Stereospecific Synthesis of Functionalized C5-Unsaturated Hydantoin Derivatives via a Three-Component Reaction
作者:Abdolali Alizadeh、Ehsan Sheikhi
DOI:10.1055/s-2008-1066993
日期:——
An effective route to functionalized C5-unsaturated hydantoin derivatives is described. This involves the reaction of a urea derivative, derived from the addition of a primary amine to an arylsulfonyl isocyanate, and a dialkyl acetylenedicarboxylate in the presence of isoquinoline.
A novel and simple approach to the synthesis of sulfonylureas has been reported. It involved the reaction of various amines with diphenyl carbonate to yield the corresponding carbamates, which subsequently reacted with different sulphonamides to produce different sulfonylureas in excellent yields. The first reaction of diphenyl carbonate with amines was carried out in aqueous:organic (H2O:THF, 90:10)
已经报道了一种新颖且简单的合成磺酰脲类的方法。它涉及各种胺与碳酸二苯酯的反应,以产生相应的氨基甲酸酯,其随后与不同的磺酰胺反应,以优异的产率产生不同的磺酰脲类。碳酸二苯酯与胺的第一反应是在室温下于水性:有机(H 2 O :THF,90 : 10)介质中进行的,以生成氨基甲酸酯,该氨基甲酸酯与磺酰胺反应后,直接通向磺酰脲类。上述方法避免了传统的多步骤方案,并且避免使用有害,刺激性,有毒和对水分敏感的试剂,例如光气,异氰酸酯和/或氯甲酸酯。
Cu(OAc)<sub>2</sub>-Mediated Reaction of C<sub>60</sub> with Ureas for the Preparation of Fulleroimidazolidinones
The Cu(OAc)2-mediated intermolecular diamination reaction of C60 with ureas allows the concise and efficient preparation of fulleroimidazolidinones involving the cleavage of two N–H bonds and formation of two C–N bonds. Both dialkylated and diarylated fulleroimidazolidinones can be synthesized using this method.
CO2 gas trapped with a primary or secondary amine as a carbamate salt in the presence of DBU reacts with triphenylphosphine and 1-chlorobenzotriazole (BtCl) to form a carbamoylbenzotriazole urea, which reacts with para-toluenesulfonamide under solvent-free conditions to produce N-sulfonyl ureas such as tolbutamide.
Optimization of methods for the generation of carbodiimides for zwitterionic 1,3-diaza-Claisen rearrangements
作者:Joel D. Walker、José S. Madalengoitia
DOI:10.1016/j.tetlet.2015.04.064
日期:2015.6
Strained, tertiary, allylic, amine 2-benzyl-2-azabicyclo[2.2.1]hept-5-ene reacts with in situ generated carbodiimides in a 1,3-diaza-Claisenrearrangement to afford structurally interesting bicyclic guanidines. Use of more electron deficient carbodiimides makes these rearrangements more facile; however, there are not sufficient methods for the synthesis of highly electron deficient carbodiimides. Herein