HCl/DMSO/HFIP-Mediated Chlorination of Pyrrolo[2,1-]isoquinolines and Other Electron-Rich Heteroarenes.

An efficient oxidative chlorination of pyrrolo[2,1-]isoquinolines has been established using HCl (aq) as the chlorine source and DMSO as the terminal oxidant in HFIP at ambient temperature. A variety of chlorinated pyrrolo[2,1-]isoquinoline derivatives have been prepared readily in 23 to 99% yields. This chlorination strategy can be expanded to the functionalization of other electron-rich heteroarenes including substituted pyrroles, indoles, and naphthols.

NHOAc/DMSO-Promoted Benzylation of Pyrrolo[2,1-]isoquinolines.

Benzylation of pyrrolo[2,1-]isoquinoline derivatives has been realized with various phenols by the use of ammonium acetate as a promoter (20 examples, up to 84% yield). DMSO served as the source of methylene and solvent. The employment of iron chloride as a catalyst can also afford the desired benzylated products in moderate to good yields (11 examples, up to a 74% yield).