Solvent-free routes to clean technology

A major aim for the chemical technology of the future is the avoidance of n oxious and environmentally unacceptable organic solvents. In this concept a rticle we discuss more environmentally friendly and highly selective altern atives which we have evolved for carrying out a number of important chemica l conversions. These entail the use of porous heterogeneous catalysts in wh ich the active sites have been atomically engineered and fully characterize d. Such solid catalysts operate under solvent-free conditions and usually e ntail one-step processes.