Ligand-Free Iron-Catalyzed C-F Amination of Diarylamines: A One-Pot Regioselective Synthesis of Diaryl Dihydrophenazines

Yuma Aoki; Harry M O'Brien; Hiroto Kawasaki; Hikaru Takaya; Masaharu Nakamura

doi:10.1021/acs.orglett.8b03702

Ligand-Free Iron-Catalyzed C-F Amination of Diarylamines: A One-Pot Regioselective Synthesis of Diaryl Dihydrophenazines

Org Lett. 2019 Jan 18;21(2):461-464. doi: 10.1021/acs.orglett.8b03702. Epub 2019 Jan 10.

Authors

Yuma Aoki^{1

2}, Harry M O'Brien³, Hiroto Kawasaki^{1

2}, Hikaru Takaya^{1

2}, Masaharu Nakamura^{1

2}

Affiliations

¹ International Research Center for Elements Science, Institute for Chemical Research , Kyoto University , Uji, Kyoto 611-0011 , Japan.
² Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering , Kyoto University , Nishikyo-ku, Kyoto 615-8510 , Japan.
³ School of Chemistry , University of Bristol , Cantock's Close , Bristol BS8 1TS , U.K.

PMID: 30628796
DOI: 10.1021/acs.orglett.8b03702

Abstract

A one-pot synthesis of various 5,10-diaryl-5,10-dihydrophenazines (DADHPs) from diarylamines has been achieved by using an iron-catalyzed C-F amination. Homodimerization of magnesium diarylamides, followed by defluorinative intramolecular cyclization (double ortho C-F amination) in the presence of catalytic FeCl₂ and stoichiometric 1,2-dibromoethane, affords the corresponding DADHPs with complete regiocontrol. The unique high reactivity of fluorine over other halogens indicates that amination proceeds via an S_NAr mechanism facilitated by iron.

Publication types

Research Support, Non-U.S. Gov't