90773-72-1Relevant academic research and scientific papers
Hydrogen/deuterium isotopic labeling study of enantioselective hydrogenation of (E)-2-Methyl-2-butenoic acid over a cinchonidine-modified Pd/C catalyst
Sugimura, Takashi,Tomatsuri, Satoshi,Fujita, Morifumi,Okamoto, Yasuaki
, p. 1737 - 1742 (2019)
In the enantioselecitve hydrogenation of (E)-2-methyl-2butenoic acid (1) over a cinchonidine-modified Pd/C catalyst, the addition of hydrogen preferentially proceeds from the Re-Si enantioface of the C=C double bond of 1 to yield (S)-2methylbutanoic acid ((S)-3). Double bond migration of 1 takes place under the reaction conditions and is followed by immediate hydrogenation to yield 3 in a poor enantiomeric purity. Deuterium labeling experiments at 0.1 MPa and 1.9 MPa of D2verified the previous assumption of competitive double bond migration. The combination of isotopic labeling experiments and chiral analysis revealed that the double bond migration of 1 proceeds with the same enantiofacial differentiation as the hydrogenation of 1. Thus, interaction of 1 with cinchonidine adsorbed on the Pd surface may control the configuration of the double bond migration and the hydrogenation.
