Reexamination of an Energetic Nitrate Ester SHN

A well-known energetic nitrate ester sorbitol hexanitrate (SHN) was synthesized and characterized. SHN was shown to exhibit the highest density at ambient temperature among all known nitrate esters synthesized from simple polyols. SHN was compared with conventional 1,4-dinitrato-2,3-dinitro-2,3-bis(nitratomethylene)-butane (SMX) as a component of plasticizers in compositions comprising polar synthetic polymers (polyurethane and butadiene/acrylonitrile copolymer). Solid–liquid diagrams for SHN and SMX in diethylene glycol dinitrate (DEGDN) are presented. The energy characteristics and densities of the two-component plasticizers were shown to be higher than those of DEGDN alone. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Stannylation of Aryl Halides, Stille Cross-Coupling, and One-Pot, Two-Step Stannylation/Stille Cross-Coupling Reactions under Solvent-Free Conditions

Solvent-free protocols for palladium-catalyzed stannylation of aryl halides, Stille cross-coupling, and one-pot, two-step stannylation/Stille cross-coupling (SSC) are reported for the first time. (Het)aryl halides bearing acceptor, donor, as well as sterically demanding substituents are stannylated and/or coupled in high yields. The reactions are catalyzed by conventional palladium(II) acetate/PCy3 [Pd(OAc)2/PCy3] under air, using available base CsF, and without the use of high purity reagents. The developed synthetic procedures are versatile, robust, and easily scalable. The absence of solvent, and the elimination of isolation procedures of aryl stannanes makes the SSC protocol simple, step economical, and highly efficient for the synthesis of biaryls in a one-pot two-step procedure. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Reexamination of an Energetic Nitrate Ester SHN

A well-known energetic nitrate ester sorbitol hexanitrate (SHN) was synthesized and characterized. SHN was shown to exhibit the highest density at ambient temperature among all known nitrate esters synthesized from simple polyols. SHN was compared with conventional 1,4-dinitrato-2,3-dinitro-2,3-bis(nitratomethylene)-butane (SMX) as a component of plasticizers in compositions comprising polar synthetic polymers (polyurethane and butadiene/acrylonitrile copolymer). Solid–liquid diagrams for SHN and SMX in diethylene glycol dinitrate (DEGDN) are presented. The energy characteristics and densities of the two-component plasticizers were shown to be higher than those of DEGDN alone. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Stannylation of Aryl Halides, Stille Cross-Coupling, and One-Pot, Two-Step Stannylation/Stille Cross-Coupling Reactions under Solvent-Free Conditions

Solvent-free protocols for palladium-catalyzed stannylation of aryl halides, Stille cross-coupling, and one-pot, two-step stannylation/Stille cross-coupling (SSC) are reported for the first time. (Het)aryl halides bearing acceptor, donor, as well as sterically demanding substituents are stannylated and/or coupled in high yields. The reactions are catalyzed by conventional palladium(II) acetate/PCy3 [Pd(OAc)2/PCy3] under air, using available base CsF, and without the use of high purity reagents. The developed synthetic procedures are versatile, robust, and easily scalable. The absence of solvent, and the elimination of isolation procedures of aryl stannanes makes the SSC protocol simple, step economical, and highly efficient for the synthesis of biaryls in a one-pot two-step procedure. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Hydrohydrazination of Arylalkynes Catalyzed by an Expanded Ring N-Heterocyclic Carbene (er-NHC) Gold Complex under Solvent-Free Conditions

[(THD-Dipp)AuOTf], supported by the strongly electron donating, sterically bulky THD-Dipp (1,3-bis(2,6-diisopropylphenyl)hexahydro-2H-1,3-diazepine-2-ylidene) seven-membered N-heterocyclic carbene ligand, efficiently promotes intermolecular addition of Ts- and Boc-hydrazine to arylalkynes under solvent-free conditions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

One-Pot Synthesis of 5-Amino-1,2,3-triazole Derivatives via Dipolar Azide−Nitrile Cycloaddition and Dimroth Rearrangement under Solvent-Free Conditions

An efficient one-pot methodology for the preparation of 5-amino-1,2,3-triazole derivatives based on the combination of dipolar azide−nitrile cycloaddition with Dimroth rearrangement under solvent-free conditions has been developed. © 2021 Wiley-VCH Gmb

Addition homo- and copolymerization of 3-triethoxysilyltricyclo[4.2.1.02,5]non-7-ene

New norbornene type monomer bearing reactive triethoxysilyl group was synthesized, and its addition homo- and copolymerization with 3-trimethylsilyltricyclonon-7-ene was studied. The target monomer was obtained using regio- and stereospecific [2σ+2σ+2π] cyclo-addition of quadricyclane with vinyltrichlorosilane followed by the reaction of the formed cycloadduct with ethanol in the presence of triethylamine. Addition polymerization was investigated over the three-component Pd-containing catalytic system (Pd complex, Na+[B(3,5-(CF3)2C6H3)4]–(cocatalyst) and tricyclohexylphosphine). The N-heterocyclic carbene Pd complex (SIPrPd(cinn)Cl) with high activity and tolerance to the Si—O—C moieties was used as a catalyst. The yields of the homo- and copolymers were 24—68% depending on the monomer (comonomer): Pd: B: PCy3 ratio. The obtained addition polymers are high-molecular-weight amorphous products, the glass transition temperature of which exceeds 300 °C. The presence of reactive Si(OC2H5)3 groups in the homo- and copolymers made it possible to carry out a hard-to-realize cross-linking involving side substituents and followed by the formation of insoluble polymers. © 2018, Springer Science+Business Media, LLC, part of Springer Nature

Hydrohydrazination of Arylalkynes Catalyzed by an Expanded Ring N-Heterocyclic Carbene (er-NHC) Gold Complex under Solvent-Free Conditions

[(THD-Dipp)AuOTf], supported by the strongly electron donating, sterically bulky THD-Dipp (1,3-bis(2,6-diisopropylphenyl)hexahydro-2H-1,3-diazepine-2-ylidene) seven-membered N-heterocyclic carbene ligand, efficiently promotes intermolecular addition of Ts- and Boc-hydrazine to arylalkynes under solvent-free conditions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Eight-membered-ring diaminocarbenes bearing naphthalene moiety in the backbone: DFT studies, synthesis of amidinium salts, generation of free carbene, metal complexes, and solvent-free copper catalyzed azide-alkyne cycloaddition (CuAAC) reaction

A new type of eight-membered ring N-heterocyclic carbene (NHC) bearing a rigid naphthalene moiety in the backbone is reported for the first time. Stereoelectronic properties of 4,5-dihydro-1H-naphtho[1,8-ef][1,3]diazocin-3(2H)-ylidene (NaphtDHD) and smaller ring NHCs were theoretically studied at the DFT level. Amidinium salts were prepared from corresponding amidines and dibromides. Free carbene NaphtDHD-Dipp (Dipp = 2,6-diisopropylphenyl) was generated in solution by treatment of the corresponding salt with LiHMDS. It is stable in solution at low temperatures, while decomposing rapidly at room temperature. Silver(i) and copper(i) complexes were synthesized and structurally characterized in the solid state. The copper(i) complex [(NaphtDHD-Mes)CuBr] (Mes = mesityl, 2,4,6-trimethylphenyl) exhibits high catalytic activity in alkyne-azide cycloaddition (CuAAC) reaction under solvent-free conditions. © The Royal Society of Chemistry