This project deals with the development of new asymmetric reactions catalyzed by metal-DNA hybrids in aqueous medium. The present proposal has two main features:(i) The first feature lies on the design of novel catalytic systems putting into practice the concept of DNA-based asymmetric catalysis presented in the year 2005 by Ben. L. Feringa and G. Roelfes. This methodology involves the modular assembly of a DNA-based catalyst from natural duplex DNA and a metal complex of a nonchiral ligand that can bind to DNA. In the present proposal, the asymmetric addition of ammonia to α,β-unsaturated substrates in aqueous medium will be studied using as catalysts hybrids Cu(II)-DNA, initially. After the optimization of the reaction conditions, the synthetic applicability of this process on the synthesis of intermediates of natural products and compounds with biological interest will be studied. Furthermore, the mechanistic study of the catalytic reaction will lead to achieve a better knowledge about the role and influence of DNA in this asymmetric process. Subsequently, this information can be applied in the development of new catalytic asymmetric reactions. Thus, the catalytic activity of new metal centres (i.e. scandium(III)) will be explored and applied to the concept of metal-DNA based catalysts in the asymmetric Michael addition in water to broaden further the scope of this transformation.(ii)The second feature of this proposal lies in the fact that all these catalytic processes will be developed in accordance with the principles of Green Chemistry, where the application of catalytic technologies, atom-efficiency and innocuous reaction solvents are main characteristics of the processes presented in these proposal. Finally, this will contribute towards the development of novel friendly environmental transformations.