56544-13-9

Upstream product

• 1236132-32-3 Te-propanoylmethyl benzenecarbotelluroate 
• 10364-94-0 1-benzoylimidazole 
• 65001-62-9 3-buten-2-yl benzoate 
• 65-85-0 benzoic acid 
• 503-17-3 dimethylacetylene 

Downstream Products

• 3306-36-3 (1R)-1-methylpropyl benzoate 
• 4909-81-3 (1S)-methylpropyl benzoate 
• 4909-81-3 s-butyl benzoate 

Relevant academic research and scientific papers

Gold(i)-catalyzed addition of carboxylic acids to internal alkynes in aqueous medium

We report herein the efficient hydro-oxycarbonylation of symmetrical and unsymmetrical internal alkynes with carboxylic acids in water at 60 °C, employing the catalytic system [AuCl(PPh3)]/AgOAc (5 mol%). This simple and eco-friendly protocol allows for the synthesis of a wide variety of trisubstituted enol esters (37 examples) in high yields and with complete Z-stereoselectivity. The use of microwave irradiation as an alternative energy source has also been evaluated.

Broad Scope Synthesis of Ester Precursors of Nonfunctionalized Chiral Alcohols Based on the Asymmetric Hydrogenation of α,β-Dialkyl-, α,β-Diaryl-, and α-Alkyl-β-aryl-vinyl Esters

The catalytic asymmetric hydrogenation of trisubstituted enol esters using Rh catalysts bearing chiral phosphine-phosphite ligands (P-OP) has been studied. Substrates covered comprise α,β-dialkyl, α-alkyl-β-aryl, and α,β-diarylvinyl esters, the corresponding hydrogenation products being suitable precursors to prepare synthetically relevant chiral nonfunctionalized alcohols. A comparison of reactivity indicates that it decreases in the order: α,β-dialkyl > α-alkyl-β-aryl > α,β-diaryl. Based on the highly modular structure of P-OP ligands employed, catalyst screening identified highly enantioselective catalysts for α,β-dialkyl (95-99% ee) and nearly all of α-alkyl-β-aryl substrates (92-98% ee), with the exception of α-cyclohexyl-β-phenylvinyl acetate which exhibited a low enantioselectivity (47% ee). Finally, α,β-diarylvinyl substrates showed somewhat lower enantioselectivities (79-92% ee). In addition, some of the catalysts provided a high enantioselectivity in the hydrogenation of E/Z mixtures (ca. Z/E = 75:25) of α,β-dialkylvinyl substrates, while a dramatic decrease on enantioselectivity was observed in the case of α-methyl-β-anisylvinyl acetate (Z/E = 58:42). Complementary deuteration reactions are in accord with a highly enantioselective hydrogenation for both olefin isomers in the case of α,β-dialkylvinyl esters. In contrast, deuteration shows a complex behavior for α-methyl-β-anisylvinyl acetate derived from the participation of the E isomer in the reaction.

Method for the preparation of palladium(I) tri-tert-butylphosphine bromide dimer and process for its use in isomerization reactions

The invention provides a new method for the preparation of the dimeric Pd(l) tri-tert.-butylphosphine bromide complex, characterized by the chemical formula [Pd(μ-Br)(PtBu3)]2. The method is based on a comproportionation r

Method for the Preparation of Palladium(I) Tri-Tert-Butylphosphine Bromide Dimer and Process for its Use in Isomerization Reactions

The invention provides a new method for the preparation of the dimeric Pd(l) tri-tert.-butylphosphine bromide complex, characterized by the chemical formula [Pd(μ-Br)(PtBu3)]2. The method is based on a comproportionation reaction in which a Pd(ll) compound (=PdBr2) is reacted with a Pd(0) compound (=Pd(PtBu3)2) in organic solvents to yield the [Pd(μ-Br)(PtBu3)]2 compound having the Pd atoms in the formal oxidation state +1. Unreacted PdBr2 may be reused in the process. The method is straightforward and applicable for industrial scale production and provides high product yields. Further, a new process for the isomerization of allyl ethers of the general type R1—C(O)—O—CH(R2)—C(R3)═CH2 employing the compound Pdμ-Br)(PtBu3)]2 as a catalyst is disclosed.

[Pd(μ-Br)(PtBu3)]2 as a highly active isomerization catalyst: Synthesis of enol esters from allylic esters

The dimeric Pd(I)-complex [Pd(μ-Br)(PtBu3)] 2 was found to be highly active for catalyzing double-bond migration in various substrates such as unsaturated ethers, alcohols, amides, and arenes, under mild conditions. It efficiently mediates the conversion of allylic esters into enol esters, rather than inserting into the allylic C-O bond. The broad applicability of this reaction was demonstrated with the synthesis of 22 functionalized enol esters.

Te-1-acylmethyl and Te-1-iminoalkyl telluroesters: Synthesis and thermolysis leading to 1,3-diketones and O-alkenyl and O-imino esters

A series of Te-1-acylmethyl carbotelluroates was prepared in good isolated yields from the reaction of potassium carbotelluroates with -haloketones in acetonitrile. Thermolysis of the telluroesters afforded vinyl esters in 20-50% yields, while treatment of the carbotellurorates with potassium t-butanolate led to 1,3-diketones in 30-75% yields with the liberation of black tellurium. The reaction of potassium carbotelluroates with -haloaceto oximes gave O-acyl oximes in 50-70% yields via Te-1-iminomethylcarbotelluroates. Copyright Taylor & Francis Group.