Ruthenium(IV) porphyrin catalyzed highly selective oxidation of internal alkenes into ketones with Cl2pyNO as terminal oxidant
摘要:
A new method for the conversion of internal alkenes into ketones without cleavage of C=C bond by using dichlororuthenium(IV) meso-tetrakis(2,6-dichlorophenyl)porphyrin [Ru-IV(TDCPP)Cl-2] as catalyst and 2,6-dichloropyridine N-oxide(Cl(2)pyNO) as oxidant is developed. (C) 2014 Elsevier Ltd. All rights reserved.
Abstract: We describe a highly stereoconvergent radical epoxide allylation towards diastereomerically and enantiomerically enriched α‐quaternary alcohols in two steps from olefins. Our approach combines the stereospecifity and enantioselectivity of the Shi epoxidation with the unprecedented Ti(III)‐promoted intramolecular radical group transfer allylation of epoxides. A directional isomerization step via configurationally labile radical intermediates enables the selective preparation of all carbon quaternary stereocenters in a unique fashion.