Triazole-Assisted Ruthenium-Catalyzed CH Arylation of Aromatic Amides

• Published in: Chemistry : a European journal Vol. 20; no. 31; pp. 9739 - 9743
• Main Authors: Al Mamari, Hamad H., Diers, Emelyne, Ackermann, Lutz
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 28.07.2014; WILEY‐VCH Verlag; Wiley
• Subjects: Accessibility; Activation; Alkenes; Amides; Aromatic compounds; aryl halides; catalysis; Chemistry; Chemistry, Multidisciplinary; Cleavage; CH activation; Modular; Physical Sciences; ruthenium; Science & Technology; Strategy; triazoles; DIRECTING GROUP; C(SP)-H BONDS; amides; ACTIVATION; DIRECT FUNCTIONALIZATION; CLICK CHEMISTRY; ALKYLATION; triazoles; catalysis; ruthenium; UNACTIVATED C(SP)-H BONDS; ACID-DERIVATIVES; aryl halides; C-H activation; INTRAMOLECULAR AMINATION; ARYL CHLORIDES; CH activation
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201403019

Site‐selective ruthenium(II)‐catalyzed direct arylation of amides was achieved through CH cleavages with modular auxiliaries, derived from easily accessible 1,2,3‐triazoles. The triazolyldimethylmethyl (TAM) bidentate directing group was prepared in a highly modular fashion through copper(I)‐catalyzed 1,3‐dipolar cycloaddition and allowed for ruthenium‐catalyzed CH arylations on arenes and heteroarenes, as well as alkenes, by using easy‐to‐handle aryl bromides as the arylating reagents. The triazole‐assisted CH activation strategy was found to be widely applicable, to occur under mild reaction conditions, and the catalytic system was tolerant of important electrophilic functionalities. Notably, the flexible triazole‐based auxiliary proved to be a more potent directing group for the optimized ruthenium(II)‐catalyzed direct arylations, compared with pyridyl‐substituted amides or substrates derived from 8‐aminoquinoline. Assisting activation: Ruthenium(II)‐catalyzed CH arylations of (hetero)arenes and alkenes have been achieved with aryl halides through removable bidentate auxiliaries derived from modular 1,2,3‐triazoles (see scheme; TAM=triazolyldimethylmethyl).