Efficient carbene transfer reactivity mediated by Fe(II) complexes supported by bulky alkoxides.

Herein we describe the stoichiometric and catalytic carbene-transfer reactivity of iron(II) alkoxide complexes with iodonium ylide precursors. Treatment of PhIC(COMe) with styrene in the presence of catalytic amounts of several different Fe(OR)(THF) precursors results in efficient cyclopropanation for a variety of styrenes. Computational and reactivity studies suggest a novel remote metallocarbene/vinyl radical intermediate, Fe(OR)(κ-(OC(OMe))C), which could be responsible for the reactive nature of the catalyst.

Aziridination Reactivity of a Manganese(II) Complex with a Bulky Chelating Bis(Alkoxide) Ligand.

Treatment of Mn(N(SiMe))(THF) with bulky chelating bis(alkoxide) ligand [1,1':4',1''-terphenyl]-2,2''-diylbis(diphenylmethanol) (H[O-terphenyl-O]) formed a seesaw manganese(II) complex Mn[O-terphenyl-O](THF), characterized by structural, spectroscopic, magnetic, and analytical methods. The reactivity of Mn[O-terphenyl-O](THF) with various nitrene precursors was investigated. No reaction was observed between Mn[O-terphenyl-O](THF) and aryl azides.

Catalytic synthesis of azoarenes metal-mediated nitrene coupling.

Various valuable properties of azoarenes ("azo dyes"), including their vivid colors and their facile - photoisomerization, lead to their wide use in the chemical industry. As a result, ∼700 000 metric tons of azo dyes are produced each year. Most currently utilized synthetic methods towards azoarenes involve harsh reaction conditions and/or toxic reagents in stoichiometric amounts, which may affect selectivity and produce significant amounts of waste.

Synthesis, electronic structures, and reactivity of mononuclear and dinuclear low-valent molybdenum complexes in iminopyridine and bis(imino)pyridine ligand environments.

Molybdenum in redox non-innocent ligand environments features prominently in biological inorganic systems. While Holm and coworkers, along with many other researchers, have thoroughly investigated formally high-oxidation-state molybdenum (Mo(IV)-Mo(VI)) ligated by dithiolenes, less is known about molybdenum in other formal oxidation states and/or different redox-active ligand environments. This work focuses on the investigation of low-valent molybdenum in four different redox non-innocent nitrogen ligand type environments (mononucleating and dinucleating iminopyridine, mononucleating and dinucleating bis(imino)pyridine).

Synthesis and structure of a new bulky bis-(alkoxide) ligand on a terphenyl platform.

A new sterically bulky chelating bis-(alkoxide) ligand 3,3'-([1,1':4',1''-terphen-yl]-2,2''-di-yl)bis-(2,2,4,4-tetra-methyl-pentan-3-ol), (H[OO]), was prepared in a two-step process as the di-chloro-methane monosolvate, CHO·CHCl. The first step is a Suzuki-Miyaura coupling reaction between 2-bromo-phenyl-boronic acid and 1,4-di-iodo-benzene. The resulting 2,2''-di-bromo-1,1':4',1''-terphenyl was reacted with BuLi and hexa-methyl-acetone to obtain the desired product.

Synthesis and Cu(I)/Mo(VI) Reactivity of a Bifunctional Heterodinucleating Ligand on a Xanthene Platform.

In an effort to probe the feasibility of a model of Mo-Cu CODH (CODH = carbon monoxide dehydrogenase) lacking a bridging sulfido group, the new heterodinucleating ligand LH was designed and its Cu(I)/Mo(VI) reactivity was investigated. LH (()-3-(((5-(bis(pyridin-2-ylmethyl)amino)-2,7-di--butyl-9,9-dimethyl-9-xanthen-4-yl)imino)methyl)benzene-1,2-diol) features two different chelating positions bridged by a xanthene linker: bis(pyridyl)amine for Cu(I) and catecholate for Mo(VI). LH was synthesized via the initial protection of one of the amine positions, followed by two consecutive alkylations of the second position, deprotection, and condensation to attach the catechol functionality.

Synthesis of Chromium(II) Complexes with Chelating Bis(alkoxide) Ligand and Their Reactions with Organoazides and Diazoalkanes.

Synthesis of new chromium(II) complexes with chelating bis(alkoxide) ligand [OO] (H[OO] = [1,1':4',1''-terphenyl]-2,2''-diylbis(diphenylmethanol)) and their subsequent reactivity in the context of catalytic production of carbodiimides from azides and isocyanides are described. Two different Cr(II) complexes are obtained, as a function of the crystallization solvent: mononuclear Cr[OO](THF) (in toluene/THF, THF = tetrahydrofuran) and dinuclear Cr([OO]) (in CHCl/THF). The electronic structure and bonding in Cr[OO](THF) were probed by density functional theory calculations.

Tying the alkoxides together: an iron complex of a new chelating bulky bis(alkoxide) demonstrates selectivity for coupling of non-bulky aryl nitrenes.

New chelating bis(alkoxide) ligand H[OO] and its iron(ii) complex Fe[OO](THF) are described. The coordination of the ligand to the metal center is reminiscent of the coordination of two monodentate alkoxides in previously reported Fe(OR)(THF) species. Fe[OO](THF) catalyzes selective and efficient dimerization of non-bulky aryl nitrenes to yield the corresponding azoarenes.

PyGlobal: A toolkit for automated compilation of DFT-based descriptors.

Density Functional Theory (DFT)-based Global reactivity descriptor calculations have emerged as powerful tools for studying the reactivity, selectivity, and stability of chemical and biological systems. A Python-based module, PyGlobal has been developed for systematically parsing a typical Gaussian outfile and extracting the relevant energies of the HOMO and LUMO. Corresponding global reactivity descriptors are further calculated and the data is saved into a spreadsheet compatible with applications like Microsoft Excel and LibreOffice.

Exploring isoxazole and carboxamide derivatives as potential non-nucleoside reverse transcriptase inhibitors.

Nonnucleoside reverse transciptase inhibitors (NNRTI) are a class of drug molecules with a specific target of HIV-1 reverse transcriptase (RT). In the present work, we evaluated a set of selected oxazole and carboxamide derivatives to identify potential pharmacophoric features using molecular docking approach. The docking approach employed has been validated by enrichment factor calculation at top 1% (EF1%).