The use of a new carboranylamidophosphite ligand in the asymmetric Rh-catalyzed hydrogenation of α- and β-dehydroamino acid derivatives

New chiral carboranylamidophosphite ligand was synthesized and tested in the Rh-catalyzed asymmetric hydrogenation of α- and β-dehydroamino acid derivatives (up to 93% ee). The catalytic performance is affected greatly by temperature and the nature of solvents. Importantly, we have shown that in the hydrogenation of the β-dehydroamino acid derivatives the use of acidic 1,1,1,3,3,3-hexafluoro-2-propanol led to a significant increase in the enantioselectivity, compared to isopropyl alcohol.

Graphical abstractNew chiral carboranylamidophosphite ligand was synthesized and tested in the Rh-catalyzed asymmetric hydrogenation of α- and β-dehydroamino acid derivatives (up to 93% ee). The catalytic performance is affected greatly by temperature and the nature of solvents. Importantly, we have shown that in the hydrogenation of the β-dehydroamino acid derivatives the use of acidic 1,1,1,3,3,3-hexafluoro-2-propanol led to a significant increase in the enantioselectivity, compared to isopropyl alcohol.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► A new carboranylamidophosphite ligand was synthesized. ► Reaction of the ligand with [Rh(COD)2]BF4 afforded cationic rhodium complex. ► The new ligand was used in Rh-catalyzed hydrogenation. ► The catalytic performance is affected greatly by temperature and solvent acidity.