158660-01-6Relevant articles and documents
Tuning Triplet Energy Transfer of Hydroxamates as the Nitrene Precursor for Intramolecular C(sp3)-H Amidation
Chang, Sukbok,Jung, Hoimin,Keum, Hyeyun,Kweon, Jeonguk
supporting information, p. 5811 - 5818 (2020/04/10)
Reported herein is the design of a photosensitization strategy to generate triplet nitrenes and its applicability for the intramolecular C-H amidation reactions. Substrate optimization by tuning physical organic parameters according to the proposed energy transfer pathway led us to identify hydroxamates as a convenient nitrene precursor. While more classical nitrene sources, representatively organic azides, were ineffective under the current photosensitization conditions, hydroxamates, which are readily available from alcohols or carboxylic acids, are highly efficient in accessing synthetically valuable 2-oxazolidinones and γ-lactams by visible light. Mechanism studies supported our working hypothesis that the energy transfer path is mainly operative.
Conical intersection control of heterocyclic photochemical bond scission
Zimmerman, Howard E.,Mitkin, Oleg D.
, p. 12743 - 12749 (2008/02/08)
The photochemistry of the heterocycle 5,6-dihydro-1-methyl-5,5- diphenylpyridin-2(1H)-one (compound 1 in the text) leads to two competitive reactions (the reactions are depicted in the Introduction to the article). These arise from fission of bond a, betw
Reaction of Superoxide with Aci-Reductones
Frimer, Aryeh A.,Marks, Vered,Gilinsky-Sharon, Pessia,Aljadeff, Gladis,Gottlieb, Hugo E.
, p. 4510 - 4520 (2007/10/02)
Three reductones, 2,3-dihydroxy-4,4-diphenyl-2,5-cyclohexadien-1-one (11), 3,4-dihydroxycoumarin (35), and 3,4-dihydroxyspiroundecan-3-en-4-one (64), were prepared and subsequently reacted with superoxide anion radical (O2(.-), generated from KO2 and 18-crown-6-polyether.The reactions were carried out in aprotic media and quenched with methyl iodide which facilitates the trapping of the various oxyanions formed.While a plethora of products were formed in each case undeca-1,4-dien-3-one (66), 2-hydroxyspirodec-1-en-3-one (70), dimethyl 1,1-cyclohexanediacetate (73), and dimethyl α-keto-1-cyclohexane-1-propionate) (75) from 64> an overall analysis of the product distribution indicates that the basic elements of the reaction sequence are the same.The first step involves facile deprotonation and the concomitant generation of the reductone monoanion, a process which lends support to the suggestion of Afanas'ev and co-workers (Afanas'ev, I.B., Grabovietskii, V.V.; Kuprianova, N.S. J.Chem.Soc.Perkin Trans. 2 1987, 281-285).Oxidation of this monoanion yields the corresponding triketone.Of the various options available to this polyketone, superoxide attack at the most electrophilic central carbonyl followed by oxidative cleavage and/or benzylic acid rearrangement are clearly the most prominent.These are followed by a variety of base catalyzed autoxidative processes which are highly dependent on the nature of the substrate.
