Synthesis of Highly Functionalized Diaryl Ethers by Copper‐Mediated O‐Arylation of Phenols using Trivalent Arylbismuth Reagents

Abstract

Highly functionalized diaryl ethers were prepared by copper(II) acetate mediated O-arylation reaction of phenols using trivalent organobismuthanes. The reaction is performed under simple conditions and tolerates a wide diversity of functional groups on the phenol and on the organobismuth reagent. Substoichiometric amounts of catalyst can be used by performing the reaction under an oxygen atmosphere. The N-arylation of pyridones is also reported.

Synthesis of aryl cyclopropyl sulfides through copper-promoted S-cyclopropylation of thiophenols using cyclopropylboronic acid

“…Due to the borderline behavior of bismuth as a metal and a ligand, organobismuth species have been used as reagents and catalysts in a wide range of reactions. We reported a portfolio of methods for the construction of C–C [26–29], C–N [30] and C–O bonds [31–33] using triaryl- and trialkylbismuthines [34]. We also disclosed for the first time in 2007 the synthesis of tricyclopropylbismuth ( 24 ) and its use in N-cyclopropylation [35], palladium-catalyzed cross coupling [36] and carbonylative cross-coupling reactions [37].…”

Copper‐Promoted O‐Arylation of the Phenol Side Chain of Tyrosine Using Triarylbismuthines

“…Over the past decade, our group has reported a repertoire of metal‐catalyzed reactions that involve trivalent organobismuth reagents and that result in the transfer of alkyl, cyclopropyl and aryl/heteroaryl groups onto various scaffolds. In 2014, we disclosed a highly efficient protocol for the O‐arylation of phenols using triarylbismuth reagents and hypothesized that the reaction proceeds through a copper(III) species where the metal center is simultaneously bound to the phenoxide and the aryl group (Scheme d ) . In contrast to Barton's O‐phenylation procedure, this reaction operates directly from triarylbismuthines, a class of reagents which can be easily prepared by the addition of Grignard species to bismuth trichloride and where the functional groups can be modified directly on the bismuth species …”

“…Using our conditions for the O‐arylation of phenols, N ‐Boc tyrosine methyl ester 1a reacted to give the desired product 3a in 35 % yield (Table , entry 1). Systematic optimization of the reaction parameters (entries 2 to 4) indicated that a quantitative yield could be obtained by using pyridine in the presence of 0.3 equivalents of copper acetate under oxygen at 50 °C for 16 hours in non‐anhydrous dichloromethane (entry 5).…”

Advances in Carbon–Element Bond Construction under Chan–Lam Cross-Coupling Conditions: A Second Decade

“…In 2014, Gagnon and co-workers reported Cu(OAc) 2 -mediated O-arylation reaction of phenols and trivalent organobismuthanes to give highly functionalized diaryl ethers (Scheme 100). 84 Various phenols bearing different functional groups and a variety of organobismuth reagents reacted under these simple reaction conditions. By using an oxygen atmosphere, the amount of catalyst used in the reaction can be significantly minimized (conditions B).…”