1242409-36-4

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• 123-11-5 4-methoxy-benzaldehyde 
• 60512-57-4 1-(2,2-dibromovinyl)-4-methoxybenzene 
• 51718-85-5 ethyl 3-(4-methoxyphenyl)propynoate 
• 7706-82-3 (Z)-3-(4-methoxyphenyl)-2-butenoic acid ethyl ester 
• 623-73-4 diazoacetic acid ethyl ester 
• 1515-95-3 p-ethylanisole 
• 64-17-5 ethanol 
• 103987-50-4 3-(4-methoxyphenyl)-2-buten-1-al 
• 108454-55-3 3-(4-methoxyphenyl)-2-butenoic acid ethyl ester 
• 61292-83-9 (+/-)-ethyl 3-(4-methoxyphenyl)butanoate 
• 18310-76-4 3-(4'-methoxyphenyl)butanoyl chloride 
• 6555-30-2 3-(4-methoxyphenyl)butyric acid 
• 104-92-7 1-bromo-4-methoxy-benzene 
• 7706-82-3 (E)-ethyl 3-(4-methoxyphenyl)but-2-enoate 

Relevant academic research and scientific papers

Iridium-Catalyzed Asymmetric Hydrogenation with Simple Cyclohexane-Based P/S Ligands: In Situ HP-NMR and DFT Calculations for the Characterization of Reaction Intermediates

We report a reduced but structurally valuable phosphite/phosphinite-thioether ligand library for the Ir-hydrogenation of 40 minimally functionalized alkenes, including relevant examples with poorly coordinative groups. We found that enantiomeric excesses are mainly dependent on the substrate structure and on some ligand parameters (i.e., the type of thioether/phosphorus moieties and the configuration of the phosphite group), whereas the substituents of the biaryl phosphite moiety had little impact. By tuning the ligand parameters we were able to find highly selective catalysts for a range of substrates (ees up to 99%). These phosphite/phosphinite-thioether ligands have a simple backbone and thus yield simple NMR spectra that reduce signal overlap and facilitate the identification of relevant intermediates. Therefore, by combining HP-NMR spectroscopy and theoretical studies, we were also able to identify the catalytically competent Ir-dihydride alkene species, which made it possible to explain the enantioselectivity obtained.

NeoPHOX - An easily accessible P,N-ligand for iridium-catalyzed asymmetric hydrogenation: Preparation, scope and application in the synthesis of demethyl methoxycalamenene

Using a new class of chiral iridium hydrogenation catalysts, the antitumor natural product demethyl calamenene was synthesized in four steps in >20% overall yield and high enantiomeric purity.

Indene Derived Phosphorus-Thioether Ligands for the Ir-Catalyzed Asymmetric Hydrogenation of Olefins with Diverse Substitution Patterns and Different Functional Groups

A family of phosphite/phosphinite-thioether ligands have been tested in the Ir-catalyzed asymmetric hydrogenation of a range of olefins (50 substrates in total). The presented ligands are synthesized in three steps from cheap indene and they are air-stable solids. Their modular architecture has been crucial to maximize the catalytic performance for each type of substrate. Improving most Ir-catalysts reported so far, this ligand family presents a broader substrate scope, covering different substitution patterns with different functional groups, ranging from unfunctionalized olefins, through olefins with poorly coordinative groups, to olefins with coordinative functional groups. α,β-Unsaturated acyclic and cyclic esters, ketones and amides werehydrogenated in enantioselectivities ranging from 83 to 99% ee. Enantioselectivities ranging from 91 to 98% ee were also achieved for challenging substrates such as unfunctionalized 1,1′-disubstituted olefins, functionalized tri- and 1,1′-disubstituted vinyl phosphonates, and β-cyclic enamides. The catalytic performance of the Ir-ligand assemblies was maintained when the environmentally benign 1,2-propylene carbonate was used as solvent. (Figure presented.).

Copper-catalyzed enantioselective conjugate reduction of α,β-unsaturated esters with chiral phenol–carbene ligands

A chiral phenol–NHC ligand enabled the copper-catalyzed enantioselective conjugate reduction of α,β-unsaturated esters. The phenol moiety of the chiral NHC ligand played a critical role in producing the enantiomerically enriched products. The catalyst worked well for various (Z)-isomer substrates. Opposite enantiomers were obtained from (Z)- and (E)-isomers, with a higher enantiomeric excess from the (Z)-isomer.

Enzymatic assembly of carbon–carbon bonds via iron-catalysed sp 3 C–H functionalization

Although abundant in organic molecules, carbon–hydrogen (C–H) bonds are typically considered unreactive and unavailable for chemical manipulation. Recent advances in C–H functionalization technology have begun to transform this logic, while emphasizing the importance of and?challenges associated with selective alkylation at a sp3 carbon1,2. Here we describe iron-based catalysts for the enantio-, regio- and chemoselective intermolecular alkylation of sp3 C–H bonds through carbene C–H insertion. The catalysts, derived from a cytochrome P450 enzyme in which the native cysteine axial ligand has been substituted for serine (cytochrome P411), are fully genetically encoded and produced in bacteria, where they can be tuned by directed evolution for activity and selectivity. That these proteins activate iron, the most abundant transition metal, to perform this chemistry provides a desirable alternative to noble-metal catalysts, which have dominated the field of C–H functionalization1,2. The laboratory-evolved enzymes functionalize diverse substrates containing benzylic, allylic or α-amino C–H bonds with high turnover and excellent selectivity. Furthermore, they have enabled the development of concise routes to several natural products. The use of the native iron-haem cofactor of these enzymes to mediate sp3 C–H alkylation?suggests that?diverse haem proteins could serve as potential catalysts for this abiological transformation, and will facilitate the development of new enzymatic C–H functionalization reactions for applications in chemistry and synthetic biology.

Giving a Second Chance to Ir/Sulfoximine-Based Catalysts for the Asymmetric Hydrogenation of Olefins Containing Poorly Coordinative Groups

This work identifies a family of Ir/phosphite-sulfoximine catalysts that has been successfully used in the asymmetric hydrogenation of olefins with poorly coordinative or noncoordinative groups. In comparison with analogue Ir/phosphine-sulfoximine catalysts previously reported, the presence of a phosphite group extended the range of olefins than can be efficiently hydrogenated. High enantioselectivities, comparable to the best ones reported, have been achieved for a wide range of olefins containing relevant poorly coordinative groups such as α,β-unsaturated enones, esters, lactones, and lactams as well as alkenylboronic esters.

Phosphite-thioether/selenoether Ligands from Carbohydrates: An Easily Accessible Ligand Library for the Asymmetric Hydrogenation of Functionalized and Unfunctionalized Olefins

A large family of phosphite-thioether/selenoether ligands has been easily prepared from accessible L-(+)-tartaric acid and D-(+)-mannitol and applied in the M-catalyzed (M=Ir, Rh) asymmetric hydrogenation of a broad number of substrates (46 in total). Its highly modular architecture has been crucial to maximize the catalytic performance. Improving most of the reported approaches, this ligand family presents a broad substrate scope. By selecting the ligand parameters high enantioselectivities (ee's up to 99 %) have therefore been achieved in a broad range of both, functionalized and unfunctionalized substrates. Interestingly, both enantiomers of the hydrogenation products can be usually achieved by changing the ligand parameters.

Catalytic, Enantioselective β-Protonation through a Cooperative Activation Strategy

The NHC-catalyzed transformation of unsaturated aldehydes into saturated esters through an organocatalytic homoenolate process has been thoroughly studied. Leveraging a unique “Umpolung”-mediated β-protonation, this process has evolved from a test bed for homoenolate reactivity to a broader platform for asymmetric catalysis. Inspired by our success in using the β-protonation process to generate enals from ynals with good E/Z selectivity, our early studies found that an asymmetric variation of this reaction was not only feasible, but also adaptable to a kinetic resolution of secondary alcohols through NHC-catalyzed acylation. In-depth analysis of this process determined that careful catalyst and solvent pairing is critical for optimal yield and selectivity; proper choice of nonpolar solvent provided improved yield through suppression of an oxidative side reaction, while employment of a cooperative catalytic approach through inclusion of a hydrogen bond donor cocatalyst significantly improved enantioselectivity.

N,N-Dimethylformamide as Hydride Source in Nickel-Catalyzed Asymmetric Hydrogenation of α,β-Unsaturated Esters

Asymmetric transfer hydrogenation of α,β-unsaturated esters is realized by using a nickel/bisphosphine catalyst and N,N-dimethylformamide (DMF) as the hydride source.

Nickel-catalyzed asymmetric transfer hydrogenation of conjugated olefins

Asymmetric transfer hydrogenation of electron-deficient olefins is realized with nickel catalysts supported by strongly σ-donating bisphosphines. Deuterium labeling experiments point to a reaction sequence of formate decarboxylation, asymmetric hydride in