119020-01-8Relevant articles and documents
Condensation approach to aliphatic oligourea foldamers: Helices with N-(Pyrrolidin-2-ylmethyl)ureido junctions
Fremaux, Juliette,Fischer, Lucile,Arbogast, Thomas,Kauffmann, Brice,Guichard, Gilles
, p. 11382 - 11385 (2011)
Caught in a fold: A simple and efficient coupling strategy to make aliphatic oligourea foldamers is reported. Crystal structures show that the pyrrolidine units (red; see picture) do not impair the 2.5-helical folding of the oligoureas. This modular strategy enables assembly of long helical segments containing non-adjacent pyrrolidine units as exemplified by the synthesis of a helix that is approximately 40 long.
Synthesis and in vivo evaluation of 11C-labeled (1,7-dicarba-closo-dodecaboran-1-yl)-N-{[(2S)-1-ethylpyrrolidin-2-yl]methyl} amide
G?mez-Vallejo, Vanessa,Vázquez, Naiara,Gona, Kiran Babu,Puigivila, Maria,González, Mikel,Sebastián, Eneko San,Martin, Abraham,Llop, Jordi
, p. 209 - 214 (2014)
Boron clusters, and especially dicarba-closo-dodecaboranes, can be used as hydrophobic pharmacophores in the design of new drugs and radiotracers because of their hydrophobic character, spherical structure, and excellent chemical and photochemical stability. In the present paper, the synthesis and in vivo evaluation of 11C-labeled (1,7-dicarba-closo-dodecaboran-1-yl)-N- {[(2S)-1-ethylpyrrolidin-2-yl]methyl}amide, an analog of the D2 receptor ligand [11C]raclopride, is described. The radiosynthesis was approached by reaction of the demethylated precursor with [11C] CH3I in basic media; moderate radiochemical yields (18.2 ± 2.8%, decay corrected), and excellent radiochemical purities (>98%) were obtained in overall synthesis time of ~50 min. In vivo assays showed a biodistribution pattern with significant uptake in liver, kidneys and lungs at short times (t = 4 min) after administration and increasing accumulation in bladder at longer times (t ≥ 14.5 min). Although brain positron emission tomography scans showed good blood brain barrier penetration, the high unspecific uptake observed in different brain regions impedes its applicability as D2 receptor ligand.
Application of Proline-Derived (Thio)squaramide Organocatalysts in Asymmetric Diels-Alder and Conjugate Addition Reactions
Bagi, Péter,Dargó, Gyula,Drahos, László,Huszthy, Péter,Kis, Dávid,Kupai, József,Mátrav?lgyi, Béla,Nagy, Sándor,Tóth, Blanka
, (2022/02/22)
The synthesis of chiral proline-derived squaramide and thiosquaramide organocatalysts, which are capable of the dual activation in asymmetric reactions is reported. The (thio)squaramide moiety can form hydrogen bonds to activate the substrates and to stereocontrol the reaction, while the pyrrolidine unit can form enamines to activate carbonyl compounds via aminocatalysis. Comparing the performance of thiosquaramide to squaramide, the Diels Alder reaction of (anthracen-9-yl)acetaldehyde and trans-?-nitrostyrene was examined, which has been investigated in the literature using quantum chemical calculations. Both squaramide and thiosquaramide gave excellent yields (up to 99%) and enantiomeric excess values (up to 98%). Moreover, their catalytic performance was compared in conjugate addition of lawsone to ?,?-unsaturated ?-keto ester.
D -Prolyl-2-(trifluoromethylsulfonamidopropyl)pyrrolidine: An Organocatalyst for Asymmetric Michael Addition of Aldehydes to β-Nitroalkenes at Ambient Conditions
Gorde, Amol B.,Ramapanicker, Ramesh
, p. 1523 - 1533 (2019/02/07)
Four 2-(trifluoromethylsulfonamidoalkyl)pyrrolidines and their d-prolinamides were prepared and screened as organocatalysts for the Michael addition reaction of aldehydes with β-nitroalkenes at rt and without the use of additives. d-Prolyl-2-(trifluoromet
