Y. Yoshimura. M. Shinkai. S. On the prerequisites for the formation of solution complexes from [60]fullerene and calix[n]arenes A novel allosteric effect between [6]fullerene and metal cations in calix[-njaryl ether complexes. Tetrahedron 1998. 54. 2497-2508. 

Using pulse radiolysis methods, the radical cations and the radical anions of (all-E)-retinaldehyde (2) and polyenones were produced, and their absorption spectra were measured. A linear dependence of the wavelength maximum of the absorption bands on the number of conjugated double bonds, as well as a pronounced solvent effect, was found (Land et al.y 1978). To analyze the steric effects of the side-chain methyl groups in retinaldehydes, the ir-electronic states of norretinaldehydes were calculated, and these calculated states were compared with measured absorption maxima (Suzuki et al.y 1979). 

Reiser, A., Photoreactive Polymers — The Science and Technology of Resists, Wiley, New York, 1989. Anzai, J., Suzuki, Y., Ueno, A., and Osa, T, Cation transport through Hquid membranes mediated by photoreactive crown ethers. Effects of alkali metal cations on their photoreactivities and transporting properties, Isr. J. Chem., 26, 60, 1985. 

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