Nitrogen Atom Transfer Catalysis by Metallonitrene C−H Insertion: Photocatalytic Amidation of Aldehydes. (14th January 2022)

• Record Type: Journal Article
• Authors: Schmidt‐Räntsch, Till; Verplancke, Hendrik; Lienert, Jonas N.; Demeshko, Serhiy; Otte, Matthias; Van Trieste, Gerard P.; Reid, Kaleb A.; Reibenspies, Joseph H.; Powers, David C.; Holthausen, Max C.; Schneider, Sven
• Is Part Of: Angewandte Chemie. Volume 134:Number 9(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-14
• Subjects: Amides -- C−H Activation -- Nitrenes -- Palladium -- Photocatalysis; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202115626
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: C−H amination and amidation by catalytic nitrene transfer are well‐established and typically proceed via electrophilic attack of nitrenoid intermediates. In contrast, the insertion of (formal) terminal nitride ligands into C−H bonds is much less developed and catalytic nitrogen atom transfer remains unknown. We here report the synthesis of a formal terminal nitride complex of palladium. Photocrystallographic, magnetic, and computational characterization support the assignment as an authentic metallonitrene (Pd−N) with a diradical nitrogen ligand that is singly bonded to Pd II . Despite the subvalent nitrene character, selective C−H insertion with aldehydes follows nucleophilic selectivity. Transamidation of the benzamide product is enabled by reaction with N3 SiMe3 . Based on these results, a photocatalytic protocol for aldehyde C−H trimethylsilylamidation was developed that exhibits inverted, nucleophilic selectivity as compared to typical nitrene transfer catalysis. This first example of catalytic C−H nitrogen atom transfer offers facile access to primary amides after deprotection. Abstract : Photocatalytic nitrogen atom transfer into aldehyde C−H bonds is reported. A palladium(II) metallonitrene species with nitrogen‐centered biradical character was identified as the key intermediate and was photocrystallographically, magnetically and computationally characterized. The nucleophilic metallonitrene C−H insertion step results in inverted selectivity for the net nitrene transfer catalysis.