Samarium(II) iodide-promoted hydroxyalkylations of indole 3-carbonyls. An expedient approach to pyrrolidino[1,2-a]indoles and furo[3,4-b]indoles

Abstract

3-Formyl-, 3-acetyl-1-methylindole and their 2-cyano analogues undergo intra- and inter-molecular hydroxyalkylations on treatment with samarium(II) iodide in the presence of a cosolvent hexamethylphosphoramide; the intramolecular coupling products have the structure prototype of mytomycins and the intermolecular coupling products are readily converted to furoindoles as synthetic equivalents of indole-2,3-quinodimethanes.