The first one-pot synthesis of L-7-iodotryptophan from 7-iodoindole and serine, and an improved synthesis of other L-7-halotryptophans.

A simple and scalable one-pot biotransformation enables direct access to L-halotryptophans, including L-7-iodotryptophan, from the corresponding haloindoles. The biotransformation utilizes an easy to prepare bacterial cell lysate that may be stored as the lyophilizate for several months and utilized as a catalyst as and when required.