88254-01-7

Upstream product

• 34009-61-5 diethyl 2-methyl-2-phenylmalonate 
• 124-38-9 carbon dioxide 
• 22286-82-4 2-phenyl-acrylic acid ethyl ester 
• 492-38-6 2-phenylacrylic acid 

Downstream Products

• 2510-99-8 ethyl 2-phenylpropanoate 
• 7782-24-3 (S)-2-Phenylpropionic acid 
• 7782-26-5 (R)-2-Phenylpropionic acid 

Relevant academic research and scientific papers

Computational and Experimental Insights into Asymmetric Rh-Catalyzed Hydrocarboxylation with CO2

The asymmetric Rh-catalyzed hydrocarboxylation of α,β-unsaturated carbonyl compounds was originally developed by Mikami and co-workers but gives only moderate enantiomeric excesses. In order to understand the factors controlling the enantioselectivity and to propose novel ligands for this reaction, we have used computational and experimental methods to study the Rh-catalyzed hydrocarboxylation with different bidentate ligands. The analysis of the C?CO2 bond formation transition states with DFT methods shows a preference for outer-sphere CO2 insertion, where CO2 can undergo a backside or frontside reaction with the nucleophile. The two ligands that prefer a frontside reaction, StackPhos and tBu-BOX, display an intriguing stacking interaction between CO2 and an N-heterocyclic ring of the ligand (imidazole or oxazoline). Our experimental results support the computationally predicted low enantiomeric excesses and highlight the difficulty in developing a highly selective version of this reaction.

Rhodium-Catalyzed Hydrocarboxylation of Olefins with Carbon Dioxide

The catalytic hydrocarboxylation of styrenes derivatives and α,β-unsaturated carbonyl compounds with CO2(101.3 kPa) in the presence of an air-stable rhodium catalyst was explored. The combination of [RhCl(cod)]2(cod = cyclooctadiene) as a catalyst and diethylzinc as a hydride source allowed for effective hydrocarboxylation and provided the corresponding α-aryl carboxylic acids in moderate to excellent yields. In this catalytic process with carbon dioxide, intervention of the RhI–H species, which could be generated from the RhIcatalyst and diethylzinc, was clarified. Significantly, the catalytic asymmetric hydrocarboxylation of α,β-unsaturated esters with carbon dioxide was also performed by employing a cationic rhodium complex possessing (S)-(–)-4,4′-bi-1,3-benzodioxole-5,5′-diylbis(diphenylphosphine) [(S)-SEGPHOS] as a chiral diphosphine ligand. A plausible model for asymmetric induction was proposed by determination of the absolute configuration of the product.

Substrate specificity of an esterase from the archaeon Sulfolobus tokodaii bearing a GGG(A)X motif

A GGG(A)X-type esterase (Est0071) from an archaeon catalyzes asymmetric hydrolysis of prochiral bulky malonic diesters in good enantioselectivity. The selectivity of Est0071 was for the opposite enantiomer to that previously shown for pig liver esterase, and the resulting enantiomeric excess of the products was higher. Est0071 could also catalyze the hydrolysis of various acetates of secondary alcohols, and showed moderate enantioselectivity in these reactions.

Thermally driven asymmetric domino reaction catalyzed by a thermostable esterase and its variants

We have developed a thermally driven domino reaction for the synthesis of (S)-a-arylpropionates (profens) using a thermostable esterase from Sulfolobus tokodaii strain 7. Stereoselectivity was improved considerably by engineering of the active site. Stereoselective decarboxylation at the active site of an esterase is a new reaction for the synthesis of optically active carboxylic acids. Crown Copyright.

Improved process for the enantioselective hydrolysis of prochiral diethyl malonates catalyzed by pig liver esterase

An improved process for the enantioselective hydrolysis of prochiral 2-aryl-2-alkyl-disubstituted diethyl malonates catalyzed by pig liver esterase (PLE) was developed. With diethyl 2-phenyl-2-methylmalonate as a model substrate, the highest enantioselect

Enzymatic enantioselective ester hydrolysis by carboxylesterase NP

The enzymatic hydrolysis of a series of carboxylic esters by carboxylesterase NP has been investigated in order to determine the scope and limitations of this enzyme. 2-Substituted propionates were hydrolyzed with high enantioselectivity when an aromatic moiety was part of the 2-substituent.Enantioselective hydrolysis could be accomplished with several 2-arypropionates, 2-(aryloxy)propionates and N-arylalanine esters.The propionate esters yielded propionic acids as (S) enantiomers, whereas the alanine esters yielded the (R) enantiomers.Without a 2-aryl substituent, the enzymatic hydrolysis of the propionates occurred at a lower rate without acceptable enantioselectivity.In addition to 2-substituted propionates, only a few other esters were hydrolyzed with high enantioselectivity by carboxylesterase NP, such as some prochiral disubstituted malonates. 1-Phenylethylacetate was the only substrate with chirality in the alcohol part of the ester that was found to be hydrolyzed enantioselectively.Carboxylesterase NP proved to be a powerful enzyme for kinetic resolution of propionate esters with an aromatic ring containing a 2-substituent.