The Bischler indole synthesis, discovered over 100 years ago,1 involves the reaction of anilines with α-halo-ketones or -acetals and the subsequent acid catalysed cyclisation of the resulting α-(N-arylamino)- ketones or -acetals (the Nordlander modification).2,3 We now report a modification in which the key step is the NH insertion reaction4 of anilines with rhodium carbenoids generated from diazocarbonyl compounds to give α-(N-arylamino)ketones for subsequent cyclisation.5
[Bashford, Katherine E.; Cooper, Anthony L.; Kane, Peter D.; Moody, Christopher J.; Muthusamy, Sendogagounder; Swanna, Elizabeth Journal of the Chemical Society. Perkin Transactions 1, 2002 , # 14 p. 1672 - 1687]
