C–H Functionalization Reactivity of a Nickel–Imide

This article discusses C-H functionalization reactivity of a Nickel-Imide

Comparison of the Activity of Free and Liposomal Amphotericin B In Vitro and in a Model of Systemic and Localized Murine Candidiasis

Because of the toxicity of amphotericin B-desoxycholate (AmB-d) during systemic therapy, less toxic forms of AmB, which promise to have a broader therapeutic index, are under investigation. There is, however, no convincing explanation of how such preparations might be made less toxic yet retain their antifungal efficacy. In this study, the antifungal activity of a less toxic, unilamellar liposomal (1) preparation of AmB (AmBisome), which is commercially available in some countries, was compared with conventional AmB-d in vitro and in models of systemic and localized candidiasis in immunosuppressed mice. Results indicate that 1AmB has four to eight times less antifungal activity than AmB-d in all experimental settings tested. Because 1AmB is significantly less active, the therapeutic index of such preparations must be tested clinically before their use can be recommended solely on the basis of toxicity dat

Experimental and Computational Studies of the Ruthenium-Catalyzed Hydrosilylation of Alkynes: Mechanistic Insights into the Regio- and Stereoselective Formation of Vinylsilanes

The ruthenium hydride complex (PCy₃)₂(CO)­RuHCl was found to be a highly effective catalyst for the regio- and stereoselective hydrosilylation of alkynes to form vinylsilane products. (<i>Z</i>)-Vinylsilane products were selectively formed for sterically nondemanding terminal alkynes, while (<i>E</i>)-vinylsilane products resulted from sterically demanding terminal alkynes. Kinetic data were obtained from the hydrosilylation of phenylacetylene. The phosphine inhibition study showed an uncompetitive Michaelis–Menten type of inhibition kinetics. The empirical rate law rate = <i>k</i>_obs[<b>1</b>]¹[alkyne]⁰[silane]⁰ was established from the reaction rate as a function of both [alkyne] and [silane]. DFT calculations were performed and found that <i>Z</i>/<i>E</i> isomerization is facile via a metallacyclopropene transition state and that the isomerization occurs prior to the silane substrate binding. A detailed mechanistic scheme on the hydrosilylation reaction has been delineated on the basis of both experimental and computational data

Mechanism of Hydrogenolysis of an Iridium Methyl Bond: Evidence for a Methane Complex Intermediate

Article on the mechanism of hydrogenolysis of an iridium methyl bond and evidence for a methane complex intermediate

Experimental and Computational Studies of the Ruthenium-Catalyzed Hydrosilylation of Alkynes: Mechanistic Insights into the Regio- and Stereoselective Formation of Vinylsilanes

The ruthenium hydride complex (PCy₃)₂(CO)­RuHCl was found to be a highly effective catalyst for the regio- and stereoselective hydrosilylation of alkynes to form vinylsilane products. (<i>Z</i>)-Vinylsilane products were selectively formed for sterically nondemanding terminal alkynes, while (<i>E</i>)-vinylsilane products resulted from sterically demanding terminal alkynes. Kinetic data were obtained from the hydrosilylation of phenylacetylene. The phosphine inhibition study showed an uncompetitive Michaelis–Menten type of inhibition kinetics. The empirical rate law rate = <i>k</i>_obs[<b>1</b>]¹[alkyne]⁰[silane]⁰ was established from the reaction rate as a function of both [alkyne] and [silane]. DFT calculations were performed and found that <i>Z</i>/<i>E</i> isomerization is facile via a metallacyclopropene transition state and that the isomerization occurs prior to the silane substrate binding. A detailed mechanistic scheme on the hydrosilylation reaction has been delineated on the basis of both experimental and computational data