One‐Pot Halogen‐Free Synthesis of 2,3‐Dihydro‐1H‐inden‐2‐yl‐phosphinic Acid from 1H‐indene and Elemental Phosphorus via the Trofimov–Gusarova Reaction

1H‐Indene reacts with red phosphorus in the superbasic KOH/DMSO(H₂O) suspension at 120°C for 2.5 h to give (after acidification) 2,3‐dihydro‐1H‐inden‐2‐yl‐phosphinic acid in 55% isolated yield.     

The Darboux problem for an implicit fractional-order differential equation

We obtain the sufficient conditions of the existence and uniqueness of a solution of the Darboux problem for an implicit fractional-order differential equation. A numerical method of solution of this problem is proposed.     

Green and efficient synthesis of pyrazolo[3,4‐b]quinolin‐5‐ones derivatives by microwave‐assisted multicomponent reaction in hot water medium

Novel simple, efficient, and eco‐friendly synthetic procedure for preparation of pyrazolo[3,4‐b]quinolin‐5‐ones based on three‐component microwaves‐assisted heterocyclization reaction of 5‐aminopyrazoles, aromatic aldehydes, and dimedone in hot‐water medium was developed. The new method allows obtaining target heterocycles in good and excellent yields and with high degree of purity. J. Heterocyclic Chem., (2011).     

Study of spontaneous E/Z isomerization of bis[(Z)‐cyanomethylidene]‐diazapentacyclodienedicarboxylates by 1H, 13C,and 15N NMR spectroscopy,X‐ray,and quantum chemical calculation data

X‐ray data show that the diethyl 6,13‐bis[(Z)‐cyanomethylidene]‐5,5,14,14‐tetramethyl‐4,15‐dioxa‐7,12‐diazapentacyclo[9.5.2.0^2,10.0^3,7.0^12,16]octadeca‐8,17‐diene‐10,17‐dicarboxylate is formed as the ZZ isomer and diastereomer with the (1R*,2R*,3R*,10S*,11R*,12R*,16R*) configuration. The ¹H, ¹³C, and ¹⁵N NMR data exhibit that on standing in chloroform‐d solution, there is a spontaneous isomerization of this compound resulting in a thermodynamically stable mixture of the ZZ, ZE, EE, and EZ isomers with the same backbone. Using the 2D [¹H–¹H] COSY, [¹H–¹³C] HSQC, and [¹H–¹³C, ¹H–¹⁵N] HMBC NMR techniques and quantum chemical calculations makes it possible a complete assignment of signals in the ¹H, ¹³C, and ¹⁵N NMR spectra of each of the isomers. Such isomerization does not occur for similar compounds with the more bulky substituents at the 1,3‐oxazolidine rings. Copyright © 2016 John Wiley & Sons, Ltd.     

Three-Component synthesis and characterization of nicotinamide derivatives containing a buta-1,3-diene-1,1,3-tricarbonitrile fragment

The synthesis of nicotinamide derivatives containing a buta-1,3-diene-1,1,3-tricarbonitrile fragment through the base-promoted three-component reaction of an aromatic aldehyde, an acetoacetamide and malononitrile dimer in the presence of an oxidant is reported. The HOMO-LUMO energy levels were estimated by cyclic voltammetry and UV-Vis measurements. The influence of aryl and carbomoyl substituents on the optical and electrochemical properties was also investigated.     

Mechanically Assisted Bioluminescence with Natural Luciferase

Mechanochemical analogues have recently been established for several enzymatic reactions, but they require periodic interruption of the reaction for sampling, dissolution, and (bio)chemical analysis to monitor their progress. By applying a mechanochemical procedure to induce bioluminescence analogous to that used by the marine ostracod Cypridina (Vargula) hilgendorfii, here we demonstrate that the light emitted by a bioluminescent reaction can be used to directly monitor the progress of a mechanoenzymatic reaction without sampling. Mechanical treatment of Cypridina luciferase with luciferin generates bright blue light which can be readily detected and analyzed spectroscopically. This mechanically assisted bioluminescence proceeds through a mechanism identical to that of bioluminescence in solution, but has higher activation energy due to being diffusion‐controlled in the viscous matrix. The results suggest that luciferases could be used as light‐emissive reporters of mechanoenzymatic reactions.     

P–C Bond Cleavage by Hydroxyl Function during the Addition of Tris(2‐pyridyl)phosphine to Cyanopropargylic Alcohols in Water

The addition of tris(2‐pyridyl)phosphine to tertiary cyanopropargylic alсоhols in water (room temperature, no catalyst, 5 h) is accompanied by elimination of pyridine to give cyanoallyldipyridylphosphinates of E‐configuration in 60–73% yield, thus indicating the oxygen insertion of the hydroxyl group into the P C bond of the intermediate (Z)‐alkenyldipyridylphosphine oxide.