161196-99-2Relevant articles and documents
Ammonium Chloride-Promoted Rapid Synthesis of Monosubstituted Ureas under Microwave Irradiation
Lan, Chunling Blue,Auclair, Karine
supporting information, p. 5135 - 5146 (2021/10/19)
Monosubstituted ureas are important scaffolds in organic chemistry. They appear in various biologically active compounds and serve as versatile precursors in synthesis. Monosubstituted ureas were originally prepared using toxic and hazardous phosgene equivalents. Modern methods include transamidation of urea and nucleophilic addition to cyanate salts, both of which suffer from a narrow substrate scope due to the need for a strong acid and prolonged reaction times. We hereby report that ammonium chloride can promote the reaction between amines and potassium cyanate to generate monosubstituted ureas in water. This method proceeds rapidly under microwave irradiation and tolerates a broad range of functional groups. Unlike previous strategies, it is compatible with other nucleophiles, acid-labile moieties, and most of the common protecting groups. The products precipitate out of solution, allowing facile isolation without column chromatography.
Development of Potent 3-Br-isoxazoline-Based Antimalarial and Antileishmanial Compounds
Basilico, Nicoletta,Conti, Paola,Coser, Consuelo,Galbiati, Andrea,Parapini, Silvia,Tamborini, Lucia,Taramelli, Donatella,Zana, Aureliano
supporting information, p. 1726 - 1732 (2021/11/01)
Starting from the structure of previously reported 3-Br-isoxazoline-based covalent inhibitors of P. falciparum glyceraldehyde 3-phosphate dehydrogenase, and with the intent to improve their metabolic stability and antimalarial activity, we designed and synthesized a series of simplified analogues that are characterized by the insertion of the oxadiazole ring as a bioisosteric replacement for the metabolically labile ester/amide function. We then further replaced the oxadiazole ring with a series of five-membered heterocycles and finally combined the most promising structural features. All the new derivatives were tested in vitro for antimalarial as well as antileishmanial activity. We identified two very promising new lead compounds, endowed with submicromolar antileishmanial activity and nanomolar antiplasmodial activity, respectively, and a very high selectivity index with respect to mammalian cells.
Bismuth trichloride–mediated cleavage of phenolic methoxymethyl ethers
Obaro-Best, Oghale,Reed, Jack,Norfadilah, Alya A. F. B.,Monahan, Ryan,Sunasee, Rajesh
supporting information, p. 586 - 593 (2016/06/08)
A simple and efficient method for removal of phenolic methoxymethyl ethers in the presence of 30?mol% of bismuth trichloride in acetonitrile/water is described. Notable features of the cleavage protocol entail use of an ecofriendly bismuth reagent, ease of handling, low cost, operational simplicity, and good functional group compatibility. A number of structurally varied phenolic methoxymethyl ethers were cleaved in good to excellent yields.
Silver-catalyzed nitrogenation of alkynes: A direct approach to nitriles through C≡C bond cleavage
Shen, Tao,Wang, Teng,Qin, Chong,Jiao, Ning
supporting information, p. 6677 - 6680 (2013/07/25)
Three in one blow! A novel direct transformation of alkynes into nitriles by a silver-catalyzed nitrogenation reaction through C≡C bond cleavage has been developed. This research provides both a new application for alkynes in organic synthesis, and valuable mechanistic insights into nitrogenation chemistry. Copyright
Practical one-pot conversion of aryl bromides and β-bromostyrenes into aromatic nitriles and cinnamonitriles
Ishii, Genki,Harigae, Ryo,Moriyama, Katsuhiko,Togo, Hideo
, p. 1462 - 1469 (2013/02/25)
Various aryl bromides were efficiently converted into the corresponding aromatic nitriles in good yields by the treatment with Mg turnings and subsequently DMF, followed by treatment with molecular iodine and aq NH 3. The same treatment of aryl bromides, which are weakly reactive to Mg turnings, with iPrMgCl·LiCl and subsequently DMF, followed by the treatment with molecular iodine and aq NH3 also afforded the corresponding aromatic nitriles in good yields. On the other hand, when N-formylpiperidine was used instead of DMF, p-substituted β-bromostyrenes were converted into the corresponding p-substituted cinnamonitriles, i.e., α,β-unsaturated nitriles, in good to moderate yields by the same procedure. The reactions were carried out by means of a simple experimental procedure and did not require any toxic metal cyanides or expensive rare metals. Therefore, the present reactions are practical and environmentally benign one-pot methods for the preparation of aromatic nitriles, cinnamonitriles, and aliphatic nitriles from aryl bromides, β-bromostyrenes, and alkyl bromides, respectively, through the formation of Grignard reagents and their DMF or N-formylpiperidine adducts.
Convenient Method for the ortho-Formylation of Phenols
Hofslokken, Nini U.,Skattebol, Lars
, p. 258 - 262 (2007/10/03)
Phenolic derivatives are formylated selectively ortho to the hydroxy group by paraformaldehyde with magnesium dichloride-triethylamine as base. With alkyl-substituted phenols excellent yields of the corresponding salicylaldehyde derivatives were obtained. Similar results were obtained with chloro-substituted phenols and with 3- and 4-methoxyphenol, while 2-methoxyphenol was unreactive. A good yield of methyl 3-formyl-4-hydroxybenzoate was obtained by this method as well, but generally phenols with electron-attracting groups reacted sluggishly; the long reaction times required caused the formation of by-products, particularly MOM-derivatives of the phenols.
A new one pot method for the conversion of aldehydes into nitriles using hydroxyamine and phthalic anhydride
Wang, Eng-Chi,Lin, Gow-Juin
, p. 4047 - 4050 (2007/10/03)
The aryl and alkyl aldehydes were readily converted to give the corresponding nitrites in good yields using hydroxyamine and phthalic anhydride as reagents in one pot.
Synthesis and Conformational Behavior of Rhodium(I) Metallohosts Derived from Diphenylglycoluril
Coolen, Hein K. A. C.,Leeuwen, Piet W. N. M. van,Nolte, Roeland J. M.
, p. 4739 - 4747 (2007/10/03)
The design and synthesis of molecules containing both a substrate-binding cavity and a nearby catalytically active metal center is a useful approach to the development of synthetic systems that function according to the principles of enzymes.To this end the receptor molecule 2a, derived from diphenylglycoluril, was functionalized with triaryl phosphite ligands to give the recoptor ligand 2d. exchange reactions of 2d with (diketonate)Rh(CO)2, (diketone = acetylacetone, dibenzoylmethane, or dipivaloylmethane) led to the formation of the metallohosts 3a-c, respectively.The properties and conformational behavior of these metal complexes were studied by NMR techniques.Reaction of compounds 3 with H2 in the presence of a small excess of additional triphenyl phosphite yields the rhodium(I) hydride complex 5.The metallohosts are capable of binding dihydroxybenzene guests in their cavities by hydrogen bonding and ?-? stacking interactions.On binding a substrate the conformational behavior of hosts 3a-c was affected considerably.
