title: Synthesis and retrostructural analysis of libraries of AB3 and constitutional isomeric AB2 phenylpropyl ether-based supramolecular dendrimers.
abstract: We report the synthesis of methyl esters of 3-(4-hydroxyphenyl)propionic, 3-(3,4-dihydroxyphenyl)propionic, 3-(3,5-dihydroxyphenyl)propionic, and 3-(3,4,5-trihydroxyphenyl)propionic acids and their use in a convergent iterative strategy to prepare up to four generations of three libraries, one of 3,4,5- and two of constitutional isomeric 3,4- and 3,5-substituted 3-phenylpropyl dendrons. Each library contains 3-[3,4,5-tris(dodecyl-1-oxy)phenyl]propyl-, 3-[3,4-bis(dodecyl-1-oxy)phenyl]propyl-, 3-{3,4-bis[3-(4-dodecyl-1-oxyphenyl)propyl-1-oxy]phenyl}propyl-, and 3-{3,4,5-tris[3-(4-dodecyl-1-oxyphenyl)propyl-1-oxy]phenyl}propyl ether first-generation dendrons on their periphery and -CO2CH3, -COOH, and -CH2OH groups at their apex. Regardless of their generation number and their periphery, internal, and apex structures, these dendrons self-assemble into supramolecular dendrimers that self-organize into all periodic and quasi-periodic assemblies encountered previously and in several unencountered with architecturally related benzyl ether-based supramolecular dendrimers. A variety of porous columnar lattices that were previously obtained only from dendritic dipeptides and hollow supramolecular spheres were also discovered from these building blocks. The more flexible and less compact 3-phenylpropyl ether repeat units are stable under acidic conditions, facilitate a simpler synthetic strategy, provide faster dynamics of self-assembly into higher-order supramolecular structures of larger dimensions, exhibit lower transition temperatures than the corresponding benzyl ether homologues, and demonstrate the generality of the self-assembly concept based on amphiphilic dendrons.
authors.affiliation: Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA. percec@sas.upenn.edu
authors.forename: Virgil
authors.initials: V
authors.lastname: Percec
authors.forename: Mihai
authors.initials: M
authors.lastname: Peterca
authors.forename: Monika J
authors.initials: MJ
authors.lastname: Sienkowska
authors.forename: Marc A
authors.initials: MA
authors.lastname: Ilies
authors.forename: Emad
authors.initials: E
authors.lastname: Aqad
authors.forename: Jan
authors.initials: J
authors.lastname: Smidrkal
authors.forename: Paul A
authors.initials: PA
authors.lastname: Heiney
mesh_terms: D050091:Dendrimers / Q000138:chemical synthesis / Q000737:chemistry*; D007536:Isomerism; D008958:Models, Molecular; D010647:Phenyl Ethers / Q000737:chemistry*; D011422:Propionates / Q000138:chemical synthesis / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D050091:Dendrimers; D010647:Phenyl Ethers; D011422:Propionates