Catalytic Asymmetric Decarboxylative Mannich Reaction of Malonic Acid Half Esters with Cyclic Aldimines: Access to Chiral β-Amino Esters and Chroman-4-amines.

An enantioselective decarboxylative Mannich reaction of malonic acid half esters (MAHEs) with cyclic aldimines has been accomplished by employing the copper(I)/(R,R)-Ph-Box complex as chiral catalyst. The desired β-amino esters were obtained in good to high yields with excellent enantioselectivities. Furthermore, one of the corresponding Mannich products could be readily transformed into chiral chroman-4-amines without loss of enantioselectivity, which is a key intermediate of the human Bradykinin B1 receptor antagonist.

[Synthesis and Spectroscopic Study of a Chemosensor for Naked Eye Recognition of Cu2+ and Hg2+].

Compound L, as the procedural sensor for the detection of Cu2+ and Hg2+, was designed and synthesized based on the coumarin-modified rhodamine derivative. The structure of compound L was characterized by NMR, high resolution mass spectrometry and infrared method. Its sensing behavior toward various metal ions was investigated with absorbance methods.

[Synthesis, characterization and interaction with ct-DNA of four novel secondary amine complexes].

A novel ligand(L), (N, N'-bis (4-methylbenzyl) ethane-1, 2-diamine), and its transition metal(II) complex, [ML2 (H2O)2]2+ x 2NO3- (M = Cu(II), Co(II, Ni(II), Zn(II)), have been synthesized and characterized by elemental analysis, IR and 1H NMR. The crystal structure of the Cu-L complex was characterized by X-ray single crystal diffraction, and the results showed a regular octahedral structure in which each metal ion is six--coordinated with four nitrogen atoms from two ligands and two oxygen atoms from two water molecules. The interaction of the complex with calf thymus DNA was investigated by UV spectroscopy and fluorescence spectroscopy, and the results suggest that the complex binds to DNA by electrostatic interaction mode.

Bis(μ-N-benzyl-N-tetra-decyl-dithio-carbamato-κS:S')bis-[(N-benzyl-N-tetra-decyl-dithio-carbamato-κS,S')zinc(II)].

In the title compound, [Zn(2)(C(22)H(36)NS(2))(4)], two bidentate dithio-carbamate groups chelate directly to the Zn(II) atoms, whereas the two remaining dithio-carbamate ligands bridge the Zn atoms via a crystallographic inversion centre. The Zn atoms show a strongly distorted tetra-hedral geometry. Adding the long S⋯S distance with the inversion centre being in the middle, the resulting five-coordinate geometry around the Zn atoms can be considered to be between distorted recta-ngular pyramidal and trigonal bipyramidal, with a calculated τ value of 0.