16428-58-3

Upstream product

• 2510-99-8 ethyl 2-phenylpropanoate 
• 492-37-5 hydratropic acid 
• 168215-01-8 trideuteriomethyl 2-deuterio-2-phenylpropionate 
• 85020-76-4 methyl 2-deuterio-2-phenylpropionate 
• 31508-44-8 2-phenylpropionic acid methyl ester 

Downstream Products

• 937819-69-7 pentafluorophenyl 2-deuterio-2-phenyl-propionate 
• 7782-24-3 (S)-2-Phenylpropionic acid 
• 7782-26-5 (R)-2-Phenylpropionic acid 
• 931102-24-8 2-deuterio-2-phenylpropanoyl chloride 

Relevant academic research and scientific papers

COBALT-CATALYZED CARBONYLATION OF OPTICALLY ACTIVE AND α-DEUTERATED PHENETHYL HALIDES

Carbonylation of optically active α-phenethyl halides under phase transfer conditions gives hydratropic acid of the opposite absolute configuration.The inversion of configuration is accompanied by extensive racemization.The latter appears to originate from equilibria between keto and enol forms of acylcobalt-carbonyl complexes and between branched and linear alkyl complexes.Double carbonylation of α-phenethyl bromide is strongly inhibited when the benzylic hydrogen is replaced by deuterium.This large isotope effect provides the first experimental support for the proposed intermediacy of an enolic species in the double carbon monoxide insertion.

1,3,2-Diazaphospholenes Catalyze the Conjugate Reduction of Substituted Acrylic Acids

The potent nucleophilicity and remarkably low basicity of 1,3,2-diazaphospholenes (DAPs) is exploited in a catalytic, metal-free 1,4-reduction of free α,β-unsaturated carboxylic acids. Notably, the reduction occurs without a prior deprotonation of the carboxylic acid moiety and hence does not consume an additional hydride equivalent. This highlights the excellent nucleophilic character and low basicity of DAP-hydrides. Functional groups such as Cbz group or alkyl halides which can be problematic with classical transition-metal catalysts are well tolerated in the DAP-catalyzed process. Moreover, the transformation is characterized by a low catalyst loading, mild reaction conditions at ambient temperature as well as fast reaction times and high yields. The proof-of-principle for a catalytic enantioselective version is described.

New Strategy for Forging Contiguous Quaternary Carbon Centers via H 2 O 2 -Mediated Ring Contraction

Stereospecific construction of contiguous quaternary carbon centers constitutes a major challenge in natural product synthesis. A general protocol that enables stereospecific construction of all stereoisomers of such a moiety remains elusive. In this article, we will discuss the oxidative ring contraction of all-substituted cyclic α-formyl ketones mediated by H 2 O 2, which provides a facile access to the stereospecific construction of contiguous quaternary carbon centers.

Pd-Catalyzed Site-Selective p-Hydroxyphenyloxylation of Benzylic α-C(sp3)-H Bonds with 1,4-Benzoquinone

A Pd-catalyzed, site-selective p-hydroxyphenyloxylation of benzylic α-C(sp3)-H bonds with 1,4-benzoquinone using thioamide as a directing group is reported. 1,4-Benzoquinone is employed as the p-hydroxyphenyloxy source without extra oxidants. T

Oxidative rearrangement of malondialdehyde: Substrate scope and mechanistic insights

A novel oxidative rearrangement of malondialdehyde was described. Under the effect of H2O2, malondialdehyde smoothly transferred to carboxylic acid with C-C bond cleavage in good to excellent yields. Mechanistic studies showed that this reaction proceeded via the formation of a 1,2-dioxolane intermediate, followed by concert C-C, O-O, C-H bond cleavage and a hydride shift.

Engineering the promiscuous racemase activity of an arylmalonate decarboxylase

Variant G74C of arylmalonate decarboxylase (AMDase) from Bordatella bronchoseptica has a unique racemising activity towards profens. By protein engineering, variant G74C/V43A with a 20-fold shift towards promiscuous racemisation was obtained, based on a reduced activity in the decarboxylation reaction and a two-fold increase in the racemisation activity. The mutant showed an extended substrate range, with a 30-fold increase in the reaction rate towards ketoprofen. Molecular dynamics simulations and the substrate profile of the racemase indicate that the steric and polar effects of the substrate structure play a more dominant role on catalysis than mere kinetic α-proton acidity. The observation that the conversion of β,γ-unsaturated carboxylic acids does not lead to a rearrangement to form their α,β isomers indicates a concerted rather than a stepwise mechanism. Interestingly, a substrate bearing a nitro group instead of the carboxylic acid group on the α-carbon atom was also converted by the racemase.

An efficient laboratory synthesis of α-deuteriated profens

An efficient and practical laboratory synthesis of a series of 2-deuterio-2-arylpropionic acids (α-deuterioprofens) is described. The levels of deuterium incorporation are high and the products are synthetically useful. Copyright

Microbial deracemization of α-substituted carboxylic acids: Substrate specificity and mechanistic investigation

A new enzymatic method for the preparation of optically active α-substituted carboxylic acids is reported. This technique is called deracemization reaction, which provides us with a route to obtain the enantiomerically pure compounds, theoretically in 100% yield starting from the racemic mixture. This means that the synthesis of a racemate is almost equal to the synthesis of the optically active compound, and this concept is entirely different from the commonly accepted one in the asymmetric synthesis. Using the growing cell system of Nocardia diaphanozonaria JCM3208, racemates of 2-aryl- and 2-aryloxypropanoic acid are deracemized smoothly and (R)-form-enriched products are recovered in high chemical yield (>50%). In addition, using optically active starting compounds and deuterated derivatives as well as inhibitors, we have disclosed the fact that a new type of enzyme takes part in this biotransformation, and that the reaction proceeds probably via the same mechanism as that in rat liver.