3-Methoxycarbonyl-4-phenyl-2-pyrrolidone in reactions with benzalmalonate and its analogs

3-Methoxycarbonyl-4-phenyl-2-pyrrolidone reacts with benzalmalonate and related compounds as an N-nucleophile affording adducts as an easily resolvable diastereoisomeric mixture. Structure of the synthesized compounds is studied by IR and ¹H, ¹³C NMR spectroscopy. Structural parameters and configurations of the stereoisomers of one among the series of synthesized compounds was determined by X-ray structural analysis. The pyrrolidone ring of these compounds is shown to be present in an envelope conformation. The supramolecular structures in crystal are formed mainly on account of intermolecular hydrogen bonds of C-H?O type and π?π interactions.

     

Carboxylate phosphabetaines based on tertiary phosphines and unsaturated dicarboxylic acids

By reaction of triorganylphosphines with unsaturated dicarboxylic acids adducts of betaine structure were synthesized whose stability depended on the character of substituents at phosphorus and on the structure of acid. The betaine obtained from phosphines and maleic and fumaric acids redily underwent decarboxylation into the corresponding monoacyl phosphonium derivatives. The structure of the latter was established by means of X-ray crystallography. The adduct prepared from phosphines and itaconic acid was stabilized by intramolecular hydrogen bond between the acylate anionic center and the “second” carboxy group.     

A “sodium trap” based on benzo-15-crown-5 with an exocyclic N-(thiophosphoryl)thiourea moiety

For N-(thio)phosphorylthioureas of the common formula RC(S)NHP(X)(OiPr)₂HL^I (R = N-(4′-aminobenzo-15-crown-5), X = S), HL^II (R = N-(4′-aminobenzo-15-crown-5), X = O), HL^III (R = PhNH, X = S), HL^IV (R = PhNH, X = O), and (N,N′-bis-[C(S)NHP(S)(OiPr)₂]₂-1,10-diaza-18-crown-6) H₂L^V, salts LiL^I,III,IV, NaL^I–IV, KL^I–IVM₂L^V (M = Li⁺, Na⁺, K⁺), Ba(L^I,III,IV)₂, and BaL^V have been synthesized and investigated. Compounds NaL^I,II quantitatively drop out as a deposit in ethanol medium, allowing the separation of Na⁺ and K⁺ cations. This effect is not displayed for the other compounds. The crystal structures of HL^III and the solvate of the composition [K(Me₂CO)L^III] have been investigated by X-ray crystallography.     

Synthesis and molecular structure of alloocimene adducts with maleic and citraconic anhydrides

Reactions of alloocimene with maleic and citraconic anhydrides gave the corresponding Diels-Alder cycloaddition products which may be regarded as new synthetic sesquiterpenoids. The molecular structures of the adducts, determined by X-ray analysis, indicated endo addition of the dienophiles at the most sterically accessible diene system and syn-boat conformation of the bicyclic skeleton.     

Reactions of 1,3,5-triazinylnitroformaldoximes 3*. Interaction of 1,3,5-triazinylnitroformaldoximes with malonic acid esters

The reaction of 6-R-4-methoxy-1,3,5-triazin-2-ylnitroformaldoximes with dimethyl malonate gives the zwitterionic 4-methoxycarbonyl-3-(4-R-6-methoxy-1,3,5-triazin-2-yl)-4,5-dihydroisoxazol-5-ones. X-ray structural analysis has been carried out on the zwitterionic 4-methoxycarbonyl-3-(4-methoxy-6-piperidino-1,3,5-triazin-2-yl)-4,5-dihydroisoxazol-5-one.     

Crystal structure of cyclic sulfin- and sulfonamides of the thiazine series: Conformation,intra- and intermolecular interactions

An X-ray crystallographic study of a new compound is performed and the structure of five sulfin- and sulfonamides of the thiazine series is discussed. The conformation of the thiazine ring in all structures (a distorted boat) is stabilized by the intramolecular interaction of the C-H…N type. The nitrogen atom of the thiazine ring has a pyramidal configuration. The geometry of isolated molecules is calculated at density functional theory level (PBE1PBE, 6-31G(d,p)) and compared to that observed in the crystals. In the crystal structures different packing motifs are implemented with the formation of supramolecular associates of different types due to classical hydrogen bonds such as N-H…O.     

New Functional Cyclic Aminomethylphosphine Ligands for the Construction of Catalysts for Electrochemical Hydrogen Transformations

Eight‐membered cyclic functional bisphosphines, namely 1,5‐di‐aryl‐3,7‐di(2‐pyridyl)‐1,5‐diaza‐3,7‐diphosphacyclooctanes (aryl=2‐pyridyl, m‐tolyl, p‐tolyl, diphenylmethyl, benzyl, (R)‐(+)‐(α‐methyl)benzyl), with 2‐pyridyl substituents on the phosphorus atoms have been synthesized by condensation of 2‐pyridylphosphine, formaldehyde, and the corresponding primary amine. The structures of some of these bisphosphines have been investigated by X‐ray crystallography. The bisphosphines readily form neutral P,P‐chelate complexes [(κ²‐P,P‐L)MCl₂], cationic bis‐P,P‐chelate complexes [(κ²‐P,P‐L)₂M]²⁺, or a five‐coordinate complex [(κ²‐P,P‐L)₂NiBr]Br. The electrochemical behavior of two of the nickel complexes, and their catalytic activities in electrochemical hydrogen evolution and hydrogen oxidation, including the fuel‐cell test, have been studied.