38674-44-1Relevant 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.
Preparation, molecular structure and reactivity of mono- and di-nuclear sulfonato rhodium(I) complexes
Werner, Helmut,Bosch, Marco,Schneider, Michael E.,Hahn, Christine,Kukla, Frank,Manger, Matthias,Windmueller, Bettina,Weberndoerfer, Birgit,Laubender, Matthias
, p. 3549 - 3558 (2007/10/03)
The reaction of [Rh(η3-C3H5)(PPri 3)2] 1 or [Rh(η3-CH2Ph)(PPri3) 2] 2 with an equimolar amount of RSO3H (R = Me, p-tolyl, CF3, F, Camph) led to the formation of the monomeric sulfonatorhodium(I) complexes [Rh{η2-O2S(O)R}(PPri3) 2] 3-7 in excellent yield. An alternative route for the preparation of 4 (R = p-tolyl) and 5 (R = CF3) is based on the reaction of PPri3 with the dinuclear compounds [{Rh(C8H14)2[μ-O2S(O)R]} 2], which were obtained either from [{Rh(C8H14)2(μ-Cl)}2] 8 or [{Rh(C8H14)2(μ-OH)}2] 9 as starting materials. Compounds 3-7 react smoothly with hydrogen by oxidative addition to give the dihydridorhodium(III) complexes [RhH2{η2-O2S(O)R}(PPri 3)2]. Moreover, on treatment of 3-6 with CO and C2H4 the chelating bond of the sulfonate ligand is partially opened and the carbonyl and ethene complexes trans-[Rh{η1-OS(O)2R}(L)(PPri 3)2] (L = CO or C2H4) are formed. The bis(stibine)-rhodium(I) derivative trans-[Rh{η1-OS(O)2CF3}(C2H 4)(SbPri3)2] was obtained from [{Rh(C2H4)2[μ-O2S(O)CF 3]}2] and SbPri3. Reaction of the compounds [Rh{η2-O2S(O)CF3}(olefin)(PPri 3)] (olefin = C8H14 or C2H4) with benzene led to the displacement of the sulfonate ligand and to the formation of the half-sandwich-type complexes [Rh{η6-C6H6)-(olefin)(PPri 3)][CF3SO3] containing a rather labile benzene-rhodium bond. The preparation of the vinylidene complex trans-[Rh{η1-OS(O)C6H 4Me-p}(=C=CHPh)(PPri3)2] is also described and the crystal and molecular structures of three compounds have been determined. The four-co-ordinate sulfonato complexes 3-6 are active catalysts in the C-C coupling reaction of ethene and diphenyldiazomethane. Besides the three isomeric 1:1 adducts of C2H4 and CPh2, quite unexpectedly also the 2:1 adduct 3,3-diphenylpent-1-ene is formed.
