Mimicking enzymatic cation-π interactions in hydrazide catalyst design: access to trans -decalin frameworks.

Chiral bicyclic hydrazide organocatalysts have previously been shown to catalyze the cyclization of ( Z )-polyene substrates with high enantioselectivity, but with poor selectivity for the corresponding ( E )-polyenes. Here we demonstrate that diazapane carboxylates bearing terphenyl groups efficiently catalyze ( E )-polyene bicyclization with enantioselectivities up to 94 : 6 er and with high diastereoselectivity for trans -decalin formation. The catalysts function by simultaneously initiating the cyclization via iminium ion formation and stabilizing intermediates/transition states by cation-π interactions.