Synthesis of granulatimide positional analogues

The Stille coupling reaction of the stannylindole 13 with the 5-iodoimidazole derivative 14 (or 27) in the presence of PdCl(2)(PPh(3))(2) gave the corresponding indole-imidazole coupling product 15 (or 28), thereby affording a synthetic approach to 10-methylgranulatimide (7), 15-methylgranulatimide (11), and 10, 15-dimethylgranulatimide (12), as well as 10-methylisogranulatimide B (5).