Reduction of the indole ring system: Synthesis of 4,5,6,7-tetrahydroindoles

Article abstract of DOI:10.1016/S0040-4039(99)01687-1

A general two-step procedure for the reduction of indoles to the corresponding 4,5,6,7-tetrahydroindoles has been developed. A regioselective Birch reduction followed by catalytic hydrogenation is employed to accomplish this transformation. Yields for the sensitive pyrrole products are typically between 40 and 50%. This method provides access to complex chiral pyrroles that cannot be readily prepared by other methods.