Regio- and enantioselective synthesis of N-substituted pyrazoles by rhodium-catalyzed asymmetric addition to allenes.

摘要: The rhodium-catalyzed asymmetric N-selective coupling of pyrazole derivatives with terminal allenes gives access to enantioenriched secondary and tertiary allylic pyrazoles, which can be employed for the synthesis medicinally important targets. reaction tolerates a large variety functional groups labelling experiments gave insights into mechanism. This new methodology was further applied in highly efficient JAK 1/2 inhibitor (R)-ruxolitinib.