46925-32-0

Upstream product

• 1449-46-3 benzyltriphenylphosphonium bromide 
• 1571-08-0 methyl 4-formylbenzoate 
• 2417-72-3 Methyl 4-(bromomethyl)benzoate 
• 100-52-7 benzaldehyde 
• 42497-80-3 methyl 4-(phenylethynyl)benzoate 
• 1100-88-5 benzyltriphenylphosphonium chloride 
• 536-74-3 phenylacetylene 
• 100-39-0 benzyl bromide 
• 186581-53-3 diazomethane 
• 98-87-3 benzylidene dichloride 

Downstream Products

• 72318-10-6 4-[1-Fluoro-2-phenyl-2-(2,2,2-trifluoro-acetoxy)-ethyl]-benzoic acid methyl ester 
• 72301-35-0 erythro-1-fluoro-2-hydroxy-1-<4-(carbomethoxy)phenyl>-2-phenylethane 
• 14518-67-3 methyl 4-(phenylethyl)benzoate 

Relevant academic research and scientific papers

Ligand-free (: Z)-selective transfer semihydrogenation of alkynes catalyzed by in situ generated oxidizable copper nanoparticles

Herein, we present (Z)-selective transfer semihydrogenation of alkynes based on in situ generated CuNPs in the presence of hydrogen donors, such as ammonia-borane and a green protic solvent. This environmentally friendly method is characterized by operational simplicity combined with high stereo- and chemoselectivity and functional group compatibility. Auto-oxidation of CuNPs after the completion of a semihydrogenation reaction results in the formation of a water-soluble ammonia complex, so that the catalyst may be reused several times by simple phase-separation with no need for any special regeneration processes. Formed NH4B(OR)4 can be easily transformed back into ammonia-borane or into boric acid. In addition, a one-pot tandem sequence involving a Suzuki reaction followed by semihydrogenation was presented, which allows minimization of chemical waste production.

Chemoselective Hydrogenation of Alkynes to (Z) -Alkenes Using an Air-Stable Base Metal Catalyst

A highly selective hydrogenation of alkynes using an air-stable and readily available manganese catalyst has been achieved. The reaction proceeds under mild reaction conditions and tolerates various functional groups, resulting in (Z)-alkenes and allylic alcohols in high yields. Mechanistic experiments suggest that the reaction proceeds via a bifunctional activation involving metal-ligand cooperativity.

Chemoselective semihydrogenation of alkynes catalyzed by manganese(i)-PNP pincer complexes

A general manganese catalyzed chemoselective semihydrogenation of alkynes to olefins in the presence of molecular hydrogen is described. The best results are obtained by applying the aliphatic Mn PNP pincer complex Mn-3c which allows the transformation of various substituted internal alkynes to the respective Z-olefins under mild conditions and in high yields. Mechanistic investigations based on experiments and computations indicate the formation of the Z-isomer via an outer-sphere mechanism.

cis-Selective Transfer Semihydrogenation of Alkynes by Merging Visible-Light Catalysis with Cobalt Catalysis

Herein, the first example of visible-light-driven, cobalt-catalyzed transfer semihydrogenation of alkynes to alkenes is reported. It is carried out by using Ir[dF(CF3)ppy]2(dtbbpy)]PF6 as photosensitizer, CoBr2/n-Bu3P as proton-reducing catalyst, and i-Pr2NEt/AcOH as the hydrogen source. Under the established catalytic system, the semihydrogenation proceeds with Z as the major selectivity and with inhibition of over-reduction. Under mild reaction conditions, both internal and terminal alkynes, as well as reducible functional groups such as halogen, cyano, and ester, are tolerated. Preliminary mechanistic studies revealed the dual role of the photosensitizer in initiating the reaction via a single-electron transfer process and controlling the stereoselectivity via an energy transfer process. (Figure presented.).

Method for catalytically reducing alkynes into olefins through visible light induction

The invention discloses a method for catalytically reducing alkynes into olefins through visible light induction. The method can avoid generation of over-reduced alkane products and the highest yieldis 99%. The method comprises the following steps: by taking an alkyne as a raw material, adding a photosensitizer and a cobalt catalyst, then adding a phosphine ligand or bipyridine ligand, an electronic sacrificial reagent, acetic acid and an organic solvent under inert gas protection, and irradiating with blue light at room temperature for 7-14 hours; and after the reaction is finished, spin-drying an obtained reaction solution, and carrying out silica gel column chromatography separation to obtain an olefin product; wherein the organic solvent is 1, 4-dioxane or tetrahydrofuran, and the alkyne is an aliphatic alkyne or an aromatic alkyne. Reduction of alkyne is realized through a hydrogen transfer strategy, use of dangerous hydrogen is avoided, generation of overreduction products is avoided, reaction conditions are mild, the reaction yield is high, and the method has a good application prospect.

Stereoselective Chromium-Catalyzed Semi-Hydrogenation of Alkynes

Chromium complexes have found very little applications as hydrogenation catalysts. Here, we report a Cr-catalyzed semi-hydrogenation of internal alkynes to the corresponding Z-alkenes with good stereocontrol (up to 99/1 for dialkyl alkynes). The catalyst comprises the commercial reagents chromium(III) acetylacetonate, Cr(acac)3, and diisobutylaluminium hydride, DIBAL?H, in THF. The semi-hydrogenation operates at mild conditions (1-5 bar H2, 30 °C).

An Annelated Mesoionic Carbene (MIC) Based Ru(II) Catalyst for Chemo- And Stereoselective Semihydrogenation of Internal and Terminal Alkynes

The catalytic utility of [RuL1(CO)2I2] (1), containing an annelated π-conjugated imidazo-naphthyridine-based mesoionic carbene (MIC) ligand (L1), is evaluated for E-selective alkyne semihydrogenation. The precatalyst 1, in combination with 2 equiv of AgBArF, semihydrogenates a broad range of internal alkynes with molecular hydrogen (5 bar) in water. (E)-Alkenes are accessed in high yields, and a number of reducible functional groups are tolerated. A chelate MIC ligand and two cis carbonyls provide a well-defined platform at the Ru center for hydrogenation and isomerization. The loss of two iodides and the presence of two carbonyls render the Ru center electron deficient and thus the formation of metal vinylidenes with terminal alkynes is avoided. This is leveraged for the semihydrogenation of terminal alkynes by the same catalytic system in isopropyl alcohol. Reaction profile, isomerization, kinetic, and DFT studies reveal initial alkyne hydrogenation to a (Z)-alkene, which further isomerizes to an (E)-alkene via metal-catalyzed Z → E isomerization.

A alkyne high selectivity also restored to Z - type of olefins

The invention discloses a alkyne high selectivity also restored to Z - type olefin method: the cuprous chloride, ligand-butyl potassium is added in the Schlenk reaction tube, vacuum, in an inert gas conditions, adding organic solvent A, stir at room tempe

Cobalt catalyzed stereodivergent semi-hydrogenation of alkynes using H2O as the hydrogen source

Cobalt-catalyzed stereodivergent semi-hydrogenation of internal alkynes to alkenes is developed. The reaction proceeded through transfer hydrogenation under mild conditions using a base metal CoI2 as the catalyst, and H2O/MeOH as the hydrogen source with Zn as the reductant. The E/Z-selectivity of the product could be switched by changing the solvent and by inclusion/exclusion of a bidentate phosphine ligand (dppe). This method provides a simple and cost effective pathway for the synthesis of 1,2-dideuterioalkenes.

Stereoselective Alkyne Hydrogenation by using a Simple Iron Catalyst

The stereoselective hydrogenation of alkynes constitutes one of the key approaches for the construction of stereodefined alkenes. The majority of conventional methods utilize noble and toxic metal catalysts. This study concerns a simple catalyst comprised of the commercial chemicals iron(II) acetylacetonate and diisobutylaluminum hydride, which enables the Z-selective semihydrogenation of alkynes under near ambient conditions (1–3 bar H2, 30 °C, 5 mol % [Fe]). Neither an elaborate catalyst preparation nor addition of ligands is required. Mechanistic studies (kinetic poisoning, X-ray absorption spectroscopy, TEM) strongly indicate the operation of small iron clusters and particle catalysts.