Angewandte Chemie International Edition
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Inside Cover: Asymmetric Catalysis on the Nanoscale: The Organocatalytic Approach to Helicenes (Angew. Chem. Int. Ed. 20/2014)
The asymmetric synthesis of helicenes by a Fischer indolization catalyzed by a SPINOL-derived phosphoric acid is reported by B. List et al. in their Communication on page 5202 ff. The catalyst is designed for long-range control and bears extended π-surfaces at the 3,3'-position. It creates a chiral nanometer-sized pocket, which enables π–π stacking interactions between the substituents and the reactive intermediate. A variety of (di)azahelicenes were obtained with good to excellent yields and enentioselectivities.