Copper‐Catalyzed Electrophilic Etherification of Arylboronic Esters with Isoxazolidines. Issue 12 (25th May 2020)

• Record Type: Journal Article
• Authors: Katahara, Seiya; Takahashi, Tenga; Nomura, Kengo; Uchiyama, Masanobu; Sato, Takaaki; Chida, Noritaka
• Is Part Of: Chemistry, an Asian journal. Volume 15:Issue 12(2020)
• Page Start: 1869
• Page End: 1872
• Publication Date: 2020-05-25
• Subjects: aryl ether -- chemoselectivity -- copper catalyst -- electrophilic reaction -- isoxazolidine; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.202000270
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: A copper‐catalyzed electrophilic etherification of arylboronic esters is reported. Isoxazolidines are utilized as easily available and stable [RO] + surrogates to give 1, 3‐amino aryl ethers. The O ‐selective arylation of isoxazolidines takes place without causing competitive N ‐arylation. In contrast to previously reported anionic conditions, our copper‐catalyzed conditions are mild enough to achieve high functional group tolerance. Preliminary mechanistic studies and DFT calculations support that the reaction proceeds via a transmetalation/oxidative addition pathway, followed by a Lewis acid‐promoted reductive elimination to induce the crucial O ‐selectivity. Abstract : A copper‐catalyzed electrophilic etherification of arylboronic esters with isoxazolidines has been reported. The salient features of our method are 1) highly functionalized and stable isoxazolidines as electrophilic oxygen sources, 2) unprecedented O ‐selective arylation of isoxazolidines associated with N−O bond cleavage, and 3) high functional group tolerance compared with anionic conditions.