Synthesis of Vicinal Carbocycles by Intramolecular Nickel-Catalyzed Conjunctive Cross-Electrophile Coupling Reaction.

A nickel-catalyzed intramolecular conjunctive cross-electrophile coupling reaction has been established. This method enables the synthesis of 3,5-vicinal carbocyclic rings found in numerous biologically active compounds and natural products. We provide mechanistic experiments that indicate this reaction proceeds through alkyl iodides formed in situ, initiates at the secondary electrophilic center, and proceeds through radical intermediates.

Nickel-Catalyzed Kumada Cross-Coupling Reactions of Benzylic Sulfonamides.

Herein, we report a Kumada cross-coupling reaction of benzylic sulfonamides. The scope of the transformation includes acyclic and cyclic sulfonamide precursors that cleanly produce highly substituted acyclic fragments. Preliminary data are consistent with a stereospecific mechanism that allows for a diastereoselective reaction.

Engaging Sulfonamides: Intramolecular Cross-Electrophile Coupling Reaction of Sulfonamides with Alkyl Chlorides.

The application of amine derivatives as coupling partners is rare due to the inherent strength of the C-N bond. Herein, we report the first cross-electrophile coupling reaction of unstrained benzylic sulfonamides. Nickel-catalyzed intramolecular cross-electrophile coupling reactions of acyclic and cyclic benzylic sulfonamides with pendant alkyl chlorides generate cyclopropane products.

Enantioselective Vanadium-Catalyzed Oxidative Coupling: Development and Mechanistic Insights.

The evolution of a more reactive chiral vanadium catalyst for enantioselective oxidative coupling of phenols is reported, ultimately resulting in a simple monomeric vanadium species combined with a Brønsted or Lewis acid additive. The resultant vanadium complex is found to effect the asymmetric oxidative ortho-ortho coupling of simple phenols and 2-hydroxycarbazoles with good to excellent levels of enantioselectivity. Experimental and quantum mechanical studies of the mechanism indicate that the additives aggregate the vanadium monomers.

Asymmetric Oxidative Coupling of Phenols and Hydroxycarbazoles.

The first examples of asymmetric oxidative coupling of simple phenols and 2-hydroxycarbazoles are outlined. Generation of a more vanadium catalyst by ligand design and by addition of an exogenous Brønsted or Lewis acid was found to be key to coupling the more oxidatively resistant phenols. The resultant vanadium complex is both more Lewis acidic and more strongly oxidizing.

Hepatitis E in England and Wales.

In 2005, 329 cases of hepatitis E virus infection were confirmed in England and Wales; 33 were confirmed indigenous infections, and a further 67 were estimated to be indigenous infections. Hepatitis E should be considered in the investigation of patients with hepatitis even if they have no history of travel.

The effect of malaria on mortality in a cohort of HIV-infected Ugandan adults.

Objectives: To investigate the effects of malaria parasitaemia and clinical malaria on mortality in HIV seropositive and seronegative adults.

Methods: A cohort of adults in rural Uganda were followed from 1990 to 1998. Participants attended routine clinic visits every 3 months and also when sick (interim visits).