The enantioselective synthesis of azahelicenes and S-shaped double azahelicenes has been achieved via the Au-catalyzed sequential intramolecular hydroarylation of alkynes. The use of excess AgOTf toward a Au(I) complex is crucial for this transformation. Interestingly, the circularly polarized luminescence activity of the S-shaped double azahelicenes was significantly higher than that of the azahelicenes.

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SummaryIt has been established that a cationic gold(I)/(R)-DTBM-Segphos or (R)-BINAP complex catalyzes the atropselective intramolecular hydroarylation of alkynes leading to enantioenriched axially chiral 4-aryl-2-quinolinones and 4-arylcoumarins with up to 61% ee.

Scheme 3. Possible mechanism for the formation of 2 from 1. Scheme 4. Platinum-catalyzed reaction of [D 5 ]-1 a. Scheme 5. Platinum-catalyzed reaction of 1 a in the presence of CD 3 OD. Scheme 6. Platinum-catalyzed reaction of 1 m with a trifluoromethyl substituted electron-deficient benzyl group. Scheme 7. Hydrogenation of dearomatized product 2 a. Angewandte Chemie 6325

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