Strauss MJ, Greaves ME, Kim ST, Teijaro CN, Schmidt MA, Scola PM, Buchwald SL. Room-Temperature Copper-Catalyzed Etherification of Aryl Bromides.
Angew Chem Int Ed Engl 2024;
63:e202400333. [PMID:
38359082 PMCID:
PMC11045308 DOI:
10.1002/anie.202400333]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 02/17/2024]
Abstract
We disclose the development of a Cu-catalyzed C-O coupling method utilizing a new N1,N2-diarylbenzene-1,2-diamine ligand, L8. Under optimized reaction conditions, structurally diverse aryl and heteroaryl bromides underwent efficient coupling with a variety of alcohols at room temperature using an L8-based catalyst. Notably, the L8-derived catalyst exhibited enhanced activity when compared to the L4-based system previously disclosed for C-N coupling, namely the ability to functionalize aryl bromides containing acidic functional groups. Mechanistic studies demonstrate that C-O coupling utilizing L8 ⋅ Cu involves rate-limiting alkoxide transmetallation, resulting in a mechanism of C-O bond formation that is distinct from previously described Pd-, Cu-, or Ni-based systems. This lower energy pathway leads to rapid C-O bond formation; a 7-fold increase relative to what is seen with other ligands. The results presented in this report overcome limitations in previously described C-O coupling methods and introduce a new ligand that we anticipate may be useful in other Cu-catalyzed C-heteroatom bond-forming reactions.
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