Synthesis and stereochemical assignments of diastereomeric Ni(II) complexes of glycine Schiff base with (R)-2-(N-{2-[N-alkyl-N-(1-phenylethyl)amino]acetyl}amino)benzophenone; a case of configurationally stable stereogenic nitrogen.

A family of chiral ligands derived from α-phenylethylamine and 2-aminobenzophenone were prepared by alkylation of the nitrogen atom. Upon reaction with glycine and a Ni(II) salt, these ligands were transformed into diastereomeric complexes, as a result of the configurational stability of the stereogenic nitrogen atom. Different diastereomeric ratios were observed depending on the substituent R introduced in the starting ligand, and stereochemical assignments were based on X-ray analysis, along with NMR studies and optical rotation measurements.

Inexpensive chemical method for preparation of enantiomerically pure phenylalanine.

Here, we report the most inexpensive procedure for chemical synthesis of enantiomerically pure phenylalanine. As a source of chirality, we use the ultimately inexpensive chiral auxiliary, 1-(phenyl)ethylamine, incorporated into the specially designed ligands which form the corresponding intermediate Ni(II) complexes with racemic phenylalanine. Diastereomerically pure Ni(II) complexes, containing either (S)- or (R)-phenylalanine, were disassembled to produce enantiomerically pure target amino acid, along with recycling the chiral ligand. All reactions were conducted under operationally convenient conditions, featuring high yields and thus underscoring attractive cost structure of this method.

(±)-(4bS,8aR,10aS)-10a-Ethynyl-4b,8,8-trimethyl-3,7-dioxo-3,4b,7,8,8a,9,10,10a-octa-hydro-phenanthrene-2,6-dicarbonitrile.

The anti-inflammatory and cytoprotective tricyclic title compound, C(21)H(18)N(2)O(2), also known as TBE-31, crystallizes with two nearly superimposable mol-ecules in the asymmetric unit. In both mol-ecules, the three ring systems conform to an envelope-chair-planar arrangement. The central ring, in a cyclohexane chair conformation, contains an axial ethynyl group that bends slightly off from a nearby axial methyl group because of the 1,3-diaxial repulsion between the two groups. In the crystal, weak C-H⋯N and C-H⋯O inter-actions form chains along [001].

Room-temperature carbonization of poly(diiododiacetylene) by reaction with Lewis bases.

Poly(diiododiacetylene) (PIDA) is a conjugated polymer containing an all-carbon backbone and only iodine atom substituents. Adding a Lewis base to the blue PIDA suspension at room temperature leads first to rapid disappearance of the absorption peaks attributed to PIDA, followed more slowly by release of free iodine. The resulting solid material gives a Raman scattering spectrum consistent with graphitic carbon, and it has a much higher conductivity than PIDA itself. Further investigation has led to the discovery of a previously unreported transformation, the reaction of a Lewis base such as pyrrolidine with a trans-diiodoalkene to form the corresponding alkyne. The generality of this iodine elimination further suggests that reaction of PIDA with Lewis bases dehalogenates the polymer, presenting a new method to prepare carbon nanomaterials at room temperature under very mild conditions.