STUDY OF THE INFLUENCE OF DISPERSITY AND CHEMICAL COMPOSITION OF NICKEL RENEUAL ALLOYS ON THE SPECIFICITY OF REDUCTION OF ADAMANTANE-CONTAINING UNSATURED NITRILE

The regularities of the reduction of adamantane-containing unsaturated nitrile-nickel-aluminum alloy are investigated. It has been shown that under the conditions of synthesis it is possible to carry out the simultaneous reduction of both the double bond and the nitrile group. It was found that the reduction of nitriles containing 1 hydroxyl group in the position leads to a significant decrease in the rate of the process. The effect of the grain size composition of the alloy and damping additives on the reduction of unsaturated nitriles has been studied.

Dearomative Allylation of Aromatic Cyanohydrins by Palladium Catalysis: Catalyst-Enhanced Site-Selectivity

A dearomative allylation of aromatic cyanohydrins with allyl borates and allyl stannanes under palladium catalysis was developed. At the initial stage of this study, the dearomative reaction (C4-substitution of the aromatics) was competing with benzyl substitution. To circumvent this issue, the use of palladium and <i>meta</i>-disubstituted triarylphosphine as the catalyst in a 1:1 ratio was found to enhance the site-selectivity, furnishing the desired dearomatized products. As the products possess an unsaturated nitrile moiety, further derivatizations of products such as conjugate additions and reductions were achieved.

Dearomative Allylation of Aromatic Cyanohydrins by Palladium Catalysis: Catalyst-Enhanced Site-Selectivity

A dearomative allylation of aromatic cyanohydrins with allyl borates and allyl stannanes under palladium catalysis was developed. At the initial stage of this study, the dearomative reaction (C4-substitution of the aromatics) was competing with benzyl substitution. To circumvent this issue, the use of palladium and <i>meta</i>-disubstituted triarylphosphine as the catalyst in a 1:1 ratio was found to enhance the site-selectivity, furnishing the desired dearomatized products. As the products possess an unsaturated nitrile moiety, further derivatizations of products such as conjugate additions and reductions were achieved.

Regeneration of Raney®-Nickel Catalyst for the Synthesis of High-Value Amino-Ester Renewable Monomers

Aiming to synthesize high-value renewable monomers for the preparation of renewable specialty polyamides, we designed a new protocol. Amino-esters, produced via the hydrogenation of unsaturated nitrile-esters, are alternative monomers for the production of these polymers. A high monomer yield can be obtained using a Raney®-nickel catalyst despite the drawback of fast deactivation. The hydrogenation of 10-cyano-9-decenoate (UNE11) was tentatively reactivated by three different regeneration procedures: solvent wash, regeneration under hydrogen, and regeneration under sonication. Among these procedures, the in-pot catalyst regeneration (H2 30 bar, 150 °C) demonstrated complete activity recovery and full recycling.

Synthesis of coumarin derivative using polymer supported reagents

Recently, there has been a surge in use of polymer-supported reagents and catalysts become common tools for organic synthesis in what is known as polymer-assisted synthesis since they can simplify product isolation and purification. In this context, coumarin derivative 3 was prepared in good yield and high purity, starting from 3-methoxy salicylaldehyde, using reagents supported on a macroporous ion exchange resin. For this purpose, iminocoumarin and unsaturated nitrile were used as starting materials. The synthesized compounds were characterized by IR, NMR and mass spectrometry.

The Carreira Synthesis of (±)-Gelsemoxonine

The traditional Chinese pharmacopeia includes Gelsemium elegans benth, from which the alkaloid gelsemoxonine 3 was isolated. Erick M. Carreira of the Eidgenössische Technische Hochschule Zürich envisioned (J. Am. Chem. Soc. 2013, 135, 8500) that the unusual azetidine ring of 3 could be established by Brandi contraction of 1 to give 2. Following Brandi and Salaün (Eur. J. Org. Chem. 1999, 2725), the hemiketal 4 was carried onto the aldehyde 9. Condensation with nitromethane followed by dehydration gave the unsaturated nitrile oxide, which cyclized to 10. Epoxidation of 10 across the more open face gave an intermediate epoxide. Addition of 11 to the epoxide, promoted by InBr3, delivered 12 with good stereocontrol. CeCl3-mediated addition of 1-propynyl lithium completed the assembly of 1. A cyclopropanone could be seen as the addition product of carbon monoxide to an alkene. On exposure of 1 to acid, this formal addition was reversed, leading to the β-lactam 2. A computational study of this cleavage was recently reported (Eur. J. Org. Chem. 2011, 5608). Conceptually, one can imagine protonation activating the C–N bond for cleavage, leading to an intermediate such as 14, which then fragments to the acylium ion, leading to cyclization. It is unlikely that 14 would have any real lifetime. On warming with the Petasis reagent, the Boc-protected β-lactam was converted to the alkene 15. Hydroboration proceeded to give the alcohol 16 as a single diastereomer. Reduction followed by oxidation to 17 then set the stage for intramolecular aldol condensation to give 18. The last challenge was the diastereoselective assembly of the N-methoxyoxindole. To this end, oxidation and dehydration of 18 led to the bromo amide 20. As hoped, Heck reductive cyclization proceeded across the more open face of the alkene, leading to 21. Hydroxyl-directed hydrosilylation of the pendant alkyne to give the ethyl ketone then completed the synthesis of gelsemoxonine 3. Twice in this synthesis, advantage was taken of the preparation and reactivity of heteroatom-substituted alkenes. Dimethyl dioxirane, generated as a solution in acetone, was sufficiently water free that the epoxide derived from 10 could survive long enough to react in a bimolecular sense with the ketene silyl acetal 11.

An Ultrasound Mediated Green Synthesis of Benzimidazolylthiounsaturatednitriles Using Water as a Green Solvent

Reaction of 2-cyanothiomethylbenzimidazole 1 with an aromatic aldehydes in water under ultrasonic irradiation for 10–13 min gave the corresponding unsaturated nitriles 2a–h which is an efficient and simple method under green conditions. The unsaturated nitrile derivatives were obtained in 86–98% yield with a short reaction time without any tedious workup procedures.

The effect of the supramolecular network of (Z)-3-(4-(diphenylamino)phenyl)-2-(pyridin-2-yl)-acrylonitrile on the fluorescence behavior of a single crystal: experimental and theoretical studies

The molecular structure, molecular interactions, self-assembly behaviour and optical properties of a α,β-unsaturated nitrile were analyzed.