C₂-symmetric N,N′-bis(terpenyl)ethylenediamines - Synthesis and application in the enantioselective nitroaldol reaction

Optically pure C₂-symmetric chiral diamines, have been synthesized by the reaction of terpenylamines with diethyloxalate, followed by the reduction of diamide with BH₃-BF₃. The methodology has been successfully applied and high yields achieved in the synthesis of chiral diamines derived from terpenes such as α-pinene, β-pinene, and 2-iso- and 4-carenes. These chiral diamines are found to be to be highly effective in inducing chirality in the nitroaldol reaction.