One-step synthesis of Optically Active Cyclic Polyamines Containing Helicene

摘要

Chiral macrocyclic tetraamines containing four helicenes were effectively synthesized in one-step. Reductive coupling of a (P)-helicenedi(methylamine) and a (P)-helicenedicarbaldehyde gives a cyclic (P,P,P,P)-tetramer in 88% yield. The (P,M,P,M)-diastereomer was effectively synthesized from the (M)-diamine and the (P)-dialdehyde in 66% yield. The intermediate (P,P,P,P)-imine and (P,M,P,M)-imine can be isolaed also in high yields. The reductive coupling of achiral arenes, m-phenylenedi(methylamine) and m-phenylenedicarbaldehyde gives the cyclic tetramer in 47% yield, which is accompanied by the higher cyclic oligomers containing hexamer (18%) and occtamer (3%). The condensed benzene ring system of the helicene appears to play an important role in the high yielding cyclic tetramerization.