Organic Letters 2002-08-08

A one-pot access to 6-substituted phenanthridines from fluoroarenes and nitriles via 1,2-arynes.

Jan Pawlas, Mikael Begtrup

Index: Org. Lett. 4(16) , 2687-90, (2002)

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Abstract

[reaction: see text] A one-pot, t-BuLi-induced synthesis of 6-substituted phenanthridines from fluoroarenes and nitriles via 1,2-arynes is reported. Aryl- and hetaryl nitriles, cyanamides, and trimethylacetonitrile gave phenanthridine products. The method was extended to provide bisphenanthridine 10 by a one-pot bis-cyclization, using 1,3-dicyanobenzene and PhF in 1:5 ratio. Reaction of 1-fluoronaphthalene and 4-chlorofluorobenzene with benzonitrile afforded the regioisomerically pure products 11 and 12, respectively.