Fig. 2: Design of axially chiral alkenylindole-fused nine-membered rings and synthetic strategy.

a Profile of catalytic atroposelective synthesis of axially chiral arylalkenes. b Design of axially chiral alkenylindole-fused nine-membered rings. c Bioactive molecules containing indole-fused nine-membered rings. d Profile of catalytic asymmetric (4 + 5) cycloadditions. e Our strategy for constructing axially chiral alkenylindole-fused nine-membered rings.