20389-19-9

Upstream product

• 103-30-0 (E)-1,2-diphenyl-ethene 
• 4216-89-1 bicyclo<2.2.2>octane-2,3-dione 
• 33712-34-4 benzyl-d2 chloride 
• 66223-95-8 1,3-diphenyl-2-propanone-1,1,3,3-d4 
• 501-65-5 diphenyl acetylene 
• 103-29-7 1,1'-(1,2-ethanediyl)bisbenzene 
• 645-49-8 cis-stilben 
• 21175-64-4 1,1-dideuteriophenylmethanol 

Relevant academic research and scientific papers

Transition-Metal-Free, Selective Reductive Deuteration of Terminal Alkynes with Sodium Dispersions and EtOD- d1

A transition-metal-free single electron transfer reaction has been developed for the synthesis of [D3]-alkenes from terminal alkynes using sodium dispersions as the electron donor and EtOD-d1 as the deuterium source. Both reagents ar

HIGHLY SELECTIVE ELECTROCHEMICAL HYDROGENATION OF ALKYNES

Disclosed are electrochemical methods to prepare an alkane or an alkene, such as a cis- alkene, from an alkyne, or an alkane from an alkene. The method utilizes an electrochemical cell having a cathode and an anode and a reactor.

Rare-Earth Supported Nickel Catalysts for Alkyne Semihydrogenation: Chemo- And Regioselectivity Impacted by the Lewis Acidity and Size of the Support

Bimetallic catalysts of nickel(0) with a trivalent rare-earth ion or Ga(III), NiML3 (where L is [iPr2PCH2NPh]-, and M is Sc, Y, La, Lu, or Ga), were investigated for the selective hydrogenation of diphenylacetylene (DPA) to (E)-stilbene. Each bimetallic complex features a relatively short Ni-M bond length, ranging from 2.3395(8) ? (Ni-Ga) to 2.5732(4) ? (Ni-La). The anodic peak potentials of the NiML3 complexes vary from -0.48 V to -1.23 V, where the potentials are negatively correlated with the Lewis acidity of the M(III) ion. Three catalysts, Ni-Y, Ni-Lu, and Ni-Ga, showed nearly quantitative conversions in the semihydrogenation of DPA, with NiYL3 giving the highest selectivity for (E)-stilbene. Initial rate studies were performed on the two tandem catalytic reactions: DPA hydrogenation and (Z)-stilbene isomerization. The catalytic activity in DPA hydrogenation follows the order Ni-Ga > Ni-La > Ni-Y > Ni-Lu > Ni-Sc. The ranking of catalysts by (Z)-stilbene isomerization initial rates is Ni-Ga ? Ni-Sc > Ni-Lu > Ni-Y > Ni-La. In operando 31P and 1H NMR studies revealed that in the presence of DPA, the Ni bimetallic complexes supported by Y, Lu, and La form the Ni(η2-alkyne) intermediate, (η2-PhCCPh)Ni(iPr2PCH2NPh)2M(κ2-iPr2PCH2NPh). In contrast, the Ni-Ga resting state is the Ni(η2-H2) species, and Ni-Sc showed no detectable binding of either substrate. Hence, the mechanism of Ni-catalyzed diphenylacetylene semihydrogenation adheres to two different kinetics: an autotandem pathway (Ni-Ga, Ni-Sc) versus temporally separated tandem reactions (Ni-Y, Ni-Lu, Ni-La). Collectively, the experimental results demonstrate that modulating a base-metal center via a covalently appended Lewis acidic support is viable for promoting selective alkyne semihydrogenation.

New photocatalytic fixed-point deuteration method for carbon-carbon unsaturated bonds

The invention relates to a new photocatalytic fixed-point deuteration method for carbon-carbon unsaturated bonds. The method is characterized in that an olefin or alkyne compound and a deuterium source undergoes a deuteration reaction under the catalysis of a light source and a photocatalyst to obtain a deuterated product, wherein the deuterium source is deuterated water, deuterated alcohol or deuterated acid, and the reaction temperature is between room temperature and 80 DEG C. The fixed-point deuteration reaction of the olefin or alkyne compound is realized under the photocatalysis action of the photocatalyst with environmentally-friendly and cheap deuterated water or a deuteration reagent as a deuterium source to substitute deuterium gas. Compared with traditional deuteration reactions, the method has a higher selectivity, milder reaction conditions and higher economical suitability, and is suitable for large-scale deuterated chemical substance production.

Reduction deuteration method of unsaturated organic compound containing carbon-carbon triple bond and/or carbon-nitrogen triple bond (by machine translation)

A single electron transfer reaction of an alkali metal medium is applied to reduction of a carbon-carbon triple bond or a carbon-nitrogen triple bond, and an alkyne and a nitrile compound can be respectively converted into deuterated olefin (or alkane) an

Transfer Hydrogenation of Alkenes Using Ethanol Catalyzed by a NCP Pincer Iridium Complex: Scope and Mechanism

The first general catalytic approach to effecting transfer hydrogenation (TH) of unactivated alkenes using ethanol as the hydrogen source is described. A new NCP-type pincer iridium complex (BQ-NCOP)IrHCl containing a rigid benzoquinoline backbone has been developed for efficient, mild TH of unactivated C-C multiple bonds with ethanol, forming ethyl acetate as the sole byproduct. A wide variety of alkenes, including multisubstituted alkyl alkenes, aryl alkenes, and heteroatom-substituted alkenes, as well as O- or N-containing heteroarenes and internal alkynes, are suitable substrates. Importantly, the (BQ-NCOP)Ir/EtOH system exhibits high chemoselectivity for alkene hydrogenation in the presence of reactive functional groups, such as ketones and carboxylic acids. Furthermore, the reaction with C2D5OD provides a convenient route to deuterium-labeled compounds. Detailed kinetic and mechanistic studies have revealed that monosubstituted alkenes (e.g., 1-octene, styrene) and multisubstituted alkenes (e.g., cyclooctene (COE)) exhibit fundamental mechanistic difference. The OH group of ethanol displays a normal kinetic isotope effect (KIE) in the reaction of styrene, but a substantial inverse KIE in the case of COE. The catalysis of styrene or 1-octene with relatively strong binding affinity to the Ir(I) center has (BQ-NCOP)IrI(alkene) adduct as an off-cycle catalyst resting state, and the rate law shows a positive order in EtOH, inverse first-order in styrene, and first-order in the catalyst. In contrast, the catalysis of COE has an off-cycle catalyst resting state of (BQ-NCOP)IrIII(H)[O(Et)···HO(Et)···HOEt] that features a six-membered iridacycle consisting of two hydrogen-bonds between one EtO ligand and two EtOH molecules, one of which is coordinated to the Ir(III) center. The rate law shows a negative order in EtOH, zeroth-order in COE, and first-order in the catalyst. The observed inverse KIE corresponds to an inverse equilibrium isotope effect for the pre-equilibrium formation of (BQ-NCOP)IrIII(H)(OEt) from the catalyst resting state via ethanol dissociation. Regardless of the substrate, ethanol dehydrogenation is the slow segment of the catalytic cycle, while alkene hydrogenation occurs readily following the rate-determining step, that is, β-hydride elimination of (BQ-NCOP)Ir(H)(OEt) to form (BQ-NCOP)Ir(H)2 and acetaldehyde. The latter is effectively converted to innocent ethyl acetate under the catalytic conditions, thus avoiding the catalyst poisoning via iridium-mediated decarbonylation of acetaldehyde.

Stereodivergent Alkyne Reduction by using Water as the Hydrogen Source

A homogeneous Pd-catalyzed stereodivergent reduction of alkynes to Z and E alkenes by using H2O as the H2 source is presented. Mediated by a diboron reagent, the transfer hydrogenation has been accomplished to yield the desired geometrical isomer by rational ligand selection. The switchable stereoselectivity achieved using simple phosphine ligands is generally excellent. D2O has also been used as a D2 source for synthesizing the corresponding deuterated olefins. Supported by a gram-scale synthesis, the reaction can easily be scaled up making it an efficient way to prepare alkenes commercially as well. Mechanistic studies suggest formation of H?PdL2?OAc as the crucial step leading to the presence of two pathways involving H?Pd?B(OR)2 and molecular H2 as active intermediates.

A selective and cost-effective method for the reductive deuteration of activated alkenes

A new single electron transfer reaction for the reductive deuteration of activated alkenes has been developed for the selective synthesis of α,β-dideuterio compounds. A cheap, stable and commercially-available sodium dispersion with high specific surface

Cobalt-catalyzed (Z)-selective semihydrogenation of alkynes with molecular hydrogen

Cobalt-catalyzed highly (Z)-selective semihydrogenation of alkynes using molecular H2 was developed using commercially available and cheap cobalt precursors. A variety of (Z)-alkenes were obtained in moderate to excellent selectivities [(Z)-alkene/(E)-alkene/alkane ratio up to >99 : 1 : 1] and it was found that the readily available ethylenediamine ligand is crucial in determining the selectivity.

Tetrahydroxydiboron-Mediated Palladium-Catalyzed Transfer Hydrogenation and Deuteriation of Alkenes and Alkynes Using Water as the Stoichiometric H or D Atom Donor

There are few examples of catalytic transfer hydrogenations of simple alkenes and alkynes that use water as a stoichiometric H or D atom donor. We have found that diboron reagents efficiently mediate the transfer of H or D atoms from water directly onto unsaturated C-C bonds using a palladium catalyst. This reaction is conducted on a broad variety of alkenes and alkynes at ambient temperature, and boric acid is the sole byproduct. Mechanistic experiments suggest that this reaction is made possible by a hydrogen atom transfer from water that generates a Pd-hydride intermediate. Importantly, complete deuterium incorporation from stoichiometric D2O has also been achieved.