ol9b02520_si_001.pdf (13.18 MB)
Pummerer Synthesis of Chromanes Reveals a Competition between Cyclization and Reductive Chlorination
journal contribution
posted on 2019-08-23, 12:08 authored by Paola Acosta-Guzmán, Alvaro Rodríguez-López, Diego Gamba-SánchezThe competition between
an unprecedented reductive chlorination
and the Pummerer reaction was studied and applied to the synthesis
of benzofused oxygen heterocycles including 3-aminochromanes and in
the intramolecular chlorination of activated aromatic rings. The use
of (COCl)2 as a Pummerer activator showed substantial activity,
producing α-chlorinated sulfides that can undergo Pummerer–Friedel–Crafts
cyclization. If the aromatic ring has electron-donating groups in
position three, then the reaction follows a different pathway, yielding
the reductive chlorination products, where the chlorine atom comes
from a sulfonium salt.