87962-87-6Relevant academic research and scientific papers
Room temperature N-arylation of amino acids and peptides using copper(i) and β-diketone
Sharma, Krishna K.,Sharma, Swagat,Kudwal, Anurag,Jain, Rahul
supporting information, p. 4637 - 4641 (2015/04/27)
A mild and efficient method for the N-arylation of zwitterionic amino acids, amino acid esters and peptides is described. The procedure provides the first room temperature synthesis of N-arylated amino acids and peptides using CuI as a catalyst, diketone as a ligand, and aryl iodides as coupling partners. The method is equally applicable for using relatively inexpensive aryl bromides as coupling partners at 80 °C. Using this procedure, electronically and sterically diverse aryl halides, containing reactive functional groups were efficiently coupled in good to excellent yields.
Palladium-catalyzed coupling reaction of amino acids (esters) with aryl bromides and chlorides
Ma, Fangfang,Xie, Xiaomin,Ding, Lina,Gao, Jinsheng,Zhang, Zhaoguo
experimental part, p. 9405 - 9410 (2011/12/14)
The bulky and electron-rich MOP type ligands and Pd(dba)2 combinations showed high efficiency for the coupling reactions of amino acids and inactive aryl halides to give N-aryl amino acids. Under the catalytic conditions, not only α-amino acids, but also β-, γ-, and δ-amino acids have been coupled with aryl chlorides in moderate to high yields; in the case of optically pure β-amino acids as substrates, the optical purities of the coupling products retained.
Novel hydroxyphenylurea dual inhibitor against Acyl-CoA: Cholesterol acyltransferase (ACAT) and low density lipoprotein (LDL) oxidation as antiatherosclerotic agent
Nakao, Kazuya,Kubota, Hitoshi,Yasuhara, Mikiko,Saito, Keiko,Suzuki, Toshikazu,Ohmizu, Hiroshi,Shimizu, Ryo
, p. 853 - 861 (2007/10/03)
Novel hydroxyphenylurea derivatives were synthesized and their inhibitory potency evaluated against acyl-CoA: cholesterol acyltransferase ACAT. Quantitative structure-activity relationship analysis revealed that their ACAT inhibitory activities were controlled by the hydrophobicity of the whole molecule, the substitution pattern of urea moiety, and the existence of carboxylic acid. The derivatives with strong activities inhibited foam cell formations. Moreover, these compounds showed antioxidative effects against low density lipoprotein LDL, owing to their characteristic 3-tert-butyl-2-hydroxy-5-methoxyphenyl substructure. Based on the mechanism of atherosclerosis generation, this hydroxyphenylurea-type dual inhibitor against both ACAT and LDL oxidation is expected to be a promising drug for atherosclerosis. Copyright
4,4'-Di-tert-butylbiphenyl-Catalysed Reductive Opening of Azetidines with Lithium: A Direct Preparation of 3,N-Dilithioalkylamines
Almena, Juan,Foubelo, Francisco,Yus, Miguel
, p. 5775 - 5782 (2007/10/02)
The reaction of N-phenylazetidine 1a with an excess of lithium powder and a catalytic amount of 4,4'-di-tert-butylbiphenyl (5 molpercent) in THF at -15 deg C leads to the corresponding dianion 2a, which by treatment with different electrophiles (H2O, D2O, ButCHO, PhCHO, (CH2)5CO, PhCH=NPh, CO2) yields, after hydrolysis with water, the expected functionalysed amines 3aa-ah.The same method applied to N-isopropyl-2-phenylazetidine 1c affords compounds 3ca-ce (electrophiles: H2O, D2O, PhCHO, Me2CO, CH2=CHCH2Br) resulting from the more stable benzylic intermediate 2c.Finally, the regiochemistry in the reductive opening of 2-methyl-N-phenylazetidine 1d followed by deuterolysis was studied: a mixture of both regioisomers 3da+3da' was obtained, the ratio being the oposite as expected according to the stability of both intermediates 2d and 2d'.
Kinetics and Equilibria of Ring Closure through an Amide Linkage. Part 2. 1-Aryl-2-pyrrolidones
Abdallah, Jassim M.,Moodie, Roy B.
, p. 1243 - 1250 (2007/10/02)
Equilibrium constants, and rate constants for forward and reverse reactions, for ring closure of several 4-(arylamino)butanoic acids to 1-aryl-2-pyrrolidones in aqueous acid, together with ionisation constants of the former group of compounds, are reported.The equilibrium constants K at 50 deg C between neutral protonic forms of open-chain and ring compounds are related to the ionisation constants of the nitrogen-protonated 4-(arylamino)butanoic acids, K1, by the equation: log K=0.70 (pK1)+1.53.The value of K for pyrrolidone itself was measured for comparison.Studies of 18O exchange reveal that (except in the case of the substrate which bears the most electron-withdrawing substituents in the aryl ring, namely 2,4-dinitro) the rate-determining step lies between the tetrahedral intermediate and the ring compound.Substituent effects and solvent deuterium isotope effects on the hydronium-ion catalysed reaction are consisitent with a transition state close to the neutral tetrahedral intermediate.The effects of methyl substituents in the heterocyclic ring on rate and equilibrium constants have also been studied.The variation of K with temperature, and derived thermodynamic parameters, are reported in two cases.
