21034-27-5

Upstream product

• 622-97-9 1-ethenyl-4-methylbenzene 
• 64-19-7 acetic acid 
• 74137-20-5 1-<2,3-epoxy-3-(trimethylsilyl)propyl>-p-tolylcarbinol 
• 42249-98-9 1-(4-methylphenyl)-3-butyn-1-ol 
• 104-87-0 4-methyl-benzaldehyde 
• 78861-19-5 Methyl 3-bromo-4-keto-4-(4'-methylphenyl)butanoate 
• 4619-20-9 3-(4-methylbenzoyl)propionic acid 
• 108-88-3 toluene 
• 78861-22-0 Methyl (E)-4-hydroxy-4-(4'-methylphenyl)but-2-enoate 
• 57498-54-1 methyl 4-(4-methylphenyl)-4-oxobutanoate 
• 66528-97-0 (E)-<3-(trimethylsilyl)allyl>-p-tolylcarbinol 
• 4521-22-6 4-(4-methylphenyl)butyric acid 
• 74137-27-2 2-methoxy-5-p-tolyltetrahydrofuran 
• 32149-28-3 Methyl 4-keto-4-(4'-methylphenyl)but-2-enoate 

Downstream Products

• 100607-64-5 4-Chloe-4-p-tolyl-buttersaeureethylester 
• 84487-28-5 4-Benzyl-5-phenyl-1-p-tolyl-pentane-1,4-diol 
• 4521-21-5 dihydro-5-(4-methylphenyl)-2(3H)-thiophenone 
• 18456-66-1 (1R*,2R*)-ethyl 2-(p-tolyl)cyclopropanecarboxylate 
• 84487-30-9 Acetic acid 4-benzyl-4-hydroxy-5-phenyl-1-p-tolyl-pentyl ester 
• 84487-37-6 Acetic acid 4-oxo-5-phenyl-1-p-tolyl-pentyl ester 

Relevant academic research and scientific papers

Efficient hydrogenation of levulinic acid catalysed by spherical NHC-Ir assemblies with atmospheric pressure of hydrogen

A practical, efficient, and mild hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) under 1 atm H2was realized by single-sited 3D porous self-supported N-heterocyclic carbene iridium catalysts. Quantitative yields and selectivities were achieved at 0.02 mol% catalyst loading, and the catalyst could be reused for 9 runs without obvious loss of selectivity or activity.

Photo-induced radical borylation of hemiacetals via C–C bond cleavage

In this study, we reported a photo-induced radical borylation of hemiacetal derivatives via C–C bond cleavage. This transformation can be realized under mild conditions with simple reaction settings and irradiation of visible light. A series of substrates, including both cyclic and linear hemiacetal derivatives, were effectively transformed to the borylation product in moderate to good yields. Finally, the mechanism was studied in detail by DFT calculations, suggesting insight of the radical borylation process.

One-Pot γ-Lactonization of Homopropargyl Alcohols via Intramolecular Ketene Trapping

A one-pot γ-lactonization of homopropargyl alcohols via an alkyne deprotonation/boronation/oxidation sequence has been developed. Oxidation of the generated alkynyl boronate affords the corresponding ketene intermediate, which is trapped by the adjacent hydroxy group to furnish the γ-lactone. We have optimized the conditions as well as examined the substrate scope and synthetic applications of this efficient one-pot lactonization.

Biocatalytic Asymmetric Reduction of γ-Keto Esters to Access Optically Active γ-Aryl-γ-butyrolactones

An efficient stereoselective syntheses of a series of functionalized optically active γ-aryl-γ-butyrolactones is achieved by enzymatic asymmetric reduction of the corresponding sterically demanding γ-keto esters employing wild-type and recombinant alcohol dehydrogenases. The best stereoselectivities for the reduction via hydrogen transfer was obtained with two short chain dehydrogenases (SDRs) of complementary stereospecificity from Aromatoleum aromaticum, namely the Prelog-specific NADH-dependent (S)-1-phenylethanol dehydrogenase [(S)-PED] and the anti-Prelog-specific (R)-1-(4-hydroxyphenyl)-ethanol dehydrogenase [(R)-HPED], respectively.Biotransformations catalyzed by both enzymes, followed by TFA-catalyzed cyclization of the resulting γ-hydroxy esters, furnished the respective (S)- and (R)-configured products with exquisite optical purity (up to >99% ee). The synthetic value was demonstrated on preparative scale for the asymmetric bioreduction of the model compound, methyl 4-oxo-4-phenylbutanoate, affording optically pure (S)-γ-phenyl-γ-butyrolactone (>99% ee) in 67–74% isolated yield at 89–95% conversion depending on the applied scale. (Figure presented.).

Cooperative iodine and photoredox catalysis for direct oxidative lactonization of carboxylic acids

A new method for the formation of γ- and δ-lactones from carboxylic acids through direct conversion of benzylic C-H to C-O bonds is described. The reaction is conveniently induced by visible light and relies on a mild cooperative catalysis by the combination of molecular iodine and an organic dye.

Synthesis of Enantiopure γ-Lactones via a RuPHOX-Ru Catalyzed Asymmetric Hydrogenation of γ-Keto Acids

A RuPHOX?Ru catalyzed asymmetric hydrogenation of γ-keto acids has been developed, affording the corresponding enantiopure γ-lactones in high yields and with up to 97% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 10000 S/C) under the indicated reaction conditions and the resulting products can be transformed to several enantiopure building blocks, biologically active compounds and enantiopure drugs. (Figure presented.).

Catalytic Redox Chain Ring Opening of Lactones with Quinones to Synthesize Quinone-Containing Carboxylic Acids

Catalytic ring opening of five- to eight-membered lactones with quinones is achieved through a redox chain mechanism. With low loading of a simple metal triflate Lewis acid catalyst and a chain initiator, C-H bonds of many quinones were efficiently functionalized with carboxylic acid-containing side chains. This method also features 100% atom economy and wide substrate scope. A novel route to the anti-asthma drug Seratrodast was developed. Mechanism study suggests that the redox chain reaction likely undergoes a carbocation intermediate.

Indium-Catalyzed Direct Conversion of Lactones into Thiolactones and Selenolactones in the Presence of Elemental Sulfur and Selenium

The direct conversion of lactones into thiolactones with elemental sulfur (S 8) catalyzed by InCl 3 /PhSiH 3 in a one-pot reaction is described. This catalytic system was successfully applied to the novel preparation of selenolactones from lactones and selenium.

Efficient Hydrogenation of Biomass Oxoacids to Lactones by Using NHC–Iridium Coordination Polymers as Solid Molecular Catalysts

A series of NHC–iridium coordination polymers have proven to be robust, efficient and recyclable solid molecular catalysts toward the hydrogenation of biomass levulinic acid (LA) to γ-valerolactone. Along with quantitative yields attained at 0.01 mol % catalyst loading under 50 atm of H2, the solid molecular catalyst was readily recovered and reused for 12 runs without obvious loss of the selectivity and activity. Remarkably, up to 1.2×105 TON, an unprecedented value could be achieved in this important transformation. In addition, a number of LA homologues, analogues and derivatives were well tolerated to deliver various intriguing and functional lactones in good to excellent yields, which further confirmed the feasibility of the solid molecular catalysts.

Asymmetric Organocatalytic One-Pot, Two-Step Sequential Process to Synthesize Chiral Acetal-Containing Polycyclic Derivatives from Cyclic Hemiacetals and Enones

We have developed an efficient one-pot, two-step sequential process to synthesize biologically and synthetically important chiral acetal-containing polycyclic derivatives. This novel protocol had been proved to proceed via Michael-lactolization-oxocarbenium ion ring-closing sequence, which was initiated by a key reactive enamine intermediate and interrupted the previously established reaction pathway of two different enones used in this work, and generated the corresponding cycloadducts with excellent stereoselectivity bearing up to seven continuous stereocenters. Both chiral and racemic starting cyclic hemiacetals worked well in this strategy. The synthetic applications of the obtained polycyclic products have also been demonstrated.