# C-2 functionalization of indoles with xanthate-lactam derivatives by radical-oxidative coupling, an approach to Aspidosperma alkaloids

## TL;DR

A new method for modifying indoles at the C-2 position using xanthate-lactam derivatives is developed, enabling the synthesis of complex alkaloids like those found in Aspidosperma.

## Contribution

A radical-oxidative coupling approach for C-2 functionalization of indoles using xanthate-lactam derivatives is introduced.

## Key findings

- Xanthate precursors from lactams enable C-2 alkylation of indoles.
- The method was successfully applied to synthesize 1,2-dehydroaspidospermidine.
- Key intermediates for indole-monoterpene alkaloids were efficiently produced.

## Abstract

The C-2 functionalization of various indole derivatives via radical-oxidative coupling is presented. The xanthate precursors utilized as alkylating agents are derived from two distinct lactams, which are of considerable significance due to their presence in numerous monoterpenoid indole alkaloids, such as Aspidosperma and ibophyllidine types. The synthesis of 1,2-dehydroaspidospermidine exemplifies the application of this methodology.

Key intermediates in the total synthesis of indole-monoterpene alkaloids were obtained from a C2-radical alkylation of indoles using lactam-derived xanthates.