| Abstract
| - The chiral bisamidine 5 has been prepared in just two steps from malonodinitrile. In the monocationicform this compound adopts a planar conformation with an almost convergent orientation of two N−Hgroups. Ketones, aldehydes, and nitro compounds are assumed to bind to this strongly polar cleft viahydrogen bonds, resulting in a Lewis-acid-like activation of the carbonyl groups. A broad scope of reactions(Diels−Alder, hetero-Diels−Alder, Friedel−Crafts) can be catalyzed. The observed accelerations surpassthe rate effects of neutral hydrogen-bond donors such as thioureas or TADDOLs.
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