Synthesis of new chiral cyclic 1,2-diamines and their evaluation as catalysts for enantioselective Diels–Alder reactions

The synthesis of new, enantiomerically pure cyclic 1,2-diamine structures was realized through a zinc promoted coupling of chiral bis-imines easily prepared starting from a chiral biphenyl dicarboxylic acid. The catalytic properties of such novel compounds were preliminarily studied; the trifluoroacetate salts of these chiral 1,2-diamines were shown to be able to catalyze the Diels–Alder reaction between cyclopentadiene and α,β-unsaturated aldehydes with good exo stereoselectivity and enantioselectivities up to 71%.