2645-36-5Relevant academic research and scientific papers
Hydroamination and Hydrophosphination of Isocyanates/Isothiocyanates under Catalyst-Free Conditions
Zhu, Xiancui,Xu, Mengchen,Sun, Jinrong,Guo, Dianjun,Zhang, Yiwei,Zhou, Shuangliu,Wang, Shaowu
, p. 5213 - 5218 (2021/10/19)
Symmetrical and unsymmetrical N,N’-disubstituted as well as trisubstituted ureas/thioureas by the hydroamination of isocyanates/isothiocyanates, and various phosphathioureas by the hydrophosphination of isothiocyanates have been synthesized in good to excellent yields under catalyst-free and mild conditions. This protocol is also applicable for the efficient synthesis of chiral ureas and thioureas and common herbicides, such as fenuron and monuron.
Catalyst-free synthesis of substituted pyridin-2-yl, quinolin-2-yl, and isoquinolin-1-yl carbamates from the corresponding hetaryl ureas and alcohols
Baykov, Sergey V.,Boyarskaya, Irina A.,Boyarskiy, Vadim P.,Geyl, Kirill K.,Kasatkina, Svetlana O.
, p. 6059 - 6065 (2021/07/21)
A novel catalyst-free synthesis ofN-pyridin-2-yl,N-quinolin-2-yl, andN-isoquinolin-1-yl carbamates utilizes easily accessibleN-hetaryl ureas and alcohols. The proposed environmentally friendly technique is suitable for the good-to-high yielding synthesis of a wide range ofN-pyridin-2-yl orN-quinolin-2-yl substituted carbamates featuring electron-donating and electron-withdrawing groups in the azine rings and containing various primary, secondary, and even tertiary alkyl substituents at the oxygen atom (48-94%; 31 examples). The DFT calculation and experimental study showed that the reaction proceeds through the intermediate formation of hetaryl isocyanates. The method can be applied to obtainN-isoquinolin-1-yl carbamates, although in lower yields, and ethyl benzo[h]quinolin-2-yl carbamate has also been successfully synthesized (68%).
Lanthanum(III) Trifluoromethanesulfonate Catalyzed Direct Synthesis of Ureas from N-Benzyloxycarbonyl-, N -Allyloxycarbonyl-, and N -2,2,2-Trichloroethoxycarbonyl-Protected Amines
Bui, Tien Tan,Kim, Hee-Kwon
supporting information, p. 997 - 1002 (2020/06/17)
A novel lanthanum triflate mediated conversion of N -benzyloxycarbonyl-, N -allyloxycarbonyl-, and N -trichloroethoxycarbonyl-protected amines into nonsymmetric ureas was discovered. In this study, lanthanum triflate was found to be an effective catalyst for preparing various nonsymmetric ureas from protected amines. A variety of protected aromatic and aliphatic carbamates reacted readily with various amines in the presence of lanthanum triflate to generate the desired ureas in high yields. This result demonstrated that this novel lanthanum triflate catalyzed preparation of ureas from Cbz, Alloc, and Troc carbamates can be employed for the formation of various urea structures.
CaI2-Catalyzed direct transformation of: N -Alloc-, N -Troc-, and N -Cbz-protected amines to asymmetrical ureas
Tran, Van Hieu,Kim, Hee-Kwon
, p. 14093 - 14101 (2019/09/18)
A novel and facile CaI2-catalyzed direct synthesis of asymmetrical ureas from N-Alloc-, N-Troc-, and N-Cbz-protected amines is developed. In this study, the efficient reaction of Alloc-, Troc-, and Cbz-carbamates with amines in the presence of catalytic CaI2 successfully generated various asymmetrical ureas. This catalytic synthetic procedure provided the desired ureas via reactions of these protected aromatic and aliphatic amines with various amines in high yields without side products. This suggests that novel direct synthesis of ureas from Alloc-, Troc-, and Cbz-carbamates can be a promising approach for the synthesis of useful ureas.
Biochemical and microbiological evaluation of: N-aryl urea derivatives against mycobacteria and mycobacterial hydrolases
Vartak, Abhishek,Goins, Christopher,De Moura, Vinicius Calado Nogueira,Schreidah, Celine M.,Landgraf, Alexander D.,Lin, Boren,Du, Jianyang,Jackson, Mary,Ronning, Donald R.,Sucheck, Steven J.
, p. 1197 - 1204 (2019/07/25)
A focused library of 24 N-aryl urea derivatives was prepared and evaluated against serine esterases of Mycobacterium tuberculosis (Mtb) Rv3802c and Mtb Ag85C. The members of the library were evaluated for both selectivity and mode of inhibition. Furan-bas
Facile direct synthesis of unsymmetrical ureas from N-Alloc-, N-Cbz-, and N-Boc-protected amines using DABAL-Me3
Kang, Soosung,Kim, Hee-Kwon
, p. 4036 - 4046 (2018/06/13)
A practical synthetic method for the direct synthesis of unsymmetrically substituted ureas from N-Alloc-, N-Cbz-, and N-Boc-protected amines is described. In this study, efficient direct conversion of the Alloc-, Cbz-, and Boc-carbamate compounds to ureas was achieved in the presence of DABAL-Me3, an air stable and easily handled reagent. Using this reaction method, both protected aromatic and aliphatic amines were successfully transformed into various trisubstituted and tetrasubstituted ureas with high yields without side product. Our findings offer promising guidelines for direct preparation of useful ureas from N-Alloc-, N-Cbz-, and N-Boc-carbamates.
Chemoselective isocyanide insertion into the N-H bond using iodine-DMSO: Metal-free access to substituted ureas
Bora, Porag,Bez, Ghanashyam
supporting information, p. 8363 - 8366 (2018/08/03)
Insertion of isocyanides into the N-H bond gives access to many medicinally important and structurally diverse complex nitrogen-containing heterocycles. Although the transition metal catalyzed isocyanide insertion into the N-H bond is very common, polymerization of isocyanides in the presence of a transition metal and their strong coordination with metals are the common drawbacks. On the other hand, the inertness of most of the isocyanides towards amines in the absence of a metal catalyst has stymied the growth of the metal-free approach for isocyanide insertion into amines. As a result, only a handful of metal catalysed methods with limited substrate scopes have been reported for the synthesis of ureas via isocyanide insertion into amines and no metal-free version has been reported yet. Interestingly, chemoselective isocyanide insertion into amines has not been reported in the literature. We employed the I2-DMSO reagent system for the chemoselective synthesis of ureas, where isocyanides react with aliphatic amines only, while aromatic amines need a nucleophilic activator (DABCO) to facilitate the formation of ureas. This method gave direct and chemoselective access to ureas by evading the commonly used yet toxic isocyanates.
Synthesis of 11C-labelled ureas by palladium(II)-mediated oxidative carbonylation
Roslin, Sara,Brandt, Peter,Nordeman, Patrik,Larhed, Mats,Odell, Luke R.,Erikssoni, Jonas
, (2017/11/07)
Positron emission tomography is an imaging technique with applications in clinical settings as well as in basic research for the study of biological processes. A PET tracer, a biologically active molecule where a positron-emitting radioisotope such as carbon-11 has been incorporated, is used for the studies. Development of robust methods for incorporation of the radioisotope is therefore of the utmost importance. The urea functional group is present in many biologically active compounds and is thus an attractive target for incorporation of carbon-11 in the form of [11C]carbon monoxide. Starting with amines and [11C]carbon monoxide, both symmetrical and unsymmetrical 11C-labelled ureas were synthesised via a palladium(II)-mediated oxidative carbonylation and obtained in decay-corrected radiochemical yields up to 65%. The added advantage of using [11C]carbon monoxide was shown by the molar activity obtained for an inhibitor of soluble epoxide hydrolase (247 GBq/μmol-319 GBq/μ mol). DFT calculations were found to support a reaction mechanism proceeding through an 11C-labelled isocyanate intermediate.
Synthesis of ureas in the bio-alternative solvent Cyrene
Mistry, Liam,Mapesa, Kopano,Bousfield, Thomas W.,Camp, Jason E.
supporting information, p. 2123 - 2128 (2017/07/24)
Cyrene as a bio-alternative solvent: a highly efficient, waste minimizing protocol for the synthesis of ureas from isocyanates and secondary amines in the bio-available solvent Cyrene is reported. This method eliminated the use of toxic solvents, such as
Preparation method for alkyl/benzyl/aryl urea compounds through heterogeneous-phase catalysis
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Paragraph 0063-0071; 0072; 0073; 0074; 0076; 0078; 0082, (2016/10/09)
The invention discloses a preparation method for formula (I) compounds, and the compounds are obtained by reacting a formula (II) compound with a formula (III) compound in a solvent in carbon monoxide atmosphere under catalysis of a heterogeneous-phase pa
