Nickel-Catalyzed Chelation-Assisted Transformations Involving Ortho C–H Bond Activation: Regioselective Oxidative Cycloaddition of Aromatic Amides to Alkynes

Abstract

Although the pioneering example of ortho metalation involving cleavage of C-H bonds was achieved using a nickel complex (Kleiman, J. P.; Dubeck, M. J. Am. Chem. Soc. 1963, 85, 1544), no examples of catalysis using nickel complexes have been reported. In this work, the Ni-catalyzed transformation of ortho C-H bonds utilizing chelation assistance, such as oxidative cycloaddition of aromatic amides with alkynes, has been achieved.

Nickel Catalysts/N,N′-Bidentate Directing Groups: An Excellent Partnership in Directed C–H Activation Reactions

“…In 2011, we reported on the first example of Ni-catalyzed chelation-assisted functionalization of CH bonds using an N,N¤-bidentate directing group (Scheme 1). 15 The reaction involves the oxidative cycloaddition of aromatic amides to internal alkynes using a 2-pyridinylmethylamine moiety as the directing group for the synthesis of isoquinolones. The catalyst was generated in situ by reacting [Ni(cod) 2 ] and PPh 3 in toluene at 160°C.…”

Nickel-Catalyzed C–H Bond Functionalization Utilizing an N,N′-Bidentate Directing Group

“…In 2011, Chatani and coworkers reported on the Ni(0)-catalyzed oxidative cycloaddition of aromatic amides 1 to internal alkynes for the synthesis of isoquinolone derivatives 2 (Scheme 4) [22]. A similar transformation was previously reported Scheme 2 Cyclometalation using NiBr 2 Scheme 3 Imidazolium C-H/alkene coupling reaction Fig.…”

Katalytische Funktionalisierung von C(sp2)‐H‐ und C(sp3)‐H‐Bindungen unter Verwendung von zweizähnigen dirigierenden Gruppen

“…Erst Chatani et al berichteten über die erste nickelkatalysierte Umwandlung von ortho-C-H-Bindungen unter Verwendung einer dirigierenden Gruppe. [53] Eine zweizähnige dirigierende 2-Prydinylmethylamingruppe bewirkte bei hoher Temperatur die Ni 0 -katalysierte ortho-C-H-Addition von Amiden an Substrate mit einem internen Alkin, gefolgt von der Insertion in die N-H-Bindung des Amids unter Bildung cyclischer Isochinolinderivate (Schema 38). Die Reaktion von m-substituierten Amiden führte zur Funktionalisierung an der sterisch weniger gehinderten C-H-Bindung.…”