DNA-Accelerated Copper Catalysis of Friedel-Crafts Conjugate Addition/Enantioselective Protonation Reactions in Water.

DNA-induced rate acceleration has been identified as one of the key elements for the success of the DNA-based catalysis concept. Here we report on a novel DNA-based catalytic Friedel-Crafts conjugate addition/enantioselective protonation reaction in water, which represents the first example of a reaction that critically depends on the >700- to 990-fold rate acceleration caused by the presence of a DNA scaffold. The DNA-induced rate acceleration observed is the highest reported due to the environment presented by a biomolecular scaffold for any hybrid catalyst, to date. Based on a combination of kinetics and binding studies, it is proposed that the rate acceleration is in part due to the DNA acting as a pseudophase, analogous to micelles, in which all reaction components are concentrated, resulting in a high effective molarity. The involvement of additional second coordination sphere interactions is suggested by the enantioselectivity of the product. The results presented here show convincingly that the DNA-based catalysis concept, thanks to the DNA-accelerating effect, can be an effective approach to achieving a chemically challenging reaction in water.

Enantioselective catalysis at the DNA scaffold.

The unique chiral structure and the highly specific Watson-Crick base-pairing interactions that characterize natural double-stranded DNA, make this natural biopolymer an attractive ligand for asymmetric catalytic processes. In this chapter the applications of DNA as scaffold and chiral ligand in enantioselective transition metal catalysis are presented. An overview of the state of the art for the different approaches to metal-DNA based catalysts is given, followed by an overview of the mechanistic studies that have been performed to date.

Antitumor activity of new hydridotris(pyrazolyl)borate ruthenium(II) complexes containing the phosphanes PTA and 1-CH3-PTA.

The synthesis and full characterization of new half-sandwich ruthenium(II) complexes containing κ(3)(N,N,N)-hydridotris(pyrazolyl)borate (κ(3)(N,N,N)-Tp) and the water-soluble phosphanes 1,3,5-triaza-7-phosphatricyclo[3.3.1.1(3,7)]decane (PTA) and 1-methyl-3,5-diaza-1-azonia-7-phosphatricyclo[3.3.1.1(3,7)]decane (1-CH(3)-PTA) has been explored. Single crystal X-ray diffraction analysis for complex [RuCl{κ(3)(N,N,N)-Tp}(PMe(2)Ph)(1-CH(3)-PTA)][CF(3)SO(3)]·2NCMe is also reported. DNA binding properties of the ruthenium complexes have been evaluated by mobility shift assay and MALDI-TOF mass spectrometry. The in vitro antitumor activity of these compounds was assessed by examining their ability to inhibit cell proliferation in a number of human cancer cell lines (NCI-H460, SF-268, MCF-7) and non-tumor human umbilical vein endothelial cells (HUVEC). Some of these new compounds show promising cytotoxic activity with IC(50) values in the low micromolar range, and display differential effects on cancer and normal cell growth.

Facile modification of 1,3,5-triaza-7-phosphatricyclo[3.3.1.1(3,7)]decane phosphanes coordinated to ruthenium(II).

Hydridotris(pyrazolyl)borate (Tp) ruthenium (II) complexes containing new phosphane ligands are described. The new complexes were obtained by electrophilic attack to a coordinated 1,3,5-triaza-7-phosphatricyclo[3.3.1.1(3,7)]decane (PTA) ligand. Thus, cationic complexes [RuX{kappa(3)(N,N,N)-Tp}(PPh(3))(1-R-PTA)][Y] (X = Cl, R = H (1), CH(2)Ph (4), CH(2)CH=CH(2) (6), CH(2)C[triple bond]CH (8); X = I, R = CH(2)Ph (5), CH(2)CH=CH(2) (7)) and neutral [RuCl{kappa(3)(N,N,N)-Tp}(PPh(3))(1-I(2)-PTA)] (3) have been synthesized and characterized. For complexes [RuI{kappa(3)(N,N,N)-Tp}(PPh(3))(1-R-PTA)][Y] (R = CH(2)Ph, CH(2)CH=CH(2)) an unprecedented formal C-H activation has been observed in alcohols leading to complexes with 1-methyl-4-phenyl-3,5-diaza-1-azonia-7-phosphatricyclo[3.3.1.1(3,7)]decane, 4-(2-methoxyethyl)-1-methyl-3,5-diaza-1-azonia-7-phosphatricyclo[3.3.1.1(3,7)]decane and 1-methyl-4-[2-(propan-2-yloxi)ethyl]-3,5-diaza-1-azonia-7-phosphatricyclo[3.3.1.1(3,7)]decane ligands, respectively, and the mechanism explored through deuteriation experiments. The first I(2)-charge transfer compound between I(2) and a nitrogen which belongs to a ligand coordinated to a transition metal, [RuI{kappa(3)(N,N,N)-Tp}(PPh(3))(1-I(2)-PTA)] is described.