International audienceWe report here a straightforward route to polymer?peptide conjugates via the convenient synthesis of SG1-functionalized peptides able to initiate nitroxide-mediated polymerization (NMP). The NMP initiator SG1-functionalized peptide (SG1-GGGWIKVAV) was prepared by solid-phase peptide synthesis (SPPS) using an automated synthesizer, with a last step consisting of reaction between the carboxylic acid function of the MAMA-SG1 (BlocBuilder) alkoxyamine with the peptide terminal amine in the presence of benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate (PyBOP) as coupling agent. The resulting SG1-functionalized resin-attached peptide was used to perform the controlled NMP of styrene, leading after trifluoroacetic acid cleavage to the corresponding polystyrene?peptide conjugate. The latter was thoroughly characterized by UV spectrometry, gel permeation chromatography (GPC), 1H NMR, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)
We report a molecular design and concept using π‐system elongation and steric effects from helicenes surrounding a triphenylene core toward stable chiral polycyclic aromatic hydrocarbons (PAHs) with a maximal π‐distortion to tackle their aromaticity, supramolecular and molecular properties. The selective syntheses, and the structural, conformational and chiroptical properties of two diastereomeric large multi‐helicenes of formula C90H48 having a triphenylene core and embedding three [5]helicene units on their inner edges and three [7]helicene units at their periphery are reported based on diastereoselective and, when applicable, enantiospecific Yamamoto‐type cyclotrimerizations of racemic or enantiopure 9,10‐dibromo[7]helicene. Both molecules have an extremely distorted triphenylene core, and one of them exhibits the largest torsion angle recorded so far for a benzene ring (twist=36.9°).
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