to generate the desired product and regenerate the LnM-X complex. To avoid free-radical reactions http://www.selleckchem.com/products/BAY-73-4506.html possible with the direct use of O-2, our approach is based on the use of air-recyclable oxidants. In addition, the solvent serves several roles induding protection of the product, generation of highly active catalysts, and in some cases, as the air-regenerable oxidant.

We postulate that there could be three distinct classes of catalyst/oxidant/solvent systems. The established electrophilic class combines electron-poor catalysts in acidic solvents that conceptually react by net removal of electrons from the bonding orbitals of the CH bond. The solvent protects the CH3OH by conversion to more electron-poor [CH3OH2](+) or the ester and also increases the electrophilicity of the catalyst by ligand protonation.

The nucleophilic class matches electron-rich catalysts with basic solvents and conceptually reacts by net donation of electrons to the antibonding orbitals of the CH bond. In this case, the solvent could protect the CH3OH by deprotonation to the more electron-rich (CH3O](-) and increases the nudeophilicity of the catalysts by ligand deprotonation. The third grouping involves ambiphilic catalysts that can conceptually react with both the HOMO and LUMO of the CH bond and would typically involve neutral reaction solvents. We call this continuum base- or acid-modulated (BAM) catalysis.

In this Account, we describe our efforts to design catalysts following these general principles.

We have had the most success with designing electrophilic systems, but unfortunately, the essential role of the acidic solvent also led to catalyst inhibition by CH3OH above similar to 1 M. The ambiphilic catalysts reduced this product inhibition but were too slow and inefficient. To date, we have designed Drug_discovery new base-assisted CH activation and LnM-R fuctionalization reactions somehow and are working to integrate these into a complete, working catalytic cycle. Although we have yet to design a system that could supplant commercial processes, continued exploration of the BAM catalysis continuum may lead to new systems that will succeed in addressing this valuable goal.”
“Limited natural resources, high energy consumption, economic considerations, and environmental concerns demand that we develop new technologies for the sustainable production of chemicals and fuels. New methods that combine the selective activation of C H bonds of hydrocarbons with oxidation by a green oxidant such as molecular oxygen would represent huge advances toward this goal. The spectacular selectivity of transition metals in deaving C H bonds offers the potential for the direct use of hydrocarbons in the production of value-added organics such as alcohols.