Practical methodologies for the synthesis of indoles

To synthetic chemists who design industrial or manufacturing syntheses as well as researchers in academia, the implementation of practical, safe, and scalable methods for the large-scale preparation of indoles is of critical interest. This review highlights the practical methodologies which have either been successfully demonstrated or are potentially useful for the large-scale synthesis of indoles. Reaction methodologies that have appeared in the scientific literature between 1995 and June 2005 are discussed with emphasis on those reactions leading to the indole ring.