Three Groups Good, Four Groups Bad? Atropisomerism in ortho‐Substituted Diaryl Ethers

Abstract

Bring on the substitute: Even outside of macrocyclic structures, such as vancomycin, appropriate substitution can give rise to atropisomerism in diaryl ethers. Stereochemical stability about the ArOAr axis at room temperature or above is possible when neither of the rings is symmetrically substituted and when at least one ring carries an ortho tert‐butyl group or equivalent.

Synthesis of six-membered silacycles by borane-catalyzed double sila-Friedel–Crafts reaction

“…Six-membered silacyclic compounds, such as phenoxasilin and phenothiasilin derivatives, are attractive compounds for applications as organic electronic materials [1][2][3][4], ligands [5][6][7][8][9][10], and reagents [11][12][13][14]. Therefore, the development of new methods to construct silacyclic skeletons is highly desirable.…”

Cu-Catalyzed Arylation of Phenols: Synthesis of Sterically Hindered and Heteroaryl Diaryl Ethers

“…7-9 This motif also appears in biologically active natural products, notably in the mammalian hormone thyroxine 10 and the vancomycin family of antibiotics. 11 There has been recent interest in the synthesis of atropisomeric diaryl ethers 12,13 as these may have application as molecular gears. 14 …”

Biocatalytic Desymmetrization of an Atropisomer with both an Enantioselective Oxidase and Ketoreductases

“…The enzymes we employed for these transformations were 1) a variant of galactose oxidase (GOase) which had been previously evolved to accept chiral benzylic alcohols as substrates with high enantioselectivity (1!2) [7] and 2) a family of ketoreductases that are known to possess good activity and enantioselectivity for the asymmetric reduction of benzylic ketones (3!2). [8] Atropisomeric diaryl ethers [9] form part of the structure of vancomycin [10] and are promising scaffolds for the construction for new chiral ligands. [11] Dialdehyde 3 and diol 1 were made by our published route.…”

“…[11] Dialdehyde 3 and diol 1 were made by our published route. [9] In an initial screen, we attempted enantioselective acetylation by incubating diol 1 with Candida antarctica lipase B and vinyl acetate. Slow acylation of 1 was observed with approximately 50 % conversion after 24 h to the monoacetate 4 and modest enantioselectivity (60 % ee).…”

“…Atropisomeric diaryl ethers [9] form part of the structure of vancomycin [10] and are promising scaffolds for the construction for new chiral ligands. [11] Dialdehyde 3 and diol 1 were made by our published route.…”