James K. Murray

Generation and in situ Diels–Alder reactions of activated nitroethylene derivatives

Abstract Dienes readily undergo Diels–Alder reaction with CH 2 C(NO 2 )SO 2 Ph ( 2a ), CH 2 C(NO 2 )CO 2 Et ( 2b ), and CH 2 C(NO 2 )COPh ( 2c ), all observed in situ by 1 H NMR. The cycloadducts of 2a undergo S RN 1 reactions.

Ultrastable Artificial Binding Pairs as a Supramolecular Latching System: A Next Generation Chemical Tool for Proteomics

In this Commentary, we discuss cucurbit[7]uril-based ultrastable artificial binding pairs as a supramolecular latching system and how we envision this becoming important tools in proteomics. The limitations of current proteomic techniques are described with an emphasis on the lack of tools to answer questions about the complex and dynamic nature of the proteome. Our thoughts as to how artificial ultrastable binding pairs may be able to address these questions are given especially when they are combined with existing methods.

A facile preparation method for nanosized MOFs as a multifunctional material for cellular imaging and drug delivery

Abstract Tb-based metal-organic framework nanoparticles (Tb-MOF NPs) with good colloidal stability and stable fluorescence properties in an aqueous solution were prepared by a simple mechanical grinding of Tb-MOF with a biocompatible polymer surfactant (F127). The characteristic fluorescence property of Tb-MOF NPs allowed us to use this nanomaterial as a cell imaging probe. Efficient cellular uptake of Tb-MOF NPs apparently via an energy-dependent endocytosis was observed by confocal laser scanning microscopy. By taking advantage of the porous nature of the Tb-MOF NPs an anticancer drug (doxorubicin) was successfully loaded and delivered to kill cancer cells to demonstrate their usage as a drug delivery vehicle. This simple grinding method afforded a nanosized, multifunctional biomaterial that was used for cell imaging and drug delivery, and it can be extended to other MOFs to widen their applications.

Cucurbit[6]uril-based polymer nanocapsules as a non-covalent and modular bioimaging platform for multimodal in vivo imaging

Cucurbit[6]uril (CB[6])-based polymer nanocapsules (CB[6]PNs) were used as a multimodal platform for cancer-targeted in vivo bioimaging. By taking advantage of the strong and robust host–guest interaction between CB[6] and spermidine (spmd) under in vivo conditions, the surface of the CB[6]PNs was non-covalently modified with various spmd-conjugated functionalities in a modular manner. The CB[6]PNs modified with imaging probes and targeting ligands showed tumor targeted PET and NIR imaging in mice. This proof of concept demonstrates the potential of non-covalently modified nanomaterials in real world in vivo systems.

Self-Healable Supramolecular Hydrogel Formed by Nor-Seco-Cucurbit[10]uril as a Supramolecular Crosslinker

A supramolecular hydrogel was formed by a simple mixing of solutions of nor-seco-cucurbit[10]uril (NS-CB[10]) and adamantylamine-terminated 4-armed polyethylene glycol (AdA-4-arm-PEG). In the formation of the hydrogel, NS-CB[10] acted as a noncovalent crosslinker to form a ternary complex with two AdA moieties. The dynamic and selective nature of the host-guest interaction between NS-CB[10] and AdA enabled the supramolecular hydrogel to rapidly recover its physical properties after it was damaged. In addition, the recovered hydrogel retained its physical properties with negligible differences from those of the pristine material, even after multiple self-healing cycles. The NS-CB[10]-based hydrogel with the self-healing property may be useful for various biological applications such as drug delivery, cell therapy and tissue engineering.

Competing Diels–Alder reactions of activated nitroethylene derivatives and [3,3]-sigmatropic rearrangements of the cycloadducts

Diels-Alder reaction of nitroethylene derivatives with cyclohexa-1,3-diene afforded three pericyclic products some of which could be converted to others via a new [3,3]-sigmatropic rearrangement or via a Claisen rearrangement.