Convergent synthesis of geometrically disassembling dendrimers using Cu(I)-catalyzed C-O bond formation.

The convergent synthesis of geometrically degradable dendrimers based on the 2,4-bis(hydroxymethyl)phenol subunit is presented. The key step of the synthetic scheme involves the CuI/3,4,7,8-tetramethyl-1,10-phenanthroline-catalyzed coupling of aryl iodides and alcohols. The synthesis and disassembly of these compounds is discussed.

Geometric disassembly of dendrimers: dendritic amplification.

Geometric disassembly of dendritic structures was realized by a cascade cleavage reaction triggered by an initially stimulated group at the dendrimer core. Release of an exponential number of dendrimer fragments was a result of the branching nature of the cleavage pathway. Evidence for the completion of the disassembly process was provided by the absorbance peak of the p-nitrophenoxide ion that was covalently installed at the periphery of the dendrons for this purpose. The release by dendrimer disassembly of an exponential number of dendrimer fragments that serve to alter the properties of a system is termed dendritic amplification.

Dendrimer disassembly by benzyl ether depolymerization.

The disassembly of dendritic structures was realized by a cascade cleavage reaction triggered by an initially stimulated group in the dendrimer periphery. A depolymerizable backbone was engineered into prototypical dendritic structures. Evidence for the completion of the disassembly process is provided by the absorbance peak of the p-nitrophenoxide ion that was intentionally installed at the focal point of the dendrons. Observation of the UV spectra during the disassembly process supports a stepwise cascade cleavage proceeding from the periphery into the core.