A Light-Activated Reaction Manifold

Abstract

We introduce an efficient reaction manifold where the rate of a thermally induced ligation can be controlled by a photonic field via two competing reaction channels. The effectiveness of the reaction manifold is evidenced by following the transformations of macromolecular chain termini via high-resolution mass spectrometry and subsequently by selective block copolymer formation. The light-controlled reaction manifold consists of a so-called o-quinodimethane species, a photocaged diene, that reacts in the presence of light with suitable enes in a Diels-Alder reaction and undergoes a transformation into imines with amines in the absence of light. The chemical selectivity of the manifold is controlled by the amount of ene present in the reaction and can be adjusted from 100% imine formation (0% photo product) to 5% imine formation (95% photo product). The reported light-controlled reaction manifold is highly attractive because a simple external field is used to switch the selectivity of specific reaction channels.

Red‐Light‐Controlled Release of Drug–Ru Complex Conjugates from Metallopolymer Micelles for Phototherapy in Hypoxic Tumor Environments

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Photoactivation of Anticancer Ru Complexes in Deep Tissue: How Deep Can We Go?

“…Phototherapy causes minimal side effects for normal tissues because light provides high spatial resolution and allows activation of the phototherapeutic agents at target sites only . Most photoresponsive materials, such as photoactivated platinum, coumarin‐caged and pyrene‐caged prodrugs are sensitive to UV or short‐wavelength visible light. However, UV or short‐wavelength visible light is problematic for biomedical applications, because these wavelengths cannot penetrate deeply into tissue .…”

Controlling thermal reactivity with different colors of light

“…Interestingly, the exploitation of different colors of light as a gate to switch between thermally and photochemically activated reaction channels is almost non-explored and constitutes a key next frontier within the realm of reaction control 31 . Indeed, simply selecting the outcome of chemical one-pot processes by the absence or presence of a photonic field or by different wavelengths will allow for the development of, e.g., sub-diffraction photoresists 32 – 34 or multi-area-selective surface lithography.…”