1241680-63-6Relevant academic research and scientific papers
Recoverable Dendritic Phase-Transfer Catalysts that Contain (+)-Cinchonine-Derived Ammonium Salts
Rull, Jordi,Jara, José Juan,Sebastián, Rosa M.,Vallribera, Adelina,Nájera, Carmen,Majoral, Jean-Pierre,Caminade, Anne-Marie
, p. 2049 - 2056 (2016)
Four new phosphorus dendrimeric phase-transfer catalysts are prepared that contain 12 (+)-cinchoninium salts on the surface obtained by the quaternisation of the quinuclidinic N atom. The asymmetric alkylation of a glycinate Schiff base with benzyl bromide is used as a benchmark reaction, and the dendrimeric catalyst that contains an allyl group on the O-9 hydroxy group of the cinchonine units is the most active. The recovery and reuse of the catalyst are possible for five consecutive runs without loss of activity and with only a slight decrease in enantioselectivity. If other electrophiles are used, substituted benzyl bromides give better results than other activated alkyl bromides to afford the corresponding R amino acid derivatives. A comparison of these results with those reported previously for similar cinchoninium salts shows that dendrimers could be a better support than other polymers for this type of organocatalysis.
Synthesis and biological evaluation of asymmetric gramicidin S analogues containing modified d-phenylalanine residues
van der Knaap, Matthijs,Engels, Eefje,Busscher, Henk J.,Otero, Jose M.,Llamas-Saiz, Antonio L.,van Raaij, Mark J.,Mars-Groenendijk, Roos H.,Noort, Daan,van der Marel, Gijsbert A.,Overkleeft, Herman S.,Overhand, Mark
supporting information; experimental part, p. 6318 - 6328 (2011/02/26)
The synthesis of new analogues of the cationic antimicrobial peptide gramicidin S, having a modified d-phenylalanine residue, their antibacterial properties against several Gram positive and negative strains, as well as their hemolytic activity is reporte
