Room temperature MgI2-catalyzed Friedel–Crafts reaction between electron-rich (het)arenes and ethyl glyoxylate

Magnesium iodide-catalyzed addition of electron-rich (het)arenes to ethyl glyoxylate proceeds at room temperature with high chemoselectivity to afford ethyl 2-(het)aryl- 2-hydroxyacetates in yields up to 95%.     

Catalyst-Free Arylation of Tertiary Phosphines with Diaryliodonium Salts Enabled by Visible Light

The visible-light-induced arylation of tertiary phosphines with aryl(mesityl)iodonium triflates to produce the quaternary phosphonium salts occurs under mild, metal, and catalyst-free conditions. Photo-excited EDA complexes between diaryliodonium salts and phosphines supposedly enable this transformation, which is difficult to achieve through the traditional ground-state reactions. Demonstrating high functional group tolerance, broad scope, and complete selectivity of the aryl group transfer, the method is particularly compatible with sterically congested phosphines, which are challenging under metal-based catalytic methods.     

Self‐Assembled Silver–Gold Nanoisland Films on Glass for SERS Applications

We present a study of resonant optical properties of gold‐protected silver nanoisland films. Silver nanoislands were grown on a glass substrate using out‐diffusion technique, the growth was followed by the deposition of nanometer‐thick gold coatings. Scanning electron microscopy and optical spectroscopy were used to characterize morphology and extinction spectra of the grown combined silver–gold nanostructures. Micro Raman spectroscopy of the combined nanoislands has demonstrated their signal enhancement factor exceeding that one of the initial silver nanoislands.     

Aminohydroxypropane Esters of Hydroxyethylidenebisphosphonic Acid

Abstract

The 1-hydroxyethylidene-1,1-bisphosphonic acid (HEDP) (I) reacts with epichlorohydrine (II) and aminoepoxypropanes (III) in water. Optimum pH for the esterefication is 6–7. The reaction completes in 20–30 h on 60°C at this pH and leads to the mixture of the original HEDP with the mono- and diesters. The mixture of di-Na salts of HEDP and the monochloroester (IV) in ratio 1:1.7 was precipitated from the reaction solution on using of the epichlorohydrine (II). This mixture was used for synthesis of aminoesters (VI a,b) unavailable by direct reaction of HEDP with corresponding aminoepoxides.     

Signature codes for noisy multiple access adder channel

We prove new lower bounds on the rate of codes for noisy multiple access adder channel and discuss its application to the well-known coin weighing problem in the case when some measurements are incorrect.     

Synthesis of 5,10,15,20-tetra[6' -nitro-1,3,3-trimethylspiro- (indolino-2,2' -2H-chromen-5-yl)]porphyrin and its metal complexes

A new 5,10,15,20-tetrasubstituted porphyrin containing four 6’-nitro-1,3,3-trimethylspiro(indolino-2,2’-2H-chromene) substituents and its complexes with Zn²⁺ and Cu²⁺ ions were prepared and characterized by physicochemical methods of analysis.