New methodologies for biological membrane mimics, electron-deficient assemblies, and cross-coupling of C-O based electrophiles.

摘要

Libraries of self-assembling dendrons provide accelerated approaches to the discovery of primary structures responsible to predict functions via first principles. Methodologies for the discovery of biological membrane mimics and electron-deficient assemblies were elaborated. Methodologies for nickel-catalyzed borylation and Suzuki-Miyaura cross-coupling of C-O based electrophiles are reported.;Convergent and divergent preparation of hydrophilic and hydrophobic dendrons combined with accelerated modular synthesis of libraries of amphiphilic Janus dendrimers were elaborated. Self-assembly in water analyzed by a combination of techniques including Dynamic Light Scattering, cryo-Transmission Electron Microscopy and confocal microscopy discovered a diversity of assemblies including dendrimersomes, cubosomes, ribbons, and solid lamellae. All assemblies are monodispersed and stable in time. The size of dendrimersomes is determined by their primary structure and predicted by lamellar spacing in bulk, using a new model. In corporation of cabohydrates in their hydrophilic part demonstrated bioactivity to biomedically relevant plant, bacterial and human lectins to demonstrate applications as biological membrane mimics, vaccines, and drug delivery devices.;Libraries of dendronized electron deficient perylenebisimides (3,4,5)12G1-m-PBI with m=0-4, (3,4,5)nG1-3-PBI (n=4-14) and (3,4,5)nG1-1-PBI (n = 6-12) were synthesized and their self-organized structures were analyzed by a combination of Differential Scanning Calorimetry , x-ray diffraction, molecular modeling, and solid state 1H NMR. Tetramers (m=0, 2,3,4) and dimers (m=1) of PBI are basic repeat units of supramolecular columns. At high temperature, 2D-hexagonal columnar phases were observed for m=3, n=8-14. At low temperature, 3D columnar arrays formed via kinetically controlled processes for n=12-14 and thermodynamically controlled processes for n=8-11. Upon annealing, the 3D columnar phase of m=3, n=8,9 transforms into a new thermodynamic product with monoclinic columnar structure through a self-repairing process which is not required for m=1, n=6-10 to optimize the TT-stacking structure. This transformation will facilitate design of dendronized PBI for organic electronics and solar cells.;Methodologies for neopentylglycolborylation of ortho-substituted electron rich and deficient aryl halides via Ni-mixed ligand catalytic systems were elaborated. Conditions for their cross-coupling with aryl/heteroaryl mesylates and sulfamates catalyzed 25 °C by the mixed ligand systems Ni(COD)2/PCy3 or Ni(1-Np)Cl(PPh 3)2/PCy3 were elaborated. A comparative study of Ni-based catalytic systems with various C-O electrophiles and neopentylglycolboronates provided orthogonal cross-coupling methodologies.