Enantioselective Biomimetic Cyclization of Isoprenoids Using Lewis Acid-Assisted Chiral Brønsted Acids: Abnormal Claisen Rearrangements and Successive Cyclizations
have been achieved by several groups; however, no general “biomimetic” method has yet been reported. In this paper we describe the biomimeticcyclization of simple isoprenoids to polycyclic isoprenoids using Lewis acid-assisted chiral Bronsted acids, “chiral LBAs”. This is the first example of a proton-induced enantioselective ene cyclization in synthetic chemistry. Geranyl phenyl ethers, o-geranylphenols
Metal-Free C–O Bond Functionalization: Catalytic Intramolecular and Intermolecular Benzylation of Arenes
作者:Luis Bering、Kirujan Jeyakumar、Andrey P. Antonchick
DOI:10.1021/acs.orglett.8b01495
日期:2018.7.6
conditions enabled a catalytic and metal-free Friedel–Craftsalkylation reaction with benzylic alcohols, producing water as the stoichiometric byproduct. A comprehensive scope (>50 examples) for both approaches and application in drug synthesis were demonstrated. Mechanistic studies suggest a Lewis acid-based mechanism for the metal-free Friedel–Crafts reaction.