5325-60-0Relevant articles and documents
Hydroxy chalcogenide-promoted Morita-Baylis-Hillman Alkylation reaction: Intermolecular applications with alkyl halides as electrophiles
Gradillas, Ana,Belmonte, Efres,Da Silva, Rondes Ferreira,Perez-Castells, Javier
, p. 1935 - 1941 (2014/04/03)
Hydroxysulfides acted as catalysts to promote the Morita-Baylis-Hillman alkylation reaction of cyclohexenones and dihydropyridinones. The procedure worked efficiently with a variety of halides as electrophiles. Side reactions were in competition with the MBH alkylation, but fine-tuning the reaction conditions minimized their occurence.
Hydroxy Chalcogenide-Promoted Morita-Baylis-Hillman Alkylation Reaction: Intermolecular Applications with Alkyl Halides as Electrophiles
Gradillas, Ana,Belmonte, Efres,Da Silva, Rondes Ferreira,Prez-Castells, Javier
, p. 1935 - 1941 (2015/10/05)
Hydroxysulfides acted as catalysts to promote the Morita-Baylis-Hillman alkylation reaction of cyclohexenones and dihydropyridinones. The procedure worked efficiently with a variety of halides as electrophiles. Side reactions were in competition with the
Disiloxanes with cyclic or non-cyclic carbamate moieties as electrolytes for lithium-ion batteries
Jeschke, Steffen,Gentschev, Ann-Christin,Wiemhoefer, Hans-Dieter
supporting information, p. 1190 - 1192 (2013/03/13)
Novel liquid disiloxanes, containing an n-propylic spacer group between the disiloxane fragment and a cyclic or non-cyclic carbamate moiety, were synthesized and characterized as liquid electrolytes. The ionic conductivity, thermal properties, viscosity and relative permittivity of these new solvents have been investigated, taking into account steric factors.
N-substituted carbamates syntheses with alkyl carbamates as carbonyl source over Ni-promoted Fe3O4 catalyst
Shang, Jianpeng,Guo, Xiaoguang,Shi, Feng,Ma, Yubo,Zhou, Feng,Deng, Youquan
experimental part, p. 328 - 336 (2011/05/14)
A series of catalysts of magnetic iron oxide containing Ni with different nickel content were prepared with co-precipitation method and tested in the syntheses of N-substituted carbamates from various amines and alkyl carbamates. Under the optimized reaction conditions, various N-substituted carbamates were successfully synthesized with 90-98% isolated yield. The catalyst could be recovered based on the magnetic property of the catalyst and reused for five runs without deactivation. The catalysts were characterized with X-ray photoelectron spectroscopy, X-ray diffraction, temperature-programmed reduction, temperature-programmed desorption, and Moessbauer spectroscopy analyses. The results showed that the catalytic activity may be derived from the delicate synergy between Ni and Fe species resulted in specific basic sites. Quasi in situ FT-IR and isotopic tracer revealed that the formation of substituted urea was the key step and the N-substituted carbamate was formed via further alcoholysis of the substituted urea.
Efficient regio- And stereoselective formation of azocan-2-ones via 8-endo cyclization of α-carbamoyl radicals
Fang, Xinqiang,Liu, Kun,Li, Chaozhong
supporting information; experimental part, p. 2274 - 2283 (2010/05/01)
The iodine-atom-transfer 8-endo cyclization of α-carbamoyl radicals was investigated experimentally and theoretically. With the aid of Mg(CIO 4)2 and a bis(oxazoline) ligand, N- ethoxycarbonylsubstituted N-(pent-4-enyl)-2-iodoalkanamides underwent 8-endo cyclization leading to the formation of only the corresponding 3,5-trans-substituted azocan-2-ones in excellent yields. Similarly, the BF 3·OEt2/H2O-promoted reactions of N-ethoxycarbonyl-N-(2-allylaryl)-2-iodoalkanamides afforded exclusively the benzazocanone products with a 3,5-cis configuration in high yields. The bidentate chelation of substrate radicals not only significantly improved the efficiency of cyclization but also resulted in the change of stereochemistry of azocanone products from 3,8-iransto 3,8-cis. Theoretical calculations at the UB3LYP/6-31G* level revealed that the cyclization of N-carbonyl- substituted α-carbamoyl radicals occurs via the E-conformational transition states without the presence of a Lewis acid. On the other hand, the cyclization proceeds via the Z-conformational transition states when the substrates form the bidentate chelation with a Lewis acid. In both cases, the 8-endo cyclization is always fundamentally preferred over the corresponding 7-exo cyclization. The complexed radicals having the more rigid conformations also allow the better stereochemical control in the iodine-atom-abstraction step. To further understand the reactivity of a-carbamoyl radicals, the competition between the 8-endo and 5-exo cyclization was also studied. The results demonstrated that the 8-endo cyclization is of comparable rate to the corresponding 5-exo cyclization for a-carbamoyl radicals with fixed Z-conformational transition states. As a comparison, the 8-endo mode is fundamentally preferred over the 5-exo mode in the cyclization of NH-amide substrates because the latter requires the Z-conformational transition states, whereas the former proceeds via the more stable E-conformational transition states.
Synthesis of P,N-heterocycles from ω-amino-H-phosphinates: Conformationally restricted α-amino acid analogs
Queffelec, Clemence,Ribiere, Patrice,Montchamp, Jean-Luc
supporting information; experimental part, p. 8987 - 8991 (2009/04/11)
(Chemical Equation Presented) P,N-Heterocycles (3-hydroxy-1,3- azaphospholane and 3-hydroxy-1,3-azaphosphorinane-3-oxide) are synthesized in moderate yield from readily available ω-amino-H-phosphinates and aldehydes or ketones via an intramolecular Kabachnik-Fields reaction. The products are conformationally restricted phosphinic analogs of α-amino acids. The multigram-scale syntheses of the H2N(CH2) nPO2H2 phosphinic precursors (n = 1, 2, 3) and some derivatives are also described.
Electrochemically promoted C-N bond formation from amines and CO 2 in ionic liquid BMIm-BF4: Synthesis of carbamates
Feroci,Orsini,Rossi,Sotgiu,Inesi
, p. 200 - 203 (2007/10/03)
A new electrochemical procedure for the synthesis of organic carbamates from amines and carbon dioxide has been developed using selective cathodic reduction of carbon dioxide in CO2-saturated room-temperature ionic liquid BMIm-BF4 solutions containing amines 1a-j, followed by addition of EtI as an alkylating agent. The synthesis was carried out under mild (PCO2 = 1.0 atm, t = 55 °C) and safe conditions, and the use of volatile and toxic solvents and catalysts (according to the growing demand for ecofriendly synthetic methodologies), as well as of any supporting electrolyte (for a very easy workup of the reaction mixture), was avoided. Carbamates 2a-j were isolated in good to high yields.
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.
The reaction of amines with an electrogenerated base. Improved synthesis of arylcarbamic esters
Feroci, Marta,Inesi, Achille,Rossi, Leucio
, p. 963 - 966 (2007/10/03)
The electrogenerated base of 2-pyrrolidone reacts with amines and anilines yielding the corresponding alkyl and aryl carbamates, after addition of carbon dioxide and ethyl iodide. Arylcarbamic esters are obtained in very good yields under mild reaction conditions with respect to the methods so far reported. (C) 2000 Elsevier Science Ltd.
