- N -Arylation of (hetero)arylamines using aryl sulfamates and carbamates via C-O bond activation enabled by a reusable and durable nickel(0) catalyst
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An effective and general aryl amination protocol has been developed using a magnetically recoverable Ni(0) based nanocatalyst. This new stable catalyst was prepared on Fe3O4@SiO2 modified by EDTA and investigated by FT-IR, EDX, TEM, XRD, DLS, FE-SEM, XPS, NMR, TGA, VSM, ICP and elemental analysis techniques. The reaction proceeded via carbon-oxygen bond cleavage of (hetero)aryl carbamates and sulfamates under simple and mild conditions without the use of any external ligands. This method demonstrated functional group tolerance in the N-arylation of various nitrogen-containing compounds as well as aliphatic amines, anilines, pyrroles, pyrazoles, imidazoles, indoles, and indazoles with good to excellent yields. Furthermore, the catalyst could be easily recovered by using an external magnetic field and directly reused at least six times without notable reduction in its activity. This journal is
- Dindarloo Inaloo, Iman,Majnooni, Sahar,Eslahi, Hassan,Esmaeilpour, Mohsen
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p. 13266 - 13278
(2020/10/07)
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- Pd-catalyzed Suzuki-Miyaura cross-coupling reactions between sulfamates and potassium Boc-protected aminomethyltrifluoroborates
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Sulfamates were studied as the electrophilic partners in the palladium-catalyzed Suzuki-Miyaura cross-coupling reaction with potassium Boc-protected primary and secondary aminomethyltrifluoroborates. A broad range of substrates was successfully coupled to provide the desired products. Complex molecules containing a new carbon-carbon bond and an aminomethyl moiety could be prepared through this developed method.
- Molander, Gary A.,Shin, Inji
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supporting information
p. 2534 - 2537
(2013/06/27)
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- AMINOLYSIS AND HYDROLYSIS OF SULPHAMATE ESTERS: SUBSTANTIAL N=S BONDING IN THE TRANSITION STATE LEADING TO N=SULFONYLAMINES
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The aminolysis and hydrolysis of several sulphamate esters, RNHSO2ONp (R = PhCH2, Ph, 4-MeC6H4, 3-MeC6H4, 4-FC6H4, 4-ClC6H4, 3-ClC6H4, H; Np = 4-NO2C6H4) were been studied in 50 percent (v/v) aqueous acetonitrile at various temperatures.Reaction of the esters with an amine (R1NH2) gives -ONp and both sulphamide, (RNHSO2NHR1) and sulphamate (RNHSO2O-R1NH3+) products.First-order rates were determined by the appearance of -ONp and sometimes also by the disappearance of ester.The reaction was found to be independent of amine type and concentration and at the high pHs that obtain the substrate esters are fully ionized.A Hammett ρacyl of -1.8 was obtained for the decomposition of the sulphamate anions and this is consistent with substantial N=S bonding in the transition state leading to N-sulphonylamine, RN=SO2.This intermediate then partitions very rapidly, reacting with R1NH2 and H2O respectively. ΔH*, ΔS* and a deuterium solvent isotope effect were determined and were also interpreted in favour of the proposed mechanism.The dimethyl sulphamate ester (Me2NSO2ONp) does not react under the conditions used.
- Spillane, William J.,Hogan, Geraldine,McGrath, Paul
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p. 610 - 616
(2007/10/02)
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- Versatile Synthesis of Sulphamate Esters by Phase-transfer Methods
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The syntheses of sulphamate esters of the general types R1R2NSO3R3, RNHSO3R3, and H2NSO3R3, where R3 may be aliphatic or aromatic, have been achieved in good yield by reaction of the appropriate sulphamoyl chlorides with alcohols and phenols under mild phase-transfer conditions.The present methods have led to generally higher yields, and to shorter reaction times and lower reaction temperatures than were hitherto found necessary.The prior preparation of the alkoxide has also been obviated.Some esters have been rearranged to the isomeric betaines.
- Spillane, William J.,Taheny, Anne P.,Kearns, M. Mary
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p. 677 - 680
(2007/10/02)
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- Betylates. 1. Synthesis and reactions of an isolable betylate, N,N-dimethyl-N-(phenoxysulfonyl)methanaminium fluorosulfate
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Phenyl betylate fluorosulfate (2), the first example of a "betylate" (trialkylammoniosulfate ester), has been prepared by methylation of phenyl N,N-dimethylsulfamate with methyl fluorosulfate.Nucleophiles react with 2 either by attack on the sulfur or methyl carbon atoms, but with no sign of any products derived from benzyne or the phenyl cation.A synthesis of enol N,N-dimethylsulfamates has been devised using a reagent, Me2NSO2N(1+)Me3 FSO3(1-), prepared from tetramethylsulfamide and methyl fluorosulfate, but no satisfactory method was found for converting the sulfamic ester to the betylate.Evidence is presented that phenyl chlorosulfate reacts with trimethylamine to give the phenylbetylate which then undergoes further reaction.
- King, James Frederick,Lee, Teresa Mee-Ling
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p. 356 - 361
(2007/10/02)
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