CpRh()-catalyzed regioselective cyclization of aromatic amides with allenes

• Published in: Chemical communications (Cambridge, England) Vol. 6; no. 5; pp. 598 - 61
• Main Authors: Liu, Jing, Liu, Deng-Yin, Yang, Qian, Zeng, Yao-Fu, Wang, Xiao-Li, Wang, Peng-Fei, Ruan, Yu-Jun, Wen, Miao-Miao, Zhang, Shang-Shi, Du, Li-da, Liu, Xu-Ge
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 11.01.2024; Royal Society of Chemistry
• Subjects: Amides; Benzamide; Chemistry; Chemistry, Multidisciplinary; Physical Sciences; Regioselectivity; Science & Technology; Substrates; ANNULATIONS; MIGRATION; MECHANISM; C-H ACTIVATION; ALLYLATION
• ISSN: 1359-7345; 1364-548X
• DOI: 10.1039/d3cc05342c

A new Cp*Rh( iii )-catalyzed regioselective cyclization reaction of aromatic amides with allenes is reported. The use of allenyl derivatives bearing a directing-group assistant as a reaction promoter was the key to the success of this protocol. In this catalytic system, N -(pivaloyloxy)benzamide substrates react with allenes via Rh-σ-alkenyl intermediates, while N -(pivaloyloxy) indol substrates react via Rh-π-allyl intermediates. These reactions were characterized by mild reaction conditions, a broad substrate scope, and high functional-group compatibility to yield several high-value isoquinolinone and pyrimido[1,6- a ]indol-1(2 H )-one skeleton-containing compounds. The synthetic applications and primary mechanisms were also investigated. A mild reaction condition is employed for the Cp*Rh( iii )-catalyzed regioselective annulation of aromatic amides with allenes, enabling the preparation of isoquinolin-1(2 H )-ones and pyrimido[1,6- a ]indol-1(2 H )-one.