93922-52-2

Upstream product

• 104282-54-4 (R)-3-p-Tolyl-butyric acid (1R,2R,3S,4S)-3-[benzenesulfonyl-(3,5-dimethyl-phenyl)-amino]-1,7,7-trimethyl-bicyclo[2.2.1]hept-2-yl ester 
• 105526-87-2 (S)-1-((S)-3-p-Tolyl-butyryl)-5-trityloxymethyl-pyrrolidin-2-one 
• 192512-81-5 (R)-3-(4-methylphenyl)butanenitrile 
• 622-47-9 4-tolylacetic acid 
• 2417-95-0 p-tolyllithium 
• 106-38-7 para-bromotoluene 
• 106035-79-4 (R)-3-(4-methylphenyl)-1-butanol 
• 124-38-9 carbon dioxide 
• 93862-58-9 1-Methyl-4-((S)-1-methyl-2-phenylsulfanyl-ethyl)-benzene 
• 6305-61-9 ethyl (E)-3-p-tolylbut-2-enoate 
• 144782-30-9 (E)-3-(4-methylphenyl)but-2-enoyl chloride 
• 32147-13-0 3-(4-methylphenyl)-2-butenoic acid 
• 122-00-9 para-methylacetophenone 
• 4371-50-0 para-cymen-9-ol 

Downstream Products

• 848674-84-0 (R)-N-methyl-N-methoxy-3-(4-methylphenyl)butanamide 
• 106035-79-4 (R)-3-(4-methylphenyl)-1-butanol 
• 1141-54-4 (R)-2-methyl-6-(4-methylphenyl)-2-hepten-4-one 
• 93862-59-0 ethyl (R)-3-(4-methylphenyl)butanoate 

Relevant academic research and scientific papers

Enantioselective Copper-Catalyzed Methylboration of Alkenes

An enantioselective Cu-catalyzed borylative cross-coupling reaction of alkenes, bis(pinacolato)diboron (B2(pin)2), and methyl iodide is reported. Alkenes including styrenes, β-substituted styrenes, and challenging aliphatic olefins were smoothly transferred to the desired methylboration products with excellent diastereoselectivities (dr up to >99:1) and enantioselectivities (er up to 99:1). The utility of this process was demonstrated by the synthesis of naproxen and formal synthesis of two natural products.

Diastereoselective hydrogenation of α,β-unsaturated but-2-enamides to access the chiral 3-(p-tolyl) butanoic acids

An alternative methodology for the synthesis of chiral 3-(p-tolyl) butanoic acids is presented. This was accomplished through the diastereoselective hydrogenation reaction of different chiral N-3-(p-tolyl) but-2-enamides, using Pd/C in EtOH, to produce the corresponding chiral N-3-(p-tolyl) butanamides with high chemical yields and moderate diastereomeric ratios. Removal of the chiral auxiliary from N-3-(p-tolyl) butanamides gave the respective enantiomerically pure acids.

Rhodium/bisphosphine-thiourea-catalyzed enantioselective hydrogenation of α,β-unsaturated: N -acylpyrazoles

We successfully extended our Rh/bisphosphine-thiourea (ZhaoPhos) catalytic system to asymmetric hydrogenation of α,β-unsaturated N-acylpyrazoles affording products with high yields and excellent enantioselectivities (up to 97% yield, 99% ee). The pyrazole

Lipase-mediated resolution of substituted 2-aryl-propanols: Application to the enantioselective synthesis of phenolic sesquiterpenes

A comprehensive study of the lipase-mediated resolution of substituted 2-aryl-propanols is reported. The latter alcohols were submitted to the irreversible acetylation catalyzed either by PPL, CRL, or lipase PS. The enantioselectivity of these transformations was dependent on the type of lipase used. The type of substituents and particularly their position on the aromatic ring strongly affected the selectivity of the reaction. The experiments described prove that PPL is the more versatile lipase catalyzing the acetylation with an enantiomeric ratio (E) value that ranges from 1 up to 144, depending on the substrate used. Conversely, the same transformations were catalyzed by CRL and lipase PS with an enantiomeric ratio value, which is always less than 5. The remarkable behavior of PPL was exploited in the large scale resolution of some substituted 2-aryl-propanols whose enantiomeric forms are relevant building blocks in the enantioselective synthesis of phenolic sesquiterpenes. By these means, the synthesis of (S)-turmeronol B and the formal syntheses of (R)-curcumene, (R)-curcuphenol, (R)-xanthorrhizol, and (R)-curcuhydroquinone were accomplished.

Lipase catalysed kinetic resolutions of 3-aryl alkanoic acids

Hydrolase catalysed kinetic resolutions leading to a series of 3-aryl alkanoic acids (≥94% ee) are described. Hydrolysis of the ethyl esters with a series of hydrolases was undertaken to identify biocatalysts that yield the corresponding acids with excellent enantiopurity in each case. Steric and electronic effects on the efficiency and enantioselectivity of the biocatalytic transformation were also explored.

Enantioselective synthesis of (R)- and (S)-curcumene and curcuphenol: an efficient chemoenzymatic route

An efficient enantioselective synthesis of curcumene and curcuphenol is described. The key intermediates, substituted butanoates 7a and 7b and their acids 8a and 8b are obtained in high enantiopurity (>99% ee) by a lipase-catalyzed kinetic resolution proc

Organic synthesis in pheromone science

Examples are given to illustrate the use of chemical and/or enzymatic asymmetric reactions in the synthesis of the new pheromones of the broad-horned flour beetle, flea beetle, currant stem girdler and Colorado potato beetle. The relationships between ste

Synthesis of (R)-ar-turmerone and its conversion to (R)-ar-himachalene, a pheromone component of the flea beetle: (R)-ar-himachalene is dextrorotatory in hexane, while levorotatory in chloroform

(R)-ar-Turmerone was synthesized from (4-methylphenyl)acetic acid by employing Evans asymmetric alkylation as the key step. (R)-ar-Turmerone was converted to (R)-ar-himachalene, which was dextrorotatory in hexane while levorotatory in chloroform. Enantiomerically impure (75% ee) (R)-3-(4-methylphenyl)butanoic acid crystallized more readily than the enantiomerically pure one.

Determination of the Enantiomeric Excesses of Chiral Acids by 19F NMR Studies of their Esters deriving from (R)-(+)-2-(Trifluoromethyl)benzhydrol

15-Chiral acids were esterified with optically pure (R)-(+)-2-(trifluoromethyl)benzhydrol (R)-(+)-1, a readily available reagent.With respect to the carboxy group, the stereogenic centre is in the β-position in the case of the acids 5a-10a and 12a-16a, and in the α position in the case of the acids 17a-20a.The diastereomeric excesses of the corresponding esters 5b-10b and 12b-20b, respectively, were easily determined by means of 19F NMR.These d.e. values were in very good agreement with the e.e. values of the corresponding acids when the latter were known compounds.

ASYMMETRIC CONJUGATE ADDITION REACTION BY THE USE OF (S)-γ-TRITYLOXYMETHYL-γ-BUTYROLACTAM AS A CHIRAL AUXILIARY

(S)-γ-Trityloxymethyl-γ-butyrolactam (2) serves as a chiral auxiliary in the conjugate addition reaction of the corresponding imide (3) of α,β-unsaturated carboxylic acids with Grignard reagents in the presence of CuBr-SMe2 in THF to give, after hydrolysis, the β,β-disubstituted carboxylic acids (5) with predictable absolute configuration and high enantiomeric excess.