Effects of Electronics, Aromaticity, and Solvent Polarity on the Rate of Azaquinone–Methide-Mediated Depolymerization of Aromatic Carbamate Oligomers
摘要:
This paper uses physical-organic studies on well-defined oligomers to establish design principles for creating aromatic poly(carbamates) that depolymerize from head-to-tail in low dielectric constant environments when exposed to specific applied signals. We show that either increasing electron density or decreasing the aromaticity of aromatic repeating units in poly(carbamates) increase the overall depolymerization rate. For example, a methoxybenzene-based repeating unit provides depolymerization rates that are 143X faster than oligomers that contain a benzene-based repeating unit. Furthermore, the rate of depolymerization in the methoxybenzene-based system is tolerant to low dielectric environments, whereas the benzene-based oligomers are not.
Self-Immolative Polymersomes for High-Efficiency Triggered Release and Programmed Enzymatic Reactions
作者:Guhuan Liu、Xiaorui Wang、Jinming Hu、Guoying Zhang、Shiyong Liu
DOI:10.1021/ja5030832
日期:2014.5.21
disassembly of blockcopolymer vesicles or polymersomes has been conventionally achieved via solubility switching of the bilayer-forming block, requiring cooperative changes of most of the repeating units. Herein we report an alternative approach by incorporating hydrophobic blocks exhibiting stimuli-triggered head-to-tail cascade depolymerization features. Amphiphilic blockcopolymers bearing this motif
Rhodium-Catalyzed Synthesis of Amides from Functionalized Blocked Isocyanates
作者:Joshua S. Derasp、André M. Beauchemin
DOI:10.1021/acscatal.9b02641
日期:2019.9.6
Isocyanates are useful building blocks for the synthesis of amides, although their widespread use has been limited by their high reactivity, which often results in poor functional group tolerance and a propensity to oligomerize. Herein, a rhodium-catalyzed synthesis of amides is described coupling boroxines with blocked (masked) isocyanates. The success of the reaction hinges on the ability to form
Programmable Microcapsules from Self-Immolative Polymers
作者:Aaron P. Esser-Kahn、Nancy R. Sottos、Scott R. White、Jeffrey S. Moore
DOI:10.1021/ja104812p
日期:2010.8.4
repair of damaged materials, microcapsules are needed that release their contents in response to a variety of physical and chemical phenomena, not just by direct mechanical rupture. Herein we report a general route to programmablemicrocapsules. This method creates core-shell microcapsules with polymeric shell walls composed of self-immolativepolymer networks. The polymers in these networks undergo a
Engineering Intracellular Delivery Nanocarriers and Nanoreactors from Oxidation-Responsive Polymersomes via Synchronized Bilayer Cross-Linking and Permeabilizing Inside Live Cells
作者:Zhengyu Deng、Yinfeng Qian、Yongqiang Yu、Guhuan Liu、Jinming Hu、Guoying Zhang、Shiyong Liu
DOI:10.1021/jacs.6b04115
日期:2016.8.24
sustained-release drugnanocarriers and long-acting in vivo nanoreactors. Also note that conventional polymersomes possess thick hydrophobic bilayers and compromised membrane permeability, rendering them as ineffective nanocarriers and nanoreactors. We herein report the fabrication of oxidation-responsive multifunctional polymersomes exhibiting intracellular milieu-triggered vesicle bilayer cross-linking