Synthesis of Seven- and Eight-Membered Rings by a Brønsted Acid Catalyzed Cationic Carbocyclization of Biphenyl Embedded Enynes
Jaime Tostado, Ana Milián, Juan J. Vaquero, Manuel A. Fernández‐Rodríguez
Abstract
High Resolution Image Download MS PowerPoint Slide A Brønsted acid catalyzed cyclization of o -alkenyl- o′ -alkynylbiaryls for the synthesis of biologically relevant dibenzo-fused medium-sized rings has been developed. The outcome of the cyclization is determined by the nature of the substituent at the alkyne, with arenes favoring seven-membered rings and alkyl substituents producing eight-membered rings. These reactions proceed via a vinyl cation, which is captured by water and, notably, by C-nucleophiles, such as electron-rich (hetero)arenes.
Topics & Concepts
ChemistryCationic polymerizationNucleophileSubstituentAlkyneBiphenylCatalysisBrønsted–Lowry acid–base theoryAlkylRing (chemistry)ElectrophileMedicinal chemistryStereochemistryOrganic chemistryCatalytic Alkyne ReactionsCatalytic C–H Functionalization MethodsCatalytic Cross-Coupling Reactions