A General Approach to Optically Pure [5]-, [6]-, and [7]Heterohelicenes

Abstract

A general method for the preparation of optically pure [5]-, [6]-, and [7]heterohelicenes is based on a CoI- or Ni0-catalyzed diastereoselective [2+2+2] cycloisomerization of centrally chiral triynes to deliver helicenes comprising two 2H-pyran rings. The configuration, which can be predicted, does not depend on helicene length or functional groups present.

Keywords

• aromatic compounds
• asymmetric synthesis
• chirality
• helical structures
• heterocycles