Trimerization and cyclization of reactive P-functionalities confined within OCO pincers.

In order to stabilize a 10-P-3 species with symmetry and two lone pairs on the central phosphorus atom, a specialized ligand is required. Using an NCN pincer, previous efforts to enforce this planarized geometry at P resulted in the formation of a -symmetric, 10π-electron benzazaphosphole that existed as a dynamic "bell-clapper" in solution. Here, OCO pincers 1 and 2 were synthesized, operating under the hypothesis that the more electron-withdrawing oxygen donors would better stabilize the 3-center, 4-electron O-P-O bond of the 10-P-3 target and the sp-hybridized benzylic carbon atoms would prevent the formation of aromatic P-heterocycles.

Solvent free selective dehydrogenation of indolic and carbazolic molecules with an iridium pincer catalyst.

A previously known iridium POCOP pincer catalyst was found to selectively dehydrogenate the heterocyclic portion of several indolic and carbazolic molecules. These molecules were found to have an "activity window" (172-178 °C) upon which only the heterocyclic ring underwent dehydrogenation. All reactions were run solvent free, yields for selected substrates were excellent, and the products were isolated by either distillation or alumina plug filtration.

Homogeneous, anaerobic (N-heterocyclic carbene)-Pd or -Ni catalyzed oxidation of secondary alcohols at mild temperatures.

The use of aryl chlorides as oxidants for the selective oxidation of a variety of secondary alcohols in anaerobic conditions with (NHC)-Pd and -Ni systems (NHC = N-heterocyclic carbene) at very mild temperatures is presented.

Oxygenation of zinc dialkyldithiocarbamate complexes: isolation, characterization, and reactivity of the stoichiometric oxygenates.

S-oxygenation of dithiocarbamate (DTC) complexes has been implicated in their function as industrial anti-oxidants, as well as in their use as pesticides and most recently in their cumulative toxicity, but little is known of the species generated. Several S-oxygenated derivatives of N,N-disubstituted DTCs have been synthesized, characterized by a variety of methods, and their structure and reactivity examined. Low-temperature reaction of bis(N,N-diethyldithiocarbamato)zinc(II), Zn(deDTC)2 1, with oxygenating reagents (hydrogen peroxide, m-chloroperbenzoic acid, urea hydrogen peroxide) yields mono-oxygenated DTC complexes (N,N-peroxydiethyldithiocarbamato)(N,N-diethyldithiocarbamato)zin(II), Zn(O-deDTC)(deDTC), 2 and bis(N,N-peroxydiethyldithiocarbamato)zinc(II), Zn(O-deDTC)2, 3.

A novel heterocyclic atom exchange reaction with Lawesson's reagent: a one-pot synthesis of dithiomaltol.

A one-pot reaction of maltol with Lawesson's reagent generates dithiomaltol, a thiopyran-4-thione, via an unusual heterocyclic atom exchange (HCAE) reaction; only pyrones with proton or aliphatic substituents undergo the HCAE substitution.

Disulfiram facilitates intracellular Cu uptake and induces apoptosis in human melanoma cells.

The alcohol-abuse deterrent disulfiram (DSF) is shown to have a highly selective toxicity against melanoma in culture, inducing a largely apoptotic response, with much lower toxicity against several other cell lines. Melanoma cell lines derived from different stages (radial, vertical, and metastatic phase) were all sensitive to DSF treatment in vitro; melanocytes were only slightly affected. A required role of extracellular Cu is demonstrated for DSF toxicity.