Pd-catalyzed Aerobic Cross-Dehydrogenative Coupling of Catechols with 2-Oxindoles and Benzofuranones: Reactivity Difference Between Monomer and Dimer.

Autor: Sugawara M; Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, Japan., Sawamura M; Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, Japan.; Tokyo Medical and Dental University, Tokyo, 113-8510, Japan., Akakabe M; Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, Japan.; Catalysis and Integrated Research Group RIKEN Center for Sustainable Resource Science., Ramadoss B; Catalysis and Integrated Research Group RIKEN Center for Sustainable Resource Science., Sohtome Y; Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, Japan.; Catalysis and Integrated Research Group RIKEN Center for Sustainable Resource Science., Sodeoka M; Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, Japan.; Catalysis and Integrated Research Group RIKEN Center for Sustainable Resource Science.; Tokyo Medical and Dental University, Tokyo, 113-8510, Japan.
Jazyk: angličtina
Zdroj: Chemistry, an Asian journal [Chem Asian J] 2022 Oct 17; Vol. 17 (20), pp. e202200807. Date of Electronic Publication: 2022 Sep 22.
DOI: 10.1002/asia.202200807
Abstrakt: Persistent radicals, which are generated from 2-oxindole or benzofuranone dimers, are useful tools for designing the radical-based cross-coupling reaction to provide molecules containing a quaternary carbon. The persistent radical is accessible from both the dimer and monomer; however, the reactivity difference between these substrates for the oxidative cross-coupling reaction is not fully understood, most likely because of the mechanistic complexity. Here, we present details of an aerobic cross-dehydrogenative coupling (CDC) reaction using various monomers and catechols. UV-Vis analysis and mechanistic control experiments showed that the monomer is less reactive than the dimer under aerobic conditions. Our Pd(II)-BINAP-μ-hydroxo complex significantly improved the reactivity of the monomers for the aerobic CDC reaction with catechols, yielding results comparable to those of the corresponding dimer. The procedure, which enables the generation of the persistent radical in situ, is particularly useful when employing the monomer that is not readily converted to the corresponding dimer.
(© 2022 The Authors. Chemistry - An Asian Journal published by Wiley-VCH GmbH.)
Databáze: MEDLINE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje