Diazene-Catalyzed Oxidative Alkyl Halide-Olefin Metathesis

The first platform for oxidative alkyl halide-olefin metathesis is described. The procedure employs diazenes as catalysts, which effect the cyclization of alkenyl alkyl halides to generate cyclic olefins and carbonyl products. The synthesis of phenanthrene, coumarin, and quinolone derivatives is demonstrated as well as the potential to apply this strategy to other electrophiles.

Theoretical and Experimental Vibrational Characterization of Biologically Active Nd(III) Complex

The neodymium(III) complex of orotic acid (HOA) was synthesized and its structure determined by means of analytical and spectral analyses. Detailed vibrational analysis of HOA, sodium salt of HOA, and Nd(III)–OA systems based on both the calculated and experimental spectra confirmed the suggested metal–ligand binding mode. Significant differences in the IR and Raman spectra of the complex were observed as compared to the spectra of the ligand. The calculated vibrational wavenumbers, including IR intensities and Raman scattering activities, for the ligand and its Nd(III) complex were in good agreement with the experimental data. The vibrational analysis performed for the studied species, orotic acid, sodium salt of orotic acid, and its Nd(III) complex helped to explain the vibrational behaviour of the ligand’s vibrational modes, sensitive to interaction with Nd(III). In this paper we also report preliminary results about the cytotoxicity of the investigated compounds. The cytotoxic effects of the ligand and its Nd(III) complex were determined using the MTT method on different tumour cell lines. The screening performed revealed that the tested compounds exerted cytotoxic activity upon the evaluated cell lines.

Structural verification of a tetrahydrotetrazole compound

Tetrahydrotetrazoles are five-membered-ring heterocycles containing four contiguous saturated nitrogen atoms. Very few examples of such compounds have been reported in the literature. Our previous attempt at the synthesis of a member of this class of compound suggested that the N—N bonds may be more labile than expected. This finding raised the question as to whether the structures of any of the previously reported tetrahydrotetrazoles had been properly assigned. We have reproduced the synthesis of a reported tetrahydrotetrazole, namely 1,2-di-tert-butyl 3-phenyl-1H,2H,3H,10bH-[1,2,3,4]tetrazolo[5,1-a]isoquinoline-1,2-dicarboxylate, C25H30N4O4, and have now confidently confirmed its structure via X-ray crystallography. However, while sufficiently stable in the crystal phase, we discovered that it remains very labile in solution (having a half-life of only 15 min at 20 °C in CDCl3). A tentative reaction pathway for its dissociation based on 1H NMR spectral evidence is provided.

The Hydrazine-O2 Redox Couple as a Platform for Organocatalytic Oxidation: Benzo[c]cinnoline-Catalyzed Oxidation of Alkyl Halides to Aldehydes

An organocatalytic oxidation platform that capitalizes on the capacity of hydrazines to undergo rapid autoxidation to diazenes is described. Commercially available benzo[c]cinnoline is shown to catalyze the oxidation of alkyl halides to aldehydes in a novel mechanistic paradigm involving nucleophilic attack, prototropic shift, and hydrolysis. The hydrolysis and reoxidation events occur readily with only adventitious oxygen and water. A survey of the scope of viable substrates is shown along with mechanistic and computational studies that give insight into this mode of catalysis.