Dearomative Synthesis of Chiral Dienes Enables Improved Late-Stage Ligand Diversification
Evan T Crawford1, Kendrick L Smith1, Jeffrey S Johnson1
1Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 25799-3290, United States.
Abstract:
An efficient synthesis of chiral nonracemic diene ligands is facilitated by an enantioselective dearomative intermolecular arene cyclopropanation of anisole. The functionality of the resulting cycloheptatriene engenders distinct chemical environments in a downstream tricyclic bis(enol) triflate that permits selective late-stage functionalization. The synthesis of diverse C1- and pseudo-C2-symmetric dienes is therefore viable by iterative palladium-catalyzed cross-coupling reactions. The ligands provide moderate to high selectivities in known Rh(I)-mediated asymmetric transformations.
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