Point-to-helical chirality transfer for a scalable and resolution-free synthesis of a helicenoidal DMAP organocatalyst

摘要

The synthesis of a second-generation [6]-heIicenoidaI DMAP organocatalyst is reported. The synthesis is reliant upon a highly diastereoselective Rh-catalysed [2 + 2 + 2] triyne cycloisomer-ization, using an existing stereocentre to control the sense of forming helicity. Taken together, a scalable (> 1 g), resolution-free entry to a helical DMAP with the capacity for subsequent functionalization, has been achieved.