Scalable Cu(II)-mediated intramolecular dehydrogenative phenol-phenol coupling: Concise synthesis of enantiopure axially chiral homo- and hetero-diphenols

Publication date: Available online 11 February 2020Source: Chinese Chemical LettersAuthor(s): Yuefei Gu, Tianyang Wang, Ming Gao, Zhu-Jun YaoAbstractAn intramolecular dehydrogenative homo- and hetero-coupling of phenols has been successfully developed for quick preparation of enantiopure axial diphenols under mild Cu(II)-mediated conditions, using ((4S,5S)-2,2-dimethyl-1,3-dioxolane-4,5-diyl)dimethanol as the chiral auxiliary. The commercially available (R)-α-methylbenzylamine was identified as the best amine ligand for Cu(II) in the reactions. A variety of homo/hetero bis-dihydroxylbenzoate substrates were examined, affording the corresponding axially chiral diphenols with satisfactory to excellent diastereomeric ratios, and a representative scalable preparation was also attempted. A formal synthesis of natural product (+)-deoxyschizandrin has been achieved in this work using one axially chiral diphenol as the synthetic intermediate.Graphical AbstractA series of intramolecular homo/hetero phenol-pheno couplings have been achieved with Cu(II)-mediated oxidative conditions, delivering the corresponding enantiopure axially chiral diphenols.

Source: Chinese Chemical Letters - February 12, 2020 Category: Chemistry Source Type: research