Accessing <i>para</i>-Alkylphenols via Iridium-Catalyzed Site-Specific Deoxygenation of Alcohols
Jing Wang, Tingting Wang, Hongguang Du, Ning Chen, Jiaxi Xu, Zhanhui Yang
Abstract
An iridium-catalyzed and phenol-directed deoxygenation of benzylic alcohols comes as an alternative access to 4-alkylphenols, featuring low catalyst loading ( S / C up to 20,000, TOF up to 12,400 h –1 ), high functionality compatibility, and excellent site-selectivity. The applications in late-stage modification of steroids and gram-scale total synthesis of a Gastrodia elata extract are highlighted. Mechanistically, the intermediacy of quinone methide controls the site-selectivity, and the formation of iridium hydride serves as the rate-limiting step.
Topics & Concepts
DeoxygenationChemistryIridiumSelectivityCatalysisPhenolHydridePhenolsCombinatorial chemistryOrganic chemistryHydrogenSynthetic Organic Chemistry MethodsAsymmetric Hydrogenation and CatalysisChemical Synthesis and Analysis