57965-29-4Relevant articles and documents
The C-F bond as a tool in the conformational control of amides
Briggs, Caroline R.S.,O'Hagan, David,Howard, Judith A.K.,Yufit, Dmitrii S.
, p. 9 - 13 (2003)
The conformation of 2-fluoro-N-(2-fluoroethyl)-propionamide 4 in the solid state indicates the influence of both a β-fluorine-amide gauche effect and an α-fluoroamide effect. The structure reveals the influence of two recently observed stereoelectronic effects associated with the C-F bond, which has resulted in the successful prediction of the solid state conformation of amide 4. A gauche relationship (-69.9°) was observed for atoms N(1)-C(4)-C(5)-F and a syn planar (2.0°) relationship was observed for N(1)-C(3)-C(2)-F. The paper demonstrates the predictive power of using the C-F bond as a tool in influencing the conformation of amides and peptides.
Prototypic 18F-Labeled Argininamide-Type Neuropeptide Y Y1R Antagonists as Tracers for PET Imaging of Mammary Carcinoma
Keller, Max,Maschauer, Simone,Brennauer, Albert,Tripal, Philipp,Koglin, Norman,Dittrich, Ralf,Bernhardt, Günther,Kuwert, Torsten,Wester, Hans-Jürgen,Buschauer, Armin,Prante, Olaf
supporting information, p. 304 - 309 (2017/03/17)
The neuropeptide Y (NPY) Y1 receptor (Y1R) selective radioligand (R)-Nα-(2,2-diphenylacetyl)-Nω-[4-(2-[18F]fluoropropanoylamino)butyl]aminocarbonyl-N-(4-hydroxybenzyl)argininamide ([18F]23), derived from the high-affinity Y1R antagonist BIBP3226, was developed for imaging studies of Y1R-positive tumors. Starting from the argininamide core bearing amine-functionalized spacer moieties, a series of fluoropropanoylated and fluorobenzoylated derivatives was synthesized and studied for Y1R affinity. The fluoropropanoylated derivative 23 displayed high affinity (Ki = 1.3 nM) and selectivity toward Y1R. Radiosynthesis was accomplished via 18F-fluoropropanoylation, yielding [18F]23 with excellent stability in mice; however, the biodistribution study revealed pronounced hepatobiliary clearance with high accumulation in the gall bladder (>100 %ID/g). Despite the unfavorable biodistribution, [18F]23 was successfully used for imaging of Y1R positive MCF-7 tumors in nude mice. Therefore, we suggest [18F]23 as a lead for the design of PET ligands with optimized physicochemical properties resulting in more favorable biodistribution and higher Y1R-dependent enrichment in mammary carcinoma.
Conformational preference in bis(porphyrin) tweezer complexes: A versatile chirality sensor for α-chiral carboxylic acids
Tanasova, Marina,Borhan, Babak
supporting information; experimental part, p. 3261 - 3269 (2012/07/01)
Metallated porphyrin tweezers have demonstrated a remarkable ability to function as reporters of absolute stereochemistry for a number of different classes of organic molecules. Flexibility in binding, however, can result in an ensemble of different Exciton Coupled Circular Dichroism (ECCD) active conformations that could lead to variable results. Linker flexibility was found to be a key determinant of binding conformation. Experimental results indicate that a balance between linker flexibility and rigidity could yield an optimum porphyrin tweezer that stabilizes a common conformation for all bound chiral guests. This leads to a more simplified approach to absolute stereochemical determination of asymmetry for small organic molecules. This was demonstrated by the use of a C3-linked zincated porphyrin tweezer that yields a common conformational preference for a variety of α-chiral carboxylic acids derivatized with a diamine carrier. Copyright