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The development of light‐responsive molecular tools enables spatiotemporal control of biochemical processes with superior precision. Amongst these molecular tools, photolabile caging groups are employed to prevent critical binding interactions between a bioactive molecule and its corresponding target. Only upon irradiation with light, the bioactive is released in its 'active' form and is now readily available to bind to its target. Coumarin‐derived caging groups constitute one of the most popular classes of photolabile protecting groups, due to their facile synthetic accessibility, ease of tuning photophysical properties via structural modification and rapid photolysis reactions. Herein, we highlight the recent progress made on the development of coumarin‐derived caging groups, in which the red‐shifting of absorption spectra, improving aqueous solubility and tailoring sub‐cellular localisation has been of particular interest. [ABSTRACT FROM AUTHOR]

The development of new and effective therapeutics is reliant on the ability to study the underlying mechanisms of potential drug targets in live cells and multicellular systems. A persistent challenge in many drug development programmes is poor selectivity, which can obscure the mechanisms involved and lead to poorly understood modes of action. In efforts to improve our understanding of these complex processes, small molecule inhibitors have been developed in which their OFF/ON therapeutic activity can be toggled using light. Photopharmacology is devoted to using light to modulate drugs. Herein, we highlight the recent progress made towards the development of light‐responsive small molecule inhibitors of selected enzymatic targets. Given the size of this field, literature from 2015 onwards has been reviewed. [ABSTRACT FROM AUTHOR]

The development of a fluorescent LCK inhibitor that exhibits favourable solvatochromic properties upon binding the kinase is described. Fluorescent properties were realised through the inclusion of a prodan‐derived fluorophore into the pharmacophore of an ATP‐competitive kinase inhibitor. Fluorescence titration experiments demonstrate the solvatochromic properties of the inhibitor, in which dramatic increase in emission intensity and hypsochromic shift in emission maxima are clearly observed upon binding LCK. Microscopy experiments in cellular contexts together with flow cytometry show that the fluorescence intensity of the inhibitor correlates with the LCK concentration. Furthermore, multiphoton microscopy experiments demonstrate both the rapid cellular uptake of the inhibitor and that the two‐photon cross section of the inhibitor is amenable for excitation at 700 nm. [ABSTRACT FROM AUTHOR]

The underlying role that many kinases play in complex cellular pathways as well as disease remains unclear. To better understand the role that kinases play in both health and disease states, the use of light as an external stimulus to modulate kinase activity with high spatiotemporal resolution has gained increasing interest over the years. Herein we highlight the progress made towards the development of light‐responsive kinase enzymes and small molecule inhibitors. In these examples, photolabile caging groups and photoswitchable entities have been utilised to modulate either kinase activation or inhibition in a light‐controlled manner. [ABSTRACT FROM AUTHOR]

The syntheses of the tripodal tetraamine ligands 2‐(pyridin‐2‐yl)‐N,N‐bis(quinolin‐2‐ylmethyl)ethan‐1‐amine (DQPEA), N‐(pyridin‐2‐ylmethyl)‐2‐(quinolin‐2‐yl)‐N‐(2‐(quinolin‐2‐yl)ethyl)ethan‐1‐amine (DQEPMA), 2‐(pyridin‐2‐yl)‐N,N‐bis(2‐(quinolin‐2‐yl)ethyl)ethan‐1‐amine (DQEPEA), N,N‐bis(pyridin‐2‐ylmethyl)‐2‐(quinolin‐2‐yl)ethan‐1‐amine (QEDPMA), and 2‐(pyridin‐2‐yl)‐N‐(2‐(pyridin‐2‐yl)ethyl)‐N‐(2‐(quinolin‐2‐yl)ethyl)ethan‐1‐amine (QEDPEA) containing mixed quinolyl and pyridyl moieties are reported, with 2‐vinylquinoline being used to attach quinolylethyl arms to the aliphatic N atom. X‐ray crystal structures of [(Mn(DQPEA))2O2](ClO4)2 ⋅ (CH3CN)2, [Cu(DQPEA)NCCH3](ClO4)2, [Zn(DQPEA)NCCH3](ClO4)2, [Pd(DQEPEA)Cl]Cl ⋅ 11H2O are detailed, with four, five, and six‐coordination observed. In addition, the dimeric complex [(DPEA)Co(μ‐OH)3Co(DPEA)](ClO4)3 ⋅ 0.5H2O ⋅ MeCN containing the tridentate DPEA ligand formed by N‐dealkylation of QEDPEA is reported. Calculations suggest that the very short Co…Co distance of 2.5946(6) Å in this complex is unlikely to be due to a Co−Co bond. [ABSTRACT FROM AUTHOR]