Chromium(II)-Catalyzed Diastereoselective and Chemoselective Csp(2)-Csp(3) Cross-Couplings Using Organomagnesium Reagents

Li, Jie; Ren, Qianyi; Cheng, Xinyi; Karaghiosoff, Konstantin und Knochel, Paul (2019): Chromium(II)-Catalyzed Diastereoselective and Chemoselective Csp(2)-Csp(3) Cross-Couplings Using Organomagnesium Reagents. In: Journal of the American Chemical Society, Bd. 141, Nr. 45: S. 18127-18135

Abstract

A simple protocol for performing chromium catalyzed highly diastereoselective alkylations of arylmagnesium halides with cyclohexyl iodides at ambient temperature has been developed. Furthermore, this ligand-free CrCl2 enables efficient electrophilic alkenylations of primary, secondary, and tetiary alkylmagnesium halides with readily available alkenyl acetates. Moreover, this chemoselective C-C coupling reaction with stereodefined alkenyl acetates proceeds in a stereoretentive fashion. A wide range of functional groups on alkyl iodides and alkenyl acetates are well tolerated, thus furnishing functionalized Csp(2)-Csp(3) coupling products in good yields and high diastereoselectivity. Detailed mechanistic studies suggest that the in situ generated low-valent chromium(I) species might be the active catalyst for these Csp(2)-Csp(3) cross-couplings.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Chemie und Pharmazie > Department Chemie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• ISSN: 0002-7863
• Sprache: Englisch