Synthesis and Selected Physicochemical Properties of Complex Na<Subscript>2</Subscript>[Zr(MoO<Subscript>4</Subscript>)<Subscript>3</Subscript>]

The interaction of Zr(NO₃)₄ and Na₂MoO₄ in an aqueous medium has been studied by the method of residual concentrations at 20°C. The compound Nа₂[Zr(MoO₄)₃] is formed starting at the molar ratio Zr(NO₃)₄/Na₂MoO₄ ≥ 0.66. The compound has been characterized by X-ray diffraction, IR spectroscopy, and thermal analysis.     

Copper-catalyzed enantioselective conjugate addition of grignard reagents to acyclic enones

A highly enantioselective Cu-catalyzed addition of Grignard reagents to acyclic aliphatic enones is described. In the presence of 5 mol % of CuBr.SMe2 and 6 mol % of JosiPhos diphosphine aliphatic enones react with Grignard reagents to provide beta-substituted linear ketones with high yields, regio-, and enantioselectivities.     

Optical absorption in a semiconductor cylindrical nanolayer

In the effective-mass approximation the single-electron states in a semiconductor cylindrical nanolayer in the regime of strong quantization are considered. The explicit form of the energy spectrum and envelope wave functions of single-electron states is obtained in the case of large and moderate radii of the system. The corresponding absorption bands of dipole and quadrupole optical transitions in the layer are calculated.     

An iterative catalytic route to enantiopure deoxypropionate subunits: asymmetric conjugate addition of grignard reagents to alpha,beta-unsaturated thioesters

A highly enantioselective (up to 96% ee) conjugate addition of Grignard reagents, in particular, MeMgBr, to alpha,beta-unsaturated thioesters is provided as well as its application to a diastereo- and enantioselective iterative route to syn- and anti-1,3-dimethyl arrays and deoxypropionate subunits. The versatility of the method is illustrated in the synthesis of (-)-lardolure, a multimethyl-branched insect natural pheromone.     

The asymptotically sharp Korn interpolation and second inequalities for shells

We consider shells in three-dimensional Euclidean space that have bounded principal curvatures. We prove Korn's interpolation (or the so-called first and a half¹) and the second inequalities on that kind of shells for $\mathit{u}\in W^{1,2}$ vector fields, imposing no boundary or normalization conditions on u. The constants in the estimates are optimal in terms of the asymptotics in the shell thickness h, having the scalings h or $O(1)$. The Korn interpolation inequality reduces the problem of deriving any linear Korn type estimate for shells to simply proving a Poincaré-type estimate with the symmetrized gradient on the right-hand side. In particular, this applies to linear geometric rigidity estimates for shells, i.e. Korn's fist inequality without boundary conditions.     

Synthesis of New Derivatives of 4-(1,4-Benzodioxan-2-yl)thiophene

Russian Journal of Organic Chemistry - thyl 2-amino-4-(1,4-benzodioxan-2-yl)thiophene-3-carboxylate was synthesized by the Gewald reaction of 2-acetyl-1,4-benzodioxane with ethyl 2-cyanoacetate and...     

One-Pot Syntheses with 2-Substituted 6-Aminopyrimidin-4(3H)-ones: New 5-Aryl-5,8,9,10-tetrahydropyrimido[4,5-b]-quinoline-4,6(3H,7H)-diones and 5,5′-(Arylmethylene)-bis[6-amino-2-methylpyrimidin-4(3H)-ones]

Russian Journal of Organic Chemistry - One-pot condensation of 2-substituted 6-aminopyrimidin-4(3H)-ones with aromatic aldehydes and 5,5-dimethylcyclohexane-1,3-dione (dimedone) in acetic acid...     

Catalytic Access to Chiral δ-Lactams via Nucleophilic Dearomatization of Pyridine Derivatives

Nitrogen-bearing rings are common features in the molecular structures of modern drugs, with chiral δ-lactams being an important subclass due to their known pharmacological properties. Catalytic dearomatization of preactivated pyridinium ion derivatives emerged as a powerful method for the rapid construction of chiral N-heterocycles. However, direct catalytic dearomatization of simple pyridine derivatives are scarce and methodologies yielding chiral δ-lactams are yet to be developed. Herein, we describe an enantioselective C4-dearomatization of methoxypyridine derivatives for the preparation of functionalised enantioenriched δ-lactams using chiral copper catalysis. Experimental ¹³C kinetic isotope effects and density functional theory calculations shed light on the reaction mechanism and the origin of enantioselectivity.