Stereoselective Pd-Catalyzed Remote Hydroamination of Skipped Dienes with Azoles

Abstract

A novel palladium-catalyzed stereoselective remote hydroamination reaction is disclosed. A series of azoles and skipped dienes undergo the migratory allylic C-H amination in good yields and selectivities. A desymmetric migratory azolation process is also developed to highlight the reliability of the transformation. Preliminary mechanistic experiments corroborate the designed metal walking and allylic substitution cascade strategy via PdH catalysis, different from prior ligand-to-ligand hydrogen transfer pathway for conjugated dienes.

Kinetic Resolution of N-Allylic Pyrazoles via Photoexcited Chiral Copper Complex-Catalyzed Alkene E → Z Isomerization

“…Consequently, the synthesis of enantioenriched N -allylic pyrazole derivatives, particularly Z -allylic pyrazoles, is of paramount importance and presents an intriguing synthetic challenge. Various strategies have been developed for the efficient construction of racemic N -allylic azoles, including allylic substitution, hydroamination of allenes/alkynes with azoles, and oxidation cross-couplings (Figure a). − However, the enantioselective synthesis of N -allylic pyrazoles remains relatively underexplored. Breit achieved Rh- or Pd-catalyzed asymmetric hydroamination of allenes with pyrazoles, while Dong achieved enantioselective addition of pyrazoles to conjugated dienes catalyzed by a Pd complex (Figure b) .…”