Scientists come a step closer to organic reactions in water

Toronto, June 27 (IANS) Researchers have discovered a way to use water as a solvent in one of the reactions most widely used to synthesise chemical products and pharmaceuticals.

The researchers discovered a catalytic system allows direct metal-mediated reactions between aryl halides and carbonyl compounds in water.

The new aqueous approach promises to "streamline synthetic sequences and make them safer and more efficient", said Chao-Jun Li from McGill University in Canada.

The findings mark a potential milestone in efforts to develop organic reactions in water.

For the past two decades, researchers have been exploring ways to do away with chemists' traditional reliance on non-renewable petrochemical feedstocks and toxic solvents.

One important method has involved replacing the toxic solvents used in metal-mediated reactions with water - something that was previously considered impossible.

While researchers have succeeded in using water in metal-mediated reactions between carbonyl compounds and other halides, attempts to do so for the most challenging reaction, between aryl halides and carbonyl compounds, have never worked - until now.

Rhodium -- a metal primarily used in the catalytic converters of automobiles -- as a catalyst together with zinc as a mediator can make the reaction possible in water, the new study found.

This new technique bypasses a number of challenges posed by conventional practices in carrying out this reaction, which is widely used in synthesising fine chemicals, biologically active molecules and pharmaceuticals.

Traditional methods, discovered more than a century ago, require that moisture and air be carefully excluded from the process.

The findings appeared in the journal Nature Communications.