The use of sulfur ylides in the synthesis of substituted indoles.

[reaction: see text] This letter describes the insertion of rhodium carbenoids into thioindoles. C-10 thioindoles undergo fragmentation-coupling reactions when exposed to rhodium carbenoids. In an analogous fashion, ketoester- and malonate-substituted carbenoids have been found to insert into C-2 thioindoles. In contrast, vinylogous carbenoids were found to alkylate C-2 thioindoles at C-3.