Directed regioselective ortho,ortho '-magnesiations of aromatics and heterocycles using sBu(2)Mg in toluene

Hess, Andreas; Prohaska, Jan P.; Dörrich, Sabrina B.; Trauner, Florian; Lutter, Ferdinand H.; Lemaire, Sebastien; Wagschal, Simon; Karaghiosoff, Konstantin und Knochel, Paul (2021): Directed regioselective ortho,ortho '-magnesiations of aromatics and heterocycles using sBu(2)Mg in toluene. In: Chemical Science, Bd. 12, Nr. 24: S. 8424-8429

Abstract

Aryl azoles are ubiquitous as bioactive compounds and their regioselective functionalization is of utmost synthetic importance. Here, we report the development of a toluene-soluble dialkylmagnesium base sBu(2)Mg. This new reagent allows mild and regioselective ortho-magnesiations of various N-arylated pyrazoles and 1,2,3-triazoles as well as arenes bearing oxazoline, phosphorodiamidate or amide directing groups. The resulting diarylmagnesium reagents were further functionalized either by Pd-catalyzed arylation or by trapping reactions with a broad range of electrophiles (aldehydes, ketones, allylic halides, acyl chlorides, Weinreb amides, aryl halides, hydroxylamine benzoates, terminal alkynes). Furthermore, several double ortho,ortho '-magnesiations were realized in the case of aryl oxazolines, N-aryl pyrazoles as well as 2-aryl-2H-1,2,3-triazoles by simply repeating the magnesiation/electrophile trapping sequence allowing the preparation of valuable 1,2,3-functionalized arenes.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Chemie und Pharmazie > Department Chemie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• ISSN: 2041-6520
• Sprache: Englisch