Carbolithiation of Vinyl Pyridines as a Route to 7-Azaindoles
B. Cottineau, D. F. O’Shea*
University College Dublin, Ireland
21 September 2005 (online)
This paper provides a new and efficient synthetic route to functionalized 7-azaindoles. The Suzuki carbolithiation/intramolecular Madelung-type sequence leads to indoles with R2 = n,- s-, t-Bu and R3 = Ph, t-Bu, C4H3S groups with little variation at R1 = H, Me substitution. It is a considerable improvement over several other methods for the synthesis of 2,3-substituted indoles such as Fischer indole and Madelung reactions.