2835-30-5Relevant academic research and scientific papers
2,2,2-Trifluroenthanol promoted synthesis of unsymmetrical ureas from dioxazolones and amines via tandem lossen rearrangement/condensation process
Li, Jian,He, Wang,Lei, Pan,Song, Jiacheng,Huo, Jiyou,Wei, Hongbo,Bai, Hongjin,Xie, Weiqing
supporting information, p. 3590 - 3600 (2021/10/07)
A 2,2,2-trifluroenthanol (TFE) promoted synthesis of unsymmetric ureas was described. This approach enabled the construction of a variety of ureas from the readily prepared and easy-to-handle dioxazolones and amines via tandem Lossen rearrangement/condensation process. The reaction featured mild conditions for the urea synthesis under metal-free conditions, which was successively applied in the scale-up synthesis of herbicides Monuro and Isoproturon.
A Fe3O4?SiO2/Schiff Base/Pd Complex as an Efficient Heterogeneous and Recyclable Nanocatalyst for One-Pot Domino Synthesis of Carbamates and Unsymmetrical Ureas
Inaloo, Iman Dindarloo,Majnooni, Sahar
, p. 6359 - 6368 (2019/11/05)
A palladium-catalyzed domino method for the direct synthesis of carbamates and ureas has been developed by using readily available and economical starting materials (aryl halide, carbon monoxide, sodium azide, amines and alcohols) in a one-pot approach. The domino process underwent carbonylation, Curtius rearrangement, and nucleophilic addition. This protocol provides a step-economical and highly efficient reaction to access the wide range of valuable carbamates, symmetrical and unsymmetrical ureas with high yields under remarkable mild reaction conditions that are important factors in pharmaceutical science, biochemistry and agricultural industries. Furthermore, the magnetically recoverable nanocatalyst (Fe3O4?SiO2/Pd(II)) can be conveniently and swiftly recycled using external magnet and reused at least for seven times without noticeable loss of its catalytic activity.
Bond-Weakening Catalysis: Conjugate Aminations Enabled by the Soft Homolysis of Strong N-H Bonds
Tarantino, Kyle T.,Miller, David C.,Callon, Ted A.,Knowles, Robert R.
supporting information, p. 6440 - 6443 (2015/06/08)
The ability of redox-active metal centers to weaken the bonds in associated ligands is well precedented, but has rarely been utilized as a mechanism of substrate activation in catalysis. Here we describe a catalytic bond-weakening protocol for conjugate a
An efficient transformation of ethers to N,N′-disubstituted ureas in a Ritter type reaction
Panduranga, Veladi,Basavaprabhu,Sureshbabu, Vommina V.
, p. 975 - 979 (2013/04/10)
A simple, mild, and an alternative protocol for the preparation of N,N′-disubstituted ureas from readily available ethers and cyanamides as starting materials is described. The protocol explores the reactivity of ether in a Ritter type reaction with cyanamide in the presence of BF 3·Et2O and resulting in the formation of N,N′-disubstituted urea. Divinyl ether as well as MTBE (methyl tert-butyl ether) can be employed as ether components to afford allyl and tert-butyl ureas respectively.
Iron(III) catalysed synthesis of unsymmetrical di and trisubstituted ureas - A variation of classical Ritter reaction
Basavaprabhu, Hosamani,Sureshbabu, Vommina V.
, p. 2528 - 2533 (2012/04/23)
An application of the classical Ritter reaction for the synthesis of unsymmetrical di and trisubstituted ureas catalyzed by FeCl3 is described. The protocol is of significant interest in view of the easy availability of precursors, mild reaction conditions employed and interestingly its applicability for the alkylation of alcohols capable of forming stable carbocationic intermediates even to the sterically hindered moieties. The Royal Society of Chemistry 2012.
Ionic liquid mediated one-pot synthesis of 6-aminouracils
Chavan, Sunil S.,Degani, Mariam S.
supporting information; experimental part, p. 296 - 299 (2012/03/26)
A novel, one-pot synthesis of 6-aminouracils via in situ generated ureas and cyanoacetylureas in the presence of an ionic liquid catalyst, 1,1,3,3-tetramethylguanidine acetate, is described. The catalyst can be recycled for five consecutive runs without loss of activity. The mechanism for the ring closure of cyanoacetylurea to 6-aminouracil is also discussed.
A convenient one-pot synthesis of asymmetric 1,3,5-triazine-2,4,6-triones and its application towards a novel class of gonadotropin-releasing hormone receptor antagonists
Guo, Zhiqiang,Wu, Dongpei,Zhu, Yun-Fei,Tucci, Fabio C.,Pontillo, Joseph,Saunders, John,Xie, Qiu,Struthers, R. Scott,Chen, Chen
, p. 693 - 698 (2007/10/03)
A convenient one-pot synthetic route was developed for the preparation of asymmetric 1,3-dialkyl-1,3,5-triazine-2,4,6-triones from readily available alkyl- or aryl-isocyanates, primary amines and N-chlorocarbonyl isocyanate in excellent yields. Subsequent alkylation with N-protected amino alcohols afforded the desired 1,3,5-triazine-2,4,6-triones in good yields. This methodology was applied to the synthesis of a chemical library acting as antagonists of the hGnRH receptor.
Manganese dioxide in a new role of Sulfur extrusion in thioamides
Radha Rani,Rahman,Bhalerao
, p. 1953 - 1958 (2007/10/02)
A simple and efficient procedure for the mild conversion of thioamides to amides in good yields using active manganese dioxide is described.
Enzymatic Oxidative Conversion of Thio to Oxo by Baker's Yeast in Thiocarbamates and Thioureas
Kamal, Ahmed,Rao, Maddamsetty V.,Rao, Adari B.
, p. 655 - 656 (2007/10/02)
The enzymatic conversion of aryl allylthiocarbamates and 1-allyl-3-arylthioureas by baker's yeast to the corresponding carbamates and ureas in good yields is described.
