1078-70-2Relevant academic research and scientific papers
SnCl2-catalyzed synthesis of carbamates from renewable origin alcohols
da Silva, Márcio José,Chaves, Diego Morais
, p. 1169 - 1180 (2018)
Effects of structure and reactivity of renewable origin alcohols in the conversion and selectivity of the SnCl2-catalyzed reactions in the presence and absence of urea were assessed. Convenient simple and suitable method for the synthesis of carbamates from renewable origin alcohols and urea in one-step are provided. We have assessed the activity of SnCl2 catalyst, a commercially affordable Lewis acid, in reactions of urea alcoholysis with different natural origin alcohols (geranyl, neryl, bornyl, cinnamyl, α-terpinyl and benzyl alcohols), aiming to synthesize carbamates, which are biologically active compounds, building blocks in organic synthesis and raw material to synthesize polyurethanes. The low cost of urea, the water tolerant catalyst and phosgene free reaction are positive aspects of this carbamates synthesis process. The different reaction pathways were assessed. A mechanism was proposed based on FT-IR experiments and experimental data.
Indium(III)-Catalyzed Synthesis of Primary Carbamates and N-Substituted Ureas
Jain, Isha,Malik, Payal
supporting information, p. 93 - 97 (2021/11/26)
An indium triflate-catalyzed synthesis of primary carbamates from alcohols and urea as an ecofriendly carbonyl source has been developed. Various linear, branched, and cyclic alcohols were converted into the corresponding carbamates in good to excellent yields. This method also provided access to N-substituted ureas by carbamoylation of amines. All the products were obtained by simple filtration or crystallization, without the need for chromatographic purification. Mechanistic investigations suggest that the carbamoylation reaction proceeds through activation of urea by O-coordination with indium, followed by nucleophilic attack by the alcohol or amine on the carbonyl center of urea. The inexpensive and easily available starting materials and catalyst, the short reaction times, and the ease of product isolation highlight the inherent practicality of the developed method.
Microwave-Assisted 1,3-Dioxa-[3,3]-Sigmatropic Rearrangement of Substituted Allylic Carbamates: Application to the Synthesis of Novel 1,3-Oxazine-2,4-dione Derivatives
Bou Zeid, Samar,Eid, Samar,Najjar, Fadia,Macé, Aurélie,Rivilla, Ivan,Cossío, Fernando P.,Dorcet, Vincent,Roisnel, Thierry,Carreaux, Fran?ois
, (2021/11/22)
In a first instance, the effect of the microwave irradiation on the 1,3-Dioxa-[3,3]-sigmatropic rearrangement of aryl allylic carbamates was investigated. Under these new conditions, the reaction acceleration was clearly highlighted compared to convention
Further development of the tin-catalyzed transcarbamoylation reaction
Hasegawa, Tomoyuki,Ichikawa, Yoshiyasu,Masuda, Toshiya,Minami, Takahiro,Morishita, Yukinori,Ochi, Rika,Sato, Hiroshi
, p. 2373 - 2378 (2020/08/19)
Studies carried out to further develop tin-catalyzed trans-carbamoylation reactions demonstrated that transcarbamoylation of cinnamyl alcohol in the context of allyl cyanate-to-isocyanate rearrangement can be efficiently carried out on a ten-gram scale and that tin-catalyzed transcarbamoylation is a valuable alternative to the method using trichloroacetyl isocyanate. In addition, methyl carbamate was found to be an economical carabamoyl donor in tin-catalyzed transcarbamoylation, which showed broad functional group tolerance and allowed a streamlined workup procedure. Finally, a unique synthetic method was developed for the preparation of carbamate-tethered terpene glycoconjugates.
1,3-Dioxa-[3,3]-sigmatropic Oxo-Rearrangement of Substituted Allylic Carbamates: Scope and Mechanistic Studies
Agirre, Maddalen,Henrion, Sylvain,Rivilla, Ivan,Miranda, José I.,Cossío, Fernando P.,Carboni, Bertrand,Villalgordo, José M.,Carreaux, Fran?ois
, p. 14861 - 14881 (2019/01/04)
An unexpected 1,3-dioxa-[3,3]-sigmatropic rearrangement during the treatment of aryl- and alkenyl-substituted allylic alcohols with activated isocyanates is reported. The reorganization of bonds is highly dependent on the electron density of the aromatic
Iron-catalyzed reaction of urea with alcohols and amines: A safe alternative for the synthesis of primary carbamates
Pe?a-López, Miguel,Neumann, Helfried,Beller, Matthias
, p. 2233 - 2238 (2017/07/25)
A general study of the iron-catalyzed reaction of urea with nucleophiles is here presented. The carbamoylation of alcohols allows for the synthesis of N-unsubstituted (primary) carbamates, including present drugs (Felbamate and Meprobamat, without the necessity to apply phosgene and related derivatives. Using amines as nucleophiles gave rise to the respective mono-and disubstituted ureas via selective transamidation reaction. These atom-economical transformations provide a direct and selective access to valuable compounds from cheap and readily available urea using a simple Lewis-acidic iron(Icatalyst.
Substrate scope and stereocontrol in the Rh(II)-catalysed oxyamination of allylic carbamates
Unsworth, William P.,Lamont, Scott G.,Robertson, Jeremy
, p. 7388 - 7394 (2017/09/12)
Application of a modified Du Bois protocol for rhodium-stabilised nitrenoid generation to a variety of allylic carbamates results in 4-acetoxymethyl-1,3-oxazolidin-2-one derivatives with moderate to high levels of stereocontrol.
Iron(II)-catalyzed intramolecular aminohydroxylation of olefins with functionalized hydroxylamines
Liu, Guan-Sai,Zhang, Yong-Qiang,Yuan, Yong-An,Xu, Hao
supporting information, p. 3343 - 3346 (2013/04/23)
A diastereoselective aminohydroxylation of olefins with a functionalized hydroxylamine is catalyzed by new iron(II) complexes. This efficient intramolecular process readily affords synthetically useful amino alcohols with excellent selectivity (dr up to > 20:1). Asymmetric catalysis with chiral iron(II) complexes and preliminary mechanistic studies reveal an iron nitrenoid is a possible intermediate that can undergo either aminohydroxylation or aziridination, and the selectivity can be controlled by careful selection of counteranion/ligand combinations.
Intramolecular iron(ii)-catalyzed aminobromination of allyl N-tosyloxycarbamates
Kamon, Takuma,Shigeoka, Daisuke,Tanaka, Tetsuaki,Yoshimitsu, Takehiko
body text, p. 2363 - 2365 (2012/04/11)
Allyl N-tosyloxycarbamates are found to be catalytically transformed into β-brominated oxazolidinones with FeBr2/n-Bu4NBr in t-BuOH. The Royal Society of Chemistry 2012.
Metal-free intramolecular aziridination of allylic carbamates mediated by hypervalent iodine compounds
Deng, Qing-Hai,Wang, Jing-Cui,Xu, Zhen-Jiang,Zhou, Cong-Ying,Che, Chi-Ming
, p. 2959 - 2967 (2011/10/19)
An efficient and practical hypervalent iodine compound mediated metal-free intramolecular aziridination reaction of allylic carbamates was developed. Analytically pure aziridines were obtained in high yields by simple filtration of the reaction mixture. I
