170432-99-2

Upstream product

• 67-64-1 acetone 
• 405-50-5 p-Fluorophenylacetic acid 
• 193673-85-7 2-(p-fluorophenyl)-3-hydroxy-3-methylbutyric acid 

Downstream Products

• 55332-37-1 (2S)-2-(4-fluorophenyl)-3-methylbutanoic acid 
• 110311-45-0 [R]-(-)-2-(p-fluorophenyl)-3-methylbutyric acid 
• 1354651-16-3 C₁₁H₁₂⁽²⁾HFO₂ 

Relevant academic research and scientific papers

Iridium-catalyzed enantioselective hydrogenation of α,β- unsaturated carboxylic acids with tetrasubstituted olefins

A highly efficient asymmetric hydrogenation of α,β-unsaturated carboxylic acids with tetrasubstituted olefin catalyzed by chiral spiro iridium complexes has been developed for the preparation of chiral α-substituted carboxylic acids in excellent enantioselectivities (up to 99% ee).

Process for making α,β-unsaturated carboxylic acids

α, β-Unsaturated acids of the formula STR1 wherein R1 signifies C1 -C5 -alkyl and Ar signifies an aryl group which is optionally substituted by one or more substituents selected from the group consisting of halogen, phenyl, C1 -C5 -alkyl, C1 -C5 -alkoxy, perfluorinated C1 -C5 -alkyl or perfluorinated C1 -C5 -alkoxy can be obtained from new or known compounds of the formula STR2 Compounds I can be converted by asymmetric hydrogenation into corresponding optically active saturated acids.

Practical synthesis of (S)-2-(4-fluorophenyl)-3-methylbutanoic acid, key building block for the calcium antagonist Mibefradil

A short, technically feasible route was developed for the synthesis of (S)-2-(4-fluorophenyl)-3-methylbutanoic acid (S)-2 with an overall yield of 80% starting from 4-fluorophenylacetic acid. Asymmetric hydrogenation of the easily accessible unsaturated acid 3 in the presence of ruthenium(II) carboxylato complexes containing chiral atropisomeric diphosphines afforded (S)-2 in up to 94% ee. The ee of (S)-2 was upgraded to 98% by crystallization of its sodium salt. The same protocol was also applied to the synthesis of (S)-2-(4-chlorophenyl)-3-methylbutanoic acid.