Exploration of Aberrant Behaviour of Grignard Reagents with Indole-3-carboxaldehyde: Application to the Synthesis of Turbomycin B and Vibrindole A Derivatives

An aberrant reaction of Grignard reagents with N-alkylated indole-3-carboxaldehyde has been observed. Contrary to the usual formation of an alcohol, it afforded an unusual bis(indolyl)methane product. A systematic study on this new mode of reactivity and its application to a synthesis of the potent antibiotic turbomycin B and vibrindole A derivatives is reported.