Untethering sparteine: 1,3-diamine ligand for asymmetric synthesis in water

Chiral ligands are the toolbox for asymmetric synthesis to access 3D molecular world. Enabling efficient asymmetric reaction in water is a big challenge. As moisture/air stable and strong binding moieties, amines, compared to imine and phosphine ligands, are ideal candidates to accommodate asymmetric transformations in water. Known amine ligands like Proline analogues and Cinchona alkaloids showed excellent asymmetric induction. Sparteine, an alkaloid studied originated in 1968, had never been considered as a privileged catalyst due to its structure defection which led to poor reaction compatibility and unsatisfactory stereoselectivity. Here, we report the design of a chiral diamine catalyst untethering one of the sparteine rings. The diamine catalyst was easily accessed in two steps on 100 gram-scale. This chiral ligand was proved to be efficient for addition reactions in water providing products with excellent yields and enantiomeric ratios. This pluripotent catalyst has also shown good reactivity/enantioselectivity under organocatalysis, Cu and Pd-catalysed conditions. We anticipate that the ligand would allow further development of other catalysts for important yet challenging green stereoselective transformations.

Ferrous Complexes with Bis (Meo) in Α-Substituted Tris (Pyridin-2-Ylmethyl) Amine Ligands: Effect of the Bis (Meo) in Α- Substituents in Dioxygen Activation and Biomimetic Reactivity

This report describes how the coordination of FeCl2 with tris(pyridin-2-ylmethyl)amine (TPA) ligands offers the possibilty to activate the molecular dioxygen in biomimetic processes. . It includes all procedures taken to the case for major oxidation reactions carried out in Nature under particular conditions. The aim of the this paper is to present the outcome of a thorough study for complex coordinations with ligands substituted by groups known as electron donors. It demonstrates how ligands with methoxy substituents are likely to be demethylated, and therefore providing entities potentially useful in synthesis. Targeting in modulating the electronic properties at the metal center, a new type of ligand (MeO)2TPA has been prepared and the complex of (MeO)2TPAFeCl2 has been studied by uv-visble ; 1H RMN paramagnatic and conductometry. The effect of (MeO) group in α-substituted on the structure as well as the effect of substitution on the oxygenation of the complex has been verified. Afterwards, the reactivity of the complex towards molecular dioxygen in absence of substrat is checked by uv-visble, 1H RMN paramagnatic and radiocristallography. As well, the reactivity in presence of substrat is tested.

Ferrous Complexes with Bis Meo in Α Substituted Tris Pyridin 2 Ylmethyl Amine Ligands Effect of the Bis Meo in Α Substituents in Dioxygen Activation and Biomimetic Reactivity

This report describes how the coordination of FeCl2 with tris(pyridin-2-ylmethyl)amine (TPA) ligands offers the possibilty to activate the molecular dioxygen in biomimetic processes. . It includes all procedures taken to the case for major oxidation reactions carried out in Nature under particular conditions. The aim of the this paper is to present the outcome of a thorough study for complex coordinations with ligands substituted by groups known as electron donors. It demonstrates how ligands with methoxy substituents are likely to be demethylated, and therefore providing entities potentially useful in synthesis. Targeting in modulating the electronic properties at the metal center, a new type of ligand (MeO)2TPA has been prepared and the complex of (MeO)2TPAFeCl2 has been studied by uv-visble ; 1H RMN paramagnatic and conductometry. The effect of (MeO) group in α-substituted on the structure as well as the effect of substitution on the oxygenation of the complex has been verified. Afterwards, the reactivity of the complex towards molecular dioxygen in absence of substrat is checked by uvvisble, 1H RMN paramagnatic and radiocristallography. As well, the reactivity in presence of substrat is tested.

catena-Poly[[bis(quinolin-8-amine-κ2 N,N′)cadmium(II)]-μ-cyanido-κ2 N:C-[dicyanidonickel(II)]-μ-cyanido-κ2 C:N]

In the title compound, [CdNi(C9H8N2)2(CN)4] n , the Cd and Ni atoms both lie on centres of inversion in space group P21/c. The Cd atom is coordinated by two bidentate quinolin-8-amine ligands and by the N atoms of two cyano ligands, while the square planar Ni atom is coordinated by the C atoms of four cyano ligands. These units form a one-dimensional coordination polymer containing an (–NC—Ni—CN—Cd–) n backbone, and the coordination polymer chains are linked into a three-dimensional array by a combination of N—H...N and C—H...N hydrogen bonds, augmented by a π–π stacking interaction.