Synthesis of enantiomerically pure 2,9-dicycloalkyl substituted perhydro hexaazadibenzotetracenes

A one-pot synthesis of enantiomerically pure N,N'-dicycloalkyl substituted octadecahydro-1H,8H-2,3a,7b,9,10a,14b-hexaazadibenzo[fg,op]tetracenes has been successfully accomplished via the NiCl₂-catalyzed reaction between 1,3,5-tricycloalkyl-1,3,5-triazinanes and (R,R,R,R)- or (S,S,S,S)-perhydro-5,6,11,12-tetraazatetracenes (generated in situ from enantiopure trans-1,2-diaminocyclohexanes and glyoxal). The transformation may be regarded as the ‘trans-aminalization’ between cyclic aminals passing toward more stable products.