126314-00-9Relevant articles and documents
Cerium-catalyzed α-hydroxylation reactions of α-cyclopropyl β-dicarbonyl compounds with molecular oxygen
Christoffers, Jens,Kauf, Thomas,Werner, Thomas,Roessle, Michael
, p. 2601 - 2608 (2007/10/03)
Three α-cyclopropyl β-dicarbonyl compounds have been used as probes for α-radicals as electrophilic reaction intermediates in a cerium-catalyzed α-hydroxylation reaction with molecular oxygen. Since the cyclopropyl group did not ring-open to products with a butenyl moiety, but was retained in the products, a localized unpaired electron at the α position can be excluded during the course of the reaction. The α-cyclopropyl- substituted substrates were prepared by aldol or Claisen reactions. Other substrates with α-methyl, α-isopropyl, and α-tert-butyl substituents were prepared and converted under the α-hydroxylation conditions in order to estimate steric influences on the yield of the reaction. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
REACTIONS RELATED TO COENZYME B12 DEPENDENT REARRANGEMENTS: METAL MEDIATED FREE RADICAL ACYL MIGRATIONS IN METHYL AND CYCLOPROPYL SUBSTITUTED MODELS
Best, Wayne M.,Widdowson, David A.
, p. 5943 - 5954 (2007/10/02)
Free radicals generated from the methylmalonylcoenzyme A mutase model substrates (3) and (4) by chromium(II) reduction, or by pyrolysis of the analogous cobaloximes, underwent -migration only in the acyl series (R=Ph, Me) and not the critical ester series (R=OEt, SBu).The mechanism of the migration was implied by incorporation into (4) of the cyclopropyl ring, the opening of which demonstrated the free radical nature of rearranged intermediate.
