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The η2-formyl borane system 3 is readily available by carbonylation of the vicinal P/BH frustrated Lewis pair (FLP) 1. It serves as a frustrated C/B Lewis pair toward carbon dioxide or phenylisocyanate. In the presence of B(C6F5)3, it forms the coupling product between two CO-derived units. The resulting compound 13 rearranged to a doubly O-borylated endiolate, with both of the central carbon atoms originating from carbon monoxide. The subsequent treatment with a silane gave a rare macrocyclic silicon endiolate.

The reaction of equimolar amounts of pyridoxal and 1,2-propylenediamine leads to the formation of monoimine, which exists as a cyclic imidazolidine tautomer. The latter reacts with aromatic aldehydes to form unsymmetric bisazomethines. The reaction of azomethine with phenylisocyanate produces a compound containing a carbamate group, and the reaction with hydrochloric acid leads to the formation of a salt-based furopyridine.

The kinetics of urethane formation during interaction of phenylisocyanate with hydroxyl-containing oligomers in the presence of shungite was researched using the method of IR spectroscopy. The constants of the reaction rate were determined by kinetic curves plotted in coordinates of a second order equation. The kinetics of curing of polyurethane compositions of “cold” curing, modified by shungite, was studied using the method of rotational rheometry and it was shown that the presence of the latter leads to acceleration of the curing process.

Hydroxyl-terminated telechelic polyisobutylene (PIB) was prepared through living cationic polymerization. A living PIB chain was formed using the t-Bu-m-DiCuOMe/TiCl4 initiating system and then capped with 1,3-butadiene (BD) to prepare chlorine-terminated telechelic PIB. The chlorine-terminated telechelic PIB was then hydrolysed with tetrabutylammonium hydroxide to form hydroxyl-terminated PIB. Nuclear magnetic resonance spectroscopy confirmed hydrolysis completion. The hydroxyl-terminated PIB was subsequently used as a diol to react with 4,4-methylenebis(phenylisocyanate) (MDI) and produce a PIB-based polyurethane, which showed stronger acid resistance, hydrolysis stability and thermal oxidation stability than a commercial polyurethane.

A series of new heteroleptic alkaline earth (Ae) metal complexes of general formula [{(Ph2CHNCH)2C4H2N}AeI(THF)3] {Ae = Ca (2), Sr (3), and Ba (4)} were synthesized via salt metathesis by reacting potassium salt of ligand 1-K [{(Ph2CHNCH)2C4H2N}K(THF)2] with anhydrous alkaline earth metal diiodides (AeI2). The homoleptic calcium and barium complexes [{(Ph2CHNCH)2C4H2N}2Ae] [Ae = Ca (5), Ba (6)] were prepared by treating metal bis-hexamethyldisilazide [Ae{N(SiMe3)2}2(THF)2] with the protic ligand 1-H [(Ph2CH–NCH)2C4H2NH] in a 1 : 2 molar ratio. Calcium complex 5 was used as an active pre-catalyst for the addition of N–H bond of arylamines across the heterocumulenes such as phenylisocyanate (PhNCO) and phenylisothiocyanate (PhNCS) under neat conditions, and up to 99% yields of the corresponding urea and thiourea derivatives were obtained.

We synthesized and characterized the novel olefinic multidentate actor ligand dbap-py. The ligand consists of a 2-methyl pyridine unit and an azepine component fused by an N-alkylation. The coordin...

The Michael addition of enaminoesters to coumarins leads to the formation of the rearranged adduct 1 whose structure has been previously elucidated by X-ray crystallographic analysis. Now, N- and/or O-carbamoylation of the 6-amino-2-pyridone 1 by treatment with phenyl isocyanate in a molar ratio of 1:1 and 1:2 gave N-mono- (2a) or N,O-bis-(phenylcarbamoyl) (3) derivatives, respectively. Further transformations of the corresponding new 2-pyridone derivative 2a into the O-acetyl derivative 2b and the chromeno[3,4-c]pyridine 4 are reported as well.

The gas-phase extrusion-insertion reactions of the copper complex [bathophenanthroline (Bphen)CuI (O2 CC6 H5 )]2- , generated via electrospray ionization, was studied in a linear ion trap mass spectrometer with the combination of collision-induced dissociation (CID) and ion-molecule reaction (IMR) events. Multistage mass spectrometry (MSn ) experiments and density functional theory (DFT) demonstrated that extrusion of carbon dioxide from [(Bphen)Cu(O2 CC6 H5 )]2- (CID) gives the organometallic intermediate [(Bphen)Cu(C6 H5 )]2- , which subsequently reacts with carbon disulfide (IMR) via insertion to yield [(Bphen)Cu (SC(S)C6 H5 )]2- . The fragmentation of the product ion resulted in the formation of [Bphen]2- , [(Bphen)Cu]- and C6 H5 CS2 - under CID conditions. The formation of the latter two charge separation products thus provides evidence of C-C bond formation in the IMR step. Although analogous studies with isocyanate, which is isoelectronic with CS2 , showed a poor reactivity in the gas phase, the mechanistic understanding obtained from these model studies encourages future development of a solution phase protocol for the synthesis of amides from carboxylic acids and isocyanates mediated by copper(I) complexes.

Semi-rigid polyurethane (PU) films based on functionalized liquid natural rubber (FLNR) were prepared by one-shot and two-shot methods. FLNR derived from waste crumb rubber acted as the soft segment and the hard segment consisted of 4,4′-methylenebis-(phenylisocyanate) (MDI) and 1,4-butanediol (BDO). The urethane linkage formation was confirmed by FTIR with a –NH-peak at 3317 cm−1 and disappearance of the NCO peak at 2295 cm−1. The semi-rigid PU with low rubber polyol chain favored solubility in non-polar solvent (toluene and chloroform) and low polar solvent (THF). For semi-rigid PU with high rubber polyol chain, it was poorly soluble in any solvent thus it has high stability. Studies on the hydrolytic stability were shown to be highly influenced by the high rubber polyol chain (soft segment contents more than 60%) in semi-rigid PU composition. The thermal stability of semi-rigid PU as determined by thermogravimetric analyses (TGA) showed improved degradation stabilities (more than 270 °C) in the presence of BDO and higher molecular weight of FLNR.

Trimethyl(N-morpholino)silane (Me3SiMorph) and dimethyl-di(N-morpholino)silane (Me2SiMorph2) were synthesised. The insertion reactions of both silanes with CO2, n-butylisocyanate (nBuNCO), phenylisocyanate (PhNCO), methylisothiocyanate (MeNCS), n-butylisothiocyanate (nBuNCS) and phenylisothiocyanate (PhNCS) into the Si–N-bond were investigated. One CO2 molecule inserts into each Si–N-bond forming carbamoylic moieties. The insertion reaction of isocyanates depends on the organic substituents bound to the heteroallene unit. PhNCO inserts twofold forming a biuret moiety, while nBuNCO yields urea units by insertion of just one molecule per Si–N-bond. The isothiocyanates are less reactive forming thiourea moieties. Aliphatic isothiocyanates furnish equilibria between the reactants and the insertion product at room temperature. All products have been characterized by spectroscopic methods. Single crystal X-ray diffraction analyses of five insertion products have been performed. The observed reactivity is discussed on the basis of NBO charges and calculated Gibbs free energies of the insertion reactions.

Polyurethane nanofibers functionalized by high amount of N-chloro hydantoin were prepared for the decontamination of chemical warfare agents. Azido-polyurethane was firstly synthesized using azido-polydiol with 4,4′-methylenebis(phenylisocyanate) and 1,4-butanediol via step-addition polymerization. Hydantoin was introduced into the polyurethane via click reaction, followed by electrospinning and chlorination to obtain the decontaminable fibers. This N-chlorinated hydantoin-polyurethane fiber is an active decontaminable species for 2-chloroethyl ethyl sulfide and demeton-S-methyl, the simulant of chemical warfare agent. The decontamination efficiency of each exhibits 69% and 16% for 2-chloroethyl ethyl sulfide and demeton-S-methyl, respectively, with molar ratio of 1/1 for 2 h at ambient condition. This N-chlorinated hydantoin-polyurethane fiber exhibited considerable potential as the decontaminable material against toxic chemical warfare agents.

The supported ionic liquid phase (SILP) technology has been used to immobilize Candida Antarctica Lipase B (CALB) within a hybrid monolith. The monolith was synthesized in situ inside a Teflon® cartridge via the 4-(dimethylamino)pyridine-catalyzed polyaddition of 1,1,1-tris(hydroxymethyl)propane to 4,4′-methylenebis(phenylisocyanate) in the presence of porous cellulose-2.5-acetate beads. An ionic liquid containing small amounts of CALB was impregnated into these beads and the resulting enzyme-SILP (e-SILP) catalyst was tested in the continuous gas-phase transesterification of vinyl propionate and 2-propanol. The enzyme was catalytically active with conversions exceeding 30% at short contact times of only 24 s. Total turn-over numbers of 1.7 × 108 and 2.4 × 108 molsubstrate molCALB−1 could be obtained for the two e-SILP cartridges tested. High stability could be achieved at relatively high reaction temperatures around 65 °C for more than 700 h time on stream.

A new single-stage synthesis of betulin phenylcarbamates is suggested that uses 1-phenylurea as a reagent for betulin O-carbamoylation. A chemoselectivity of hydroxyl-groups in carbamoylation of betulin with 1-phenylurea appeared to occur. Synthesized nitrogen-containing betulin derivatives - phenylcarbamates are valuable as bioactive substances.

Reactions of (4-methoxyphenyl)amine and its trimethylsilyl derivative with organosilicon isocyanates and phenylisocyanate have been studied. (4-Methoxyphenyl)formamide was first synthesized by the reaction of (4-methoxyphenyl)amine with ethyl formate. The structure of trimethylsilyl(4-methoxyphenyl)-carbamate and N-(4-methoxyphenyl)formamide was determined by X-ray diffraction (XRD) analysis.

AIM AND OBJECTIVE Thiazol-2-imine derivatives are interested for their pharmaceutical and biologic activities. A literature survey reveals that there have been no any reports on the synthesis of thiazol-2-imine derivatives without substituents in position C-4 and C-5 via one-pot reaction. Herein we report an efficient one-pot route for synthesis of these compounds in good to high yields. MATERIALS AND METHOD To a stirred mixture of amine (1 mmol) and phenylisothiocyanate (1 mmol) in EtOH (2 ml), KI (0.1 mmol) and DABCO (0.2 mmol) were added under reflux condition. Then α- chloroacetaldehyde (2 mmol) was added drop wise to the reaction mixture. After completion of the reaction, the product was purified over a silica gel short column (EtOAc/n-Hexane, 1:9). RESULTS One pot reaction of primary amine, phenylisocyanate, and α-chloroacetaldehyde was carried out in the presence of various base and KI in different solvents. It was found that the maximum yield was obtained when the temperature reaches to the boiling point of EtOH. Comparing the reaction results in EtOH, CH3CN, THF, CH2Cl2, and H2O at reflux in the presence of various base, demonstrate that the yield of reaction in EtOH in the presence of DABCO was the most effective. When the reaction runs at the 20 mol% of the DABCO and 10 mol% of the KI, the yield and the time of the reaction were excellent. CONCLUSION One-pot procedure can be used for the synthesis of thiazol-2-imine derivatives via the reaction of primary amines, α-chloroacetaldehyde, and phenylisothiocyanate in the presence of a catalytic amount of DABCO and potassium iodide in ethanol.

Two [3+1] fragmentations of the Lewis acid stabilized bicyclo[1.1.0]tetraphosphabutanide Li[Mes*P4⋅ BPh3] (Mes*=2,4,6-tBu3C6H2) are reported. The reactions proceed by extrusion of a P1fragment, induced by either an imidazolium salt or phenylisocyanate, with release of the transient triphosphirene Mes*P3, which was isolated as a dimer and trapped by 1,3-cyclohexadiene as a Diels–Alder adduct. DFT quantum chemical computations were used to delineate the reaction mechanisms. These unprecedented pathways grant access to both P1- and P3-containing organophosphorus compounds in two simple steps from white phosphorus.

The geminal frustrated Lewis pair (FLP) tBu2PCH2BPh2 (1) reacts with phenyl‐, mesityl‐, and tert‐butyl azide affording, respectively, six, five, and four‐membered rings as isolable products. DFT calculations revealed that the formation of all products proceeds via the six‐membered ring structure, which is thermally stable with an N‐phenyl group, but rearranges when sterically more encumbered Mes−N3 and tBu−N3 are used. The reaction of 1 with Me3Si−N3 is believed to follow the same course, yet subsequent N2 elimination occurs to afford a four‐membered heterocycle (5), which can be considered as a formal FLP‐trimethylsilylnitrene adduct. Compound 5 reacts with hydrochloric acid or tetramethylammonium fluoride and showed frustrated Lewis pair reactivity towards phenylisocyanate., One plus one equals 4, 5, or 6: The geminal frustrated Lewis pair tBu2PCH2BPh2 reacts with phenyl‐, mesityl‐, tert‐butyl and trimethylsilyl azide affording, respectively, six, five, and four‐membered rings as isolable products. DFT calculations revealed that the formation of all products proceeds via the six‐membered ring structure, which is the thermodynamic product with an N‐phenyl group, but rearranges when sterically more encumbered substituents are used.

4,4-methelenebis(phenyl isocyanate) (MDI) based polyurethanes have vast variety of applications. Its applications will be broaden with an understanding of the microstructural changes in the polymer matrix due to UV exposure. In this study, the fluorescence analysis has been used to uncover the microstructural changes of polymer matrix in a UV environment. When this polymer is exposed to UV radiation hard segments crystallize and the process is assisted localized melting. When the UV exposure was ceased molecules rearrange back to their initial structure due to the tensile forces originating from soft-segment crystallization. However, tensile forces are not strong enough for a complete recovery of the micro structure. Residual solvent molecules can also disturb the recovery.

This work described a simple and efficient synthesis of dialkyl 3-(alkylamino)-1-aryl-1H-pyrazole-4,5-dicarboxylates via a three component reaction between arylhydrazine, alkylisocyanid and dialkylacetylenedicarboxylates in the presence of phenylisocyanate and α-Fe2O3 nanoparticles. Eco friendly, solvent-free conditions, excellent yields, and short reaction times, inexpensive and readily available catalysts are the main advantages of this method. In this work, phenylisocyanate and α-Fe2O3 nanoparticles used as a potent mixed catalyst for promoting the reaction and taking it in a special way to obtain the titled compounds in good to excellent yields. This reaction was not carried out without any of the components of this mixed catalyst. It means that for performance this reaction both of the mixed catalyst components is required.

Reaction of 6-amino-3-methyl-4-(substituted phenyl)-1,4- dihydropyrano[2,3-c]pyrazole-5-carbonitrile (1) with triethylorthoformate followed by treatment with hydrazine hydrate, formic acid, acetic acid, phenylisocyanate, ammonium thiocyanate and formamide afforded the corresponding pyranopyrimidine derivatives 2-6. Cyclocondensation of 1 with cyclohexanone afforded pyrazolopyranoquinoline 7. One-pot process of diazotation and de-diazochlorination of 1 afforded pyrazolopyranotriazine derivative 8, which upon treatment with secondary amines afforded 9 and 10a- c. Condensation of 2 with aromatic aldehyde gave the corresponding Schiff bases 11a,b, the oxidative cyclization of the hydrazone with appropriate oxidant afforded 11-(4- fluorophenyl))- 2-(4-substituted phenyl)-10-methyl-8,11-dihydropyrazolo-[ 4’,3’:5,6]pyrano[3,2-e][1,2,4]triazolo[1,5-c]pyrimidines (12a,b). Structures of the synthesized compounds were confirmed by spectral data and elemental analysis. All synthesized compounds were evaluated for antibacterial and antifungal activities compared to norfloxacin and fluconazole as standard drugs. Compounds 9, 10c, 12a and 15 were found to be the most potent antibacterial agents, with activity equal to that of norfloxacin. On the other hand, compound 5 exhibited higher antifungal activity compared to fluconazole.

Five-membered metallacycloallene compounds, 1-zirconacyclopenta-2,3-dienes 1, derived from but-1-en-3-ynes 2 and low-valent zirconocene, reacted with esters and isocyanates. Reactions of 1 with carboxylic esters such as ethyl acetate and methyl benzoate resulted in the formation of alkynyl ketones after hydrolysis, albeit in low yields, and diethyl carbonate gave alkynyl esters in moderate yields. Insertion of isocyanates such as phenylisocyanate to the Zr–C bond of 1 afforded an alkynyl amide when 1 had substituents at the 2,4-positions (1a), while the zirconium complexes 1 that had silyl groups at the 2,5-positions, 1b and 1c, gave dienyl amides after hydrolysis. These reactions involved C O insertion into the Zr-Csp3 bond in 1. It is likely that the insertion afforded seven-membered 1-oxa-2-zirconacyclohepta-3,4-diene intermediates first, whilst the reaction of 2,5-disilyl-1-zirconacyclopenta-2,3-dienes 1b-c with isocyanates formed five-membered 1-oxa-2-zirconacyclopent-3-ene intermediates. Additional C–C bond formation reactions of these intermediates via transmetallation to copper salts followed by addition of allyl halides furnished allylated products.

New compounds 5 and 9 using DNA bases e.g. Adenine 1 and Guanine 6 derivatives have been synthesized. The use of simple methods to synthesize compounds 5 and 9 were done using pyrimidine as an alternative DNA base ring. Another design to synthesize new simple pyrimidine rings utilizing thiourea and ethylcyano acetate to afford 6-amino-2-thiouracil was adopted. The reaction of thiouracil 10 with chloro cyano or chloro ester and ketone, resulted in the formation of adduct compounds 18-21 , rather than the formation of compound 17 . All the synthesized compounds were subjected to docking study, in order to gain insights into their binding modes against cyclin-dependent protein kinase 2 (CDK-2) that is involved heavily in cell cycle regulation and receptor protein B-cell lymphoma 2 (BCL-2) which is involved in cell apoptosis. These targets were selected based on their key roles in cancer progression via the regulation of the cell cycle and DNA replication. Molecular-docking analyses showed that compound 14e was the best docked ligand against both targets, as it displayed the lowest binding energy, critical hydrogen bonds and hydrophobic interactions with the targets.

In this study pyrimido[4,5-d]pyrimidine derivatives have been synthesized via a suitable and efficient procedure using one-pot multi-component reactions of phenylisocyanate, N,N-dimethyl-6-amino uracil and aromatic aldehydes in presence of TiO2@ILs as a nanocatalyst. In this method all products were prepared with good to excellent yields using TiO2@ILs. Moreover, TiO2 NPs were prepared using beet juice extract and functionalized with ILs based on imidazole. TiO2@ILs nanocatalyst has been characterized by different spectroscopic techniques such as FT-IR, TGA, XRD, SEM and EDX. Moreover, this ionic liquid presented itself as a good protective and activator agent for nanocatalysts.

Although various click polymerization reactions (thiol-ene, thiol-yne, thiol-Michael, thiol-epoxy and amine-epoxy) have been utilized to prepare either hybrid or organic monolithic columns with homogeneous network structures, there were few reports on fabrication of monolithic CSPs via click polymerization. Herein, a fast and robust approach was explored to fabricate cinchona-based monolithic hybrid CSPs via photo-initiated thiol-ene polymerization within 10 min in one step. A self-synthesized octakis(3-mercaptopropyl) octasilsesquioxane (POSS-SH) was polymerized with phenylisocyanate cinchonidine (PCD) and (+)-N,N'-diallyl-L-tartardiamide (DATDA) or 1,2,4-trivinylcyclohexane (TVCH). The resulting two kinds of as-synthesized monolithic CSPs, poly(POSS-co-DATDA-co-PCD) and poly(POSS-co-TVCH-co-PCD), were evaluated for cLC enantioseparation of acidic racemates. It was found that they exhibited different enantioseparation ability due to using different multivinyl crosslinkers. The influence of ACN content in mobile phase on the enantioseparation of acidic racemates was investigated. The separation mechanism was also discussed on the basis of a comparison of enantioseparation on two kinds of hybrid monolithic CSPs.

Substances like 3-aminopropyltriethoxysilane are often used as adhesive promoters in various formulations for coatings or to adjust the properties of siloxanes and other polymers. Cyclisation of similar substances is also interesting because of the formation of the Si-N bond. 1-Aza-2-silacyclopentanes were synthesised from 3-aminopropylalkoxysilanes by intramolecular condensation reactions and substitution reactions at the silicon atom. The products tend to undergo ring-opening polymerisation. In contrast to literature reports, they can only be isolated as N-substituted derivatives. Phenylisocyanate inserts into the Si-N bonds of cyclic aminosilanes to form seven-membered heterocycles. Furthermore, phenylisocyanate reacts with N-H bonds in the same molecule. Two insertion products were isolated, and their crystal structures were determined.

The semi-rigid polyurethane (PU) film based on functionalized liquid natural rubber (FLNR) from cup lump rubber waste as the soft segment was prepared by one-shot and two-shot method. The hard segment consists with 4,4’-methylenebis-(phenylisocyanate) (MDI) and 1,4 butanediol (BDO). The urethane linkage formation was confirmed by FTIR with a N-H peak at 3317 cm−1 and disappearance NCO peak at 2262 cm−1. A rubber polyol as soft phase contributes a major implication in the polymer products and two-shot reaction was performed as better processable technique. The segmented interactions of polymer from solubility behaviour indicate stronger interaction between hard and soft segment of two-shot method compared to one-shot method preparation. The semi-rigid character of the PU with low polyol chain length and high soft phase domain favoured solubility in non-polar solvent (toluene and chloroform) and low polar solvent (THF). As for high polyol chain, it was insoluble in any solvent thus its high stability.

A novel and original strategy to obtain rapidly a large diversity of C-8 and N-9 substituted purines was developed. The present procedure describes annulation reactions in one or two steps starting from 5-aminoimidazole-4-carbonitriles 1–8 in moderate to good yields. 8,9-Disubstituted-6,9-dihydro-1H-purin-6-ones 9–14, 6-amino-8,9-disubstituted-3,9-dihydro-2H-purin-2-ones 15–20, 8,9-disubstituted-3,9-dihydro-2H-purin-2,6-diamines 21–24 and 6-imino-1-phenyl-8,9-disubstituted-6,9-dihydro-1H-purin-2-(3H)-ones 25–26 were synthesized in one step using formic acid, urea, guanidine carbonate, and phenylisocyanate, respectively, whereas 8,9-disubstituted-9H-purin-6-amines 27–31 and 6-imino-8,9-disubstituted-6,9-dihydro-1H-purin-1-amines 32–33 were obtained in two steps using formamide and hydrazine, respectively.

The presented results make an original contribution to the development of knowledge on the prediction and/or modeling of the abrasive wear properties of polyurethanes. A series of segmented linear polyurethane elastomers (PUR)—In which the hard segments consist of 4,4′-methylene bis(phenylisocyanate) and 1,4-butanodiol, whilst polyether, polycarbonate, or polyester polyols constitute the soft segments—Were synthesized and characterized. The hardness and wear performance as functions of the variable chemical composition of polyurethane elastomers were evaluated in order to define the relationship between studied factors. The microstructure was characterized in detail, including analysis of the hydrogen bonding by Fourier transformed infrared (FT-IR) spectroscopy and the phase structure by X-ray scattering (WAXS) and differential scanning calorimetry (DSC) methods. The presented studies provide the key features of the polymer composition affecting the abrasive resistance as well as attempts to explain the origin of the differences in the polyurethane elastomers’ performance.