Direct Regioselective Dehydrogenation of α‐Substituted Cyclic Ketones
Sebastian Schwengers, Gabriela G. Gerosa, Tynchtyk Amatov, Naoki Yasukawa, Sebastian Brunen, Markus Leutzsch, Benjamin Mitschke, Grigory A. Shevchenko, Benjamin List
Abstract
We disclose a highly regioselective, catalytic one-step dehydrogenation of α-substituted cyclic ketones in the presence of 2,3-dichlorobenzo-5,6-dicyano-1,4-benzoquinone (DDQ). The high regioselectivity originates from a phosphoric acid-catalyzed enolization, selectively affording the thermodynamically preferred enol, followed by the subsequent oxidation event. Our method provides reliable access to several α-aryl and α-alkyl substituted α,β-unsaturated ketones.
Topics & Concepts
RegioselectivityDehydrogenationChemistryEnolAlkylKeto–enol tautomerismCatalysisArylPhosphoric acidKetoneOrganic chemistryMedicinal chemistryAsymmetric Synthesis and CatalysisCatalytic C–H Functionalization MethodsSynthesis and Catalytic Reactions