Organocatalytic Activation of Donor-Acceptor Cyclopropanes: A Tandem (3+3)-Cycloaddition/Aryl Migration toward the Synthesis of Enantioenriched Tetrahydropyridazines
Anorganocatalytic enantioselective (3 + 3)-cycloaddition reactionof racemic cyclopropane carbaldehydes and aryl hydrazones has beendemonstrated for the first time. A wide range of enantioenriched tetrahydropyridazineswith an exocyclic double bond were obtained with moderate to goodyields and good to excellent enantiomeric excesses. Mechanistic investigationshinted toward a matched/mismatched kinetic resolution, and controlexperiments and DFT calculations unveiled that 1,3-aryl migrationwas concerted and intramolecular and proceeds via a four-memberedtransition state.
机构:
CSIR, Natl Chem Lab, Div Organ Chem, Dr Homi Bhabha Rd, Pune 411008, Maharashtra, India
Acad Sci & Innovat Res AcSIR, 2 Rafi Marg, New Delhi 110002, IndiaCSIR, Natl Chem Lab, Div Organ Chem, Dr Homi Bhabha Rd, Pune 411008, Maharashtra, India