General non-catalytic approach to spiroacenaphthylene heterocycles: multicomponent assembling of acenaphthenequinone,cyclic CH-acids and malononitrile

The new type of non-catalytic cascade reaction was found: the direct multicomponent reaction of acenaphthenequinone, cyclic CH-acids, and malononitrile to form spiroacenaphthylene heterocycles. The direct heating in water acenaphthenequinone, cyclic CH-acids, and malononitrile at 80 °C results in the formation of spiroacenaphthylene heterocycles in 90–95% yields. Thus, a new simple and efficient green ‘one-pot’ method to synthesize substituted spiroacenaphthylene frameworks was found directly from simple starting compounds. The application of this convenient green multicomponent method is also beneficial from the viewpoint of diversity-oriented large-scale processes.     

Cascade assembly of N,N′-dialkylbarbituric acids and aldehydes: a simple and efficient one-pot approach to the substituted 1,5-dihydro-2H,2′H-spiro(furo[2,3-d]pyrimidine-6,5′-pyrimidine)-2,2′,4,4′,6′(1′H,3H,3′H)-pentone framework

Cascade assembly of N,N′-dialkylbarbituric acids and aldehydes in the presence of bromine leads to the selective and efficient formation of substituted 1,5-dihydro-2H,2′H-spiro(furo[2,3-d]pyrimidine-6,5′-pyrimidine)-2,2′,4,4′,6′-(1′H,3H,3′H)-pentones in 70-88% yields via a complex cascade process. Spirobarbiturates containing the furo[2,3-d]pyrimidine framework are a class of compounds with interesting pharmacological and physiological activity.     

Quantum-inspired resonance for associative memory

A new kind of dynamics for simulations based upon quantum-classical hybrid is discussed. The model is represented by a modified Madelung equation in which the quantum potential is replaced by different, specially chosen potentials. As a result, the dynamics attains both quantum and classical properties: it preserves superposition and entanglement of random solutions, while allowing one to measure its state variables using classical methods. Such an optimal combination of characteristics is a perfect match for quantum-inspired information processing. In this paper, the retrieval of stored items from an exponentially large unsorted database is performed by quantum-inspired resonance using polynomial resources due to quantum-like superposition effect.     

catena‐Poly­[[tetrakis(2‐allyl­tetrazole‐κN4)‐tetra‐μ‐chloro‐tricopper(II)]‐di‐μ‐chloro]

In the crystal structure of the title compound, [Cu₃Cl₆(C₄H₆N₄)₄]_n, there are three Cu atoms, six Cl atoms and four 2‐allyl­tetrazole ligands in the asymmetric unit. The polyhedron of one Cu atom adopts a flattened octahedral geometry, with two 2‐allyl­tetrazole ligands in the axial positions [Cu—N4 = 1.990 (2) and 1.991 (2) Å] and four Cl atoms in the equatorial positions [Cu—Cl = 2.4331 (9)–2.5426 (9) Å]. The polyhedra of the other two Cu atoms have a square‐pyramidal geometry, with three basal sites occupied by Cl atoms [Cu—Cl = 2.2487 (9)–2.3163 (8) and 2.2569 (9)–2.3034 (9) Å] and one basal site occupied by a 2‐allyl­tetrazole ligand [Cu—N4 = 2.028 (2) and 2.013 (2) Å]. A Cl atom lies in the apical position of either pyramid [Cu—Cl = 2.8360 (10) and 2.8046 (9) Å]. The possibility of including the tetrazole N3 atoms in the coordination sphere of the two Cu atoms is discussed. Neighbouring copper polyhedra share their edges with Cl atoms to form one‐dimensional polymeric chains running along the a axis.     

Multicomponent Synthesis of 2-(2,4-Diamino-3-cyano-5H-chromeno[2,3-b]pyridin-5-yl)malonic Acids in DMSO

Dimethyl sulfoxide is a widely used solvent in organic synthesis and in the pharmaceutical industry because of its low cost, stability, and low toxicity. Multicomponent reactions are an advanced approach that has become an efficient, economical, and eco-friendly substitute for the conventional sequential multi-step synthesis of various biologically active compounds. This approach was adopted for the synthesis of previously unknown 2-(2,4-diamino-3-cyano-5H-chromeno[2,3-b]pyridin-5-yl)malonic acids via transformation of salicylaldehydes, malononitrile dimer, and malonic acid. It was shown that the use of DMSO at room temperature makes it possible to synthesize previously unavailable compounds. The investigation of the reaction mechanism using ¹H-NMR monitoring made it possible to confirm the proposed mechanism of the transformation. The structure of synthesized 5H-chromeno[2,3-b]pyridines was confirmed by 2D-NMR spectroscopy.     

Electrocatalytic Fast and Efficient Multicomponent Approach to Medicinally Relevant (2‐Amino‐4H‐chromen‐4‐yl) phosphonate Scaffold

‘One‐pot’ electrocatalytic transformation of salicylaldehydes, malononitrile, and triethyl phosphite in an undivided cell results in the formation of diethyl (2‐amino‐3‐cyano‐4H‐chromen‐4‐yl)phosphonates in 88–93% substance yields and 880–930% current efficiency via complex multicomponent process. This novel electrocatalytic chain process opens an effective, fast, and convenient way to cyano‐functionalized (2‐amino‐4H‐chromen‐4‐yl)phosphonate systems which are promising compounds for biomedical applications. This efficient electrocatalytic approach to the (2‐amino‐4H‐chromen‐4‐yl)phosphonate scaffold represents novel synthetic concept for multicomponent reactions (MCR) strategy and allows to combine the synthetic virtues of conventional MCR with ecological benefits and convenience of facile electrocatalytic procedure.     

Heterogenization of metalorganic catalysts of olefin polymerization and evaluation of active site non-uniformity

Heterogenized activators - “support-H₂O/AlR₃” (where R=Me, iBu, support=montmorillonite, zeolite), synthesized directly on the support, form with metallocenes metal alkyl complexes highly active in olefin polymerization without the use of commercial methylaluminoxane (MAO). It was shown by the method of temperature programmed desorption with the application of mass-spectrometry (TPD-MS) that the aluminumorganic compound in support-H₂O/AlR₃ is in general similar to the structure of commercial MAO. The heterogenization of Zr-cenes on support-H₂O/AlR₃ is accompanied by the appearance of the energy non-uniformity of active sites. The activation energy of thermal destruction of active Zr-C bonds in the active sites of prepared catalysts changes in the range from 25 to 32 kcal/mol.