With the expansion of the scope of lubricant oils and fuels, the requirements for their performance properties are increasing. One of the performance characteristics of these petroleum products is their oxidation resistance. It is known that as a result of oxidation, their performance properties deteriorate. Antioxidant stabilizers are used to increase the resistance of organic materials against oxidation. The study of the mechanism of action of oxidation inhibitors is one of the most important tasks in this field, the solution of which is the creation of a theoretically substantiated approach to the targeted synthesis of more effective antioxidants. To create the theoretical and practical foundations of solving this problem was to find novel classes of effective additives of multivalent activity, particularly antioxidants, a series of recently synthesized nitrogen, sulfur, selenium and phosphorus polyfunctional compounds, including pyrroledithioates, 6,8-bicycloctanes, aminopyrimidine, tris(2-pyridyl)phosphinesulfide and -selenide have been investigated using model oxidative reactions. The compounds studied appear to be perspective inhibitors of hydrocarbon oxidation. Some of them are antioxidants of combined action, breaking the chains of the oxidative reactions with cumene peroxide radicals and catalytically decomposing cumene hydroperoxide.

In order to obtain sulfur-containing organophosphorus compounds that are promising as extractants of heavy metals, the interaction of elemental phosphorus and sulfur with alkyl bromides catalyzed using strong bases was studied. According to the task, the reaction of non-toxic and non-flammable red phosphorus with alkyl bromides under conditions of phase transfer catalysts (PTC), followed by the introduction of elemental sulfur into the reaction medium, were studied. It is shown that alkyl bromides interact with red phosphorus when heated (95–105 °C, 5–8 h) under conditions of phase transfer catalysts (PTC) in a two-phase system: a 60% aqueous solution of KOH-toluene-benzyltriethylammonium chloride (BTEAC) forming a mixture of organophosphorus compounds along with alkylphosphines (57–60%), are the main reaction products; alkylphosphine oxides are also formed (40–43%). The introduction of elemental sulfur (solution in toluene) at the final stage of the process into the reaction mass cooled to 40–60 °C leads to the expected alkylphosphine sulfides, which are the result of the interaction of alkylphosphines with sulfur. The formation of complex mixtures of products prevents the release of target alkylphosphine sulfides in individual form. However, the synthesized mixture of alkylphosphine sulfides and alkylphosphine oxides without separation into individual components is promising for studying its extraction properties in relation to heavy metals. Testing of the extraction properties of synthesized mixtures of alkylphosphine sulfides and alkylphosphine oxides in relation to heavy metals (Ni, Co, Zn, Pb) and noble metals (Ag) showed that the resulting mixtures of tertiary phosphine oxides and phosphine sulfides are highly effective extractants. The degree of extraction in relation to Ni, Co, Zn, and Pb varies from 99.90 to 99.99%, and for Ag from 99.56 to 99.59%.

Polyfluoroalkyl dichlorophosphites reacted with propargyl alcohol in Et3N/hexane to give di(2-propynyl) polyfluoroalkyl phosphites, which are transformed into polyfluoroalkyl 2-propynyl allenylphosphonates and isomeric (1-propynyl)phosphonates upon storage.

Alkylphosphinic acids, including long-chain ones, were synthesized in up to 76% yields from red phosphorus and n-AlkBr (Alk = C4–C14) under micellar catalysis conditions. The reaction proceeds efficiently and chemoselectively upon heating (85–90°C, 6 h) in a KOH/H2O/toluene/cetyltrimethylammonium bromide system.

In this study, a series of nitrogen-based novel heterocyclic compounds were synthesized and characterized by elemental analysis, IR and NMR spectra. The novel synthesized nitrogen-based novel heterocyclic compounds were evaluated against the acetylcholinesterase (AChE) and alpha-glycosidase enzymes. These compounds showed IC50 values in range of 0.76-28.04 mu M against AChE as a cholinergic enzyme, and 26.10-82.17 mu M against alpha-glycosidase as a hydrolytic enzyme. On the other hand, they demonstrated K(i )values between 1.25 +/- 0.22-25.36 +/- 4.72 mu M against AChE, and 25.07 +/- 4.57-78.55 +/- 17.04 mu M against alpha-glycosidase enzymes. The synthesized nitrogen-based novel heterocyclic compounds exhibited effective inhibition profiles against both indicated metabolic enzymes. These results may contribute to the development of new drugs particularly to treat some disorders, which widespread display in the world including Alzheimer's disease and diabetes. Furthermore, molecular docking calculations were made to compare the theoretical biological activities of nitrogen-based novel heterocyclic compounds against proteins including enzymes. After these calculations, ADME/T analysis was performed to examine the drug properties of nitrogen-based novel heterocyclic compounds.

Long-chain n-Alkylphosphonic acids, AlkP(O)(OH)(2), are synthesized in up to 91 % yield (mostly 40-60 %) by straightforward phosphonylation of alkyl bromides (AlkBr, Alk=C-4-C-18) with red phosphorus (P-n) in the multiphase KOH/H2O/toluene system in the presence of 2-10 mol % of cetyltrimethylammonium bromide (CTAB), acting as a micellar/phase transfer catalyst and as a generator/transporter of superbasic hydroxide anions, the intermediate potassium phosphinates being in situ oxidized/neutralized by nitric acid. The key steps of the phosphonylation mechanism are the P-P bond cleavage of P-n polymeric molecules by superbasic -OH anions, dissolved in the CTAB micelles, and phase transfer of polyphosphide anions to the organic phase and their alkylation with AlkBr.

Terminal acylacetylenes act as trimodal auxiliaries in SHN cross-coupling of pyridines with phosphine chalcogenides. The reaction proceeds via phosphorylation of the pyridine 2 position followed by 2 → 4-migration of phosphoryl moieties.

Long-chain n-alkyl-H-phosphinic acids (Alk = C4-C18) are chemoselectively synthesized in yields up to 90% via the direct one-pot alkylation/oxidation of red phosphorus (Pn) in the multi-phase alkyl bromide/KOH/H2O/toluene system with alkyl-PEG recyclable micellar catalysts, which demonstrate good recyclability.

The possibility and prospects of using tertiary phosphine sulfides synthesized on the basis of on affordable and secondary raw materials as effective extractants of heavy metals have been investigated

Reactions between 3-phenyl-2-propynenitrile, secondary phosphine oxides and pyridinoids have been implemented and studied. Pyridine and isoquinoline react with propynenitrile and phosphine oxides at room temperature according to the N-vinylation/C-phosphorylation scheme to afford (Z)-N-(2-cyano-1-phenyl)ethenyl phosphoryl-1,4-dihydropyridines or -1,2-dihydroiso quinolines. In the case of pyridine on heating (80–85 °°°C), the reaction gives 4-phosphorylpyridines (SNHAr reaction) and 3-phenyl-acrylonitrile oligomers.

The catalyst- and solvent-free reaction between bis(fluoroalkyl) phosphonates and aldimines occurs under mild conditions (20–22 °C, 0.25–4 h) to afford a new family of α-amino polyfluoroalkylphosphonates in up to quantitative yields.

Quinolines undergo catalyst-free double CH-functionalization upon treatment with secondary phosphine oxides (70-75 °C, 20-48 h) followed by oxidation of the intermediate 2,4-bisphosphoryltetrahydroquinolines with chloranil. The yields of the target 2,4-bisphosphorylated quinolines are up to 77%. Thus, a double-SNHAr reaction sequence in the same molecule of quinoline has been realized. In the case of 2,4-bisphenylphosphoryltetrahydroquinolines, the aromatization occurs with elimination of one molecule of diphenylphosphine oxide to afford the products of monofunctionalization, 4-diphenylphosphorylquinolines, in 40-45% yields.

Diverse mercerized celluloses (powder cellulose and kraft pulp) have been successfully vinylated with acetylene in an aqueous solution of alkali metal hydroxides (KOH or NaOH) at 125–140 °C. Depending on the reaction conditions, degree of substitution (DS) of the hydroxyl groups by highly reactive polymerazable vinyloxy groups ranges 0.08–0.73, the yields of vinyl celluloses being 24–75%. The process is accompanied by alkaline degradation of the cellulose macromolecule.

Two ways for the synthesis of new representatives of non-symmetric organic phosphites with polyfluoroalkyl substituents were developed based on organic dichlorophosphites. The reaction of polyfluoroalkyl dichlorophosphites with allyl alcohol, proceeding at a temperature of –10–22°C (2 h) in the presence of triethylamine, gave diallyl polyfluoroalkyl phosphites in a yield of 75–77%. Under similar conditions (–30–22°C, 2–4 h, Et 3 N), alkyl (or aryl) dichlorophosphites reacted with polyfluoroalkanols to form alkyl (or aryl) bis(polyfluoroalkyl) phosphites (yield 56–67%). Unlike diallylpolyfluoroalkyl- and alkylbis(polyfluoroalkyl) phosphites, arylbis(polyfluoroalkyl) phosphites are symmetrized under storage conditions (room temperature, inert atmosphere), forming the corresponding triaryl- and tris(polyfluoroalkyl) phosphites.

Ferrocenylalkyl vinyl ethers undergo a facile rearrangement (CH2Cl2, 20-25 degrees C, 0.5 h) in the presence of 3-4 mol% PdCl2(MeCN)(2), to give the corresponding ferrocenyl alkanals or alkanones in high yields. Yttrium and lanthanide triflates and Lewis acids (AlCl3) were less effective as catalysts. (C) 2020 Elsevier Ltd. All rights reserved.

Isoquinolines react with secondary phosphine oxides without catalyst (70–75 °C, 10–15 h, without solvent or in MeCN) to chemo- and regioselectively form previously unknown diadducts, 1,3-bis(diorganylphosphoryl)-1,2,3,4-tetrahydroisoquinolines, in high yields (85–95%).

Cysteamine (2-aminoethanethiol) undergoes oxidative cross-coupling with secondary phosphine sulfides and phosphine selenides under mild conditions (room temperature, 2–5 h, CCl4/Et3N) to give products of monocoupling at the amino group (ethylchalcogenophosphinic amides with free SH functions) and dicoupling (l-chalcogenophosphorylamino-2-chalcogenothioethanes) in 72–85% total yield. Under similar conditions, stirring an equimolar mixture of bis(2-phenylethyl)phosphine sulfide (or selenide), 1-butylamine, and 1-butanethiol leads to the chemoselective formation of the corresponding chalcogenophosphinic amides in high yield.