1623-51-4Relevant articles and documents
Copper-catalyzed oxidative benzylic C(sp3)-H amination: Direct synthesis of benzylic carbamates
Liu, Shuai,Achou, Rapha?l,Boulanger, Coline,Pawar, Govind,Kumar, Nivesh,Lusseau, Jonathan,Robert, Frédéric,Landais, Yannick
supporting information, p. 13013 - 13016 (2020/11/05)
A new efficient strategy to access benzylic carbamates through C-H activation is reported. The use of a catalytic amount of a Cu(i)/diimine ligand in combination with NFSI ((PhSO2)2NF) or F-TEDA-PF6 as oxidants and H2NCO2R as an amine source directly leads to the C-N bond formation at the benzylic position. The mild reaction conditions and the broad substrate scope make this transformation a useful method for the late-stage incorporation of a ubiquitous carbamate fragment onto hydrocarbons. This journal is
BMIm HCO3: an ionic liquid with carboxylating properties. Synthesis of carbamate esters from amines
Di Nicola,Arcadi,Rossi
supporting information, p. 9895 - 9898 (2016/12/07)
1-Butyl-3-methylimidazolium hydrogen carbonate (BMIm HCO3) was used as an ionic liquid with carboxylating properties able to convert, in the presence of an alkyl halide, amines into the corresponding carbamate esters. Moderate to good yields of
Amberlyst-15 in ionic liquid: An efficient and recyclable reagent for nucleophilic substitution of alcohols and hydroamination of alkenes
Qureshi, Ziyauddin S.,Deshmukh, Krishna M.,Tambade, Pawan J.,Dhake, Kishor P.,Bhanage, Bhalchandra M.
experimental part, p. 6233 - 6238 (2010/12/25)
The nucleophilic substitution reaction of secondary alcohols and hydroamination of alkenes with amides, sulfonamides, carbamates, and amines using Amberlyst-15 immobilized in [Bmim][BF4] (1-butyl-3- methylimidazolium tetrafluoroborate) ionic liquid as an efficient recyclable reagent is described. The solvent effect is prominent in the reaction, and the desired substitution products are obtained in good to excellent yield. The protocol is advantageous due to the ease of handling of the reagents, the simple work-up procedure, and the environmentally benign conditions that allow effective recyclability. A facile protocol involving Amberlyst-15 in the ionic liquid [Bmim][BF4] (= 1-butyl-3-methylimidazolium tetrafluoroborate) has been developed for nucleophilic substitution of alcohols and hydroamination of alkenes.
Synthesis of carbamates from diethoxycarbonyl hydrazine derivatives by E1cB eliminative cleavage of the N-N′-bond rather than reduction
Magnus, Philip,Garizi, Negar,Seibert, Kimberly A.,Ornholt, Alexandra
supporting information; experimental part, p. 5646 - 5648 (2010/02/28)
[Chemical Equation Presented] Treatment of diethoxycarbonyl hydrazine derivatives with methyl bromoacetate/Cs2CO3/MeCN at 50°C followed by heating to 80°C resulted in N-N′ bond cleavage to the corresponding carbamates.
CATALYTIC ASYMMETRIC SYNTHESIS OF PRIMARY AMINES VIA BORANE REDUCTION OF OXIME ETHERS USING SPIROBORATE ESTERS
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Page/Page column 23, (2008/06/13)
Asymmetric reduction of arylalkyl and pyridylalkyl ketoxime ether with borane catalyzed by several chiral spiroborates derived from non-racemic 1,2-amino alcohols are presented. Complete conversion of oxime to primary amine is highly dependant of the catalyst, source and amount of borane and temperature. The conversion and enantioselectivity is determined by the benzylic substitution of the oxime. After optimization, a catalyst derived from diphenyl valinol could, successfully, afford primary amines with good yield and enantioselectivity up to 99% ee. Using the developed methodology, other related non-racemic primary pyridyl alkyl methanamines were also prepared in high chemical yield and excellent enantioselectivity.
Catalytic activity of MCM-41-TBD in the selective preparation of carbamates and unsymmetrical alkyl carbonates from diethyl carbonate
Carloni, Silvia,De Vos, Dirk E.,Jacobs, Pierre A.,Maggi, Raimondo,Sartori, Giovanni,Sartorio, Raffaella
, p. 199 - 204 (2007/10/03)
The synthesis of carbamates 3 and unsymmetrical alkyl carbonates 5 by reaction of diethyl carbonate with aliphatic amines or alcohols has been realized by using as heterogeneous catalyst a hybrid organic-inorganic material prepared by anchoring TBD to MCM-41 silica. Products are obtained in high yield and very good selectivity and the solid catalyst can be recovered simply by filtration and reused for different cycles without apparent lowering of activity. A supported N -carbethoxyguanidinium active intermediate is proposed, and some spectroscopic data are shown to support the mechanistic hypothesis.
A practical procedure for the preparation of carbamates from azides
Ariza, Xavier,Urpi, Felix,Vilarrasa, Jaume
, p. 7515 - 7517 (2007/10/03)
A practical procedure for the direct conversion of azides to carbamates has been found. High yields are obtained when primary and secondary aliphatic azides, as well as α-azido esters, are treated in THF with Me3P and several chloroformates (ClCOOBn, ClCOOMe, ClCOOEt, ClCOOCH2CCl3, ClCOOCH2CH=CH2).
AN EFFICIENT METHOD FOR HYDROLYSIS OF N-MONOSUBSTITUTED AMIDES VIA ACETOXYPIVALIMIDES
Tsunoda, Tetsuto,Sasaki, Osamu,Ito, Sho
, p. 731 - 734 (2007/10/02)
Various N-monosubstituted carboxamides were efficiently hydrolyzed in two steps through acetoxypivalimides.The method can be applied to a wide range of amides without racemization of α-position of the acyl groups.The amines can also be recovered.
Chemical Ionization Mass Spectra of Urethanes
Wright, Andrew D.,Bowen, Richard D.,Jennings, Keith R.
, p. 1521 - 1528 (2007/10/02)
Chemical ionization mass spectra using methane as the reagent gas are reported for 33 urethanes of general structure RNHCO2C2H5 nH2n+1 (n=1-8), CH2CH=CH2, cyclo-C6H11, Ph, PhCH2, PhCH2CH2, and Ph(CH3)CH> and R2NCO2C2H5 nH2n+1 (n=1-4)>.Abundant MH+ ions are present in all the spectra, accompanied by satellite peaks corresponding to + and +.Four classes of fragment ions are of general importance in the spectra.Two of these, + and +, are associated with the CO2C2H5 group.The other two, corresponding to alkane and alkene elimination from MH+, arise from the RNH or R2N function.The mechanisms whereby these fragment ions are formed are discussed and their analytical utility is illustrated by reference to the spectra of the four isomeric C4H9NHCO2C2H5 and the eight isomeric C5H11NHCO2C2H5 compounds.The results of 2H-labelling studies are presented and a comparison is made between the methane and ammonia chemical ionisation spectra of selected urethanes.
