A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

• . Another example was reported by Rovis in 2013 using enal 108 in the presence of chiral NHC 109 to form extended Breslow intermediate 110 (Scheme 14) [52]. Photoisomerisation of 110 is then required for the following spirocyclisation reaction to intermediate 111 to proceed, which then releases the NHC

Potent hemithioindigo-based antimitotics photocontrol the microtubule cytoskeleton in cellulo

• Alexander Sailer,
• Franziska Ermer,
• Yvonne Kraus,
• Rebekkah Bingham,
• Ferdinand H. Lutter,
• Julia Ahlfeld and
• Oliver Thorn-Seshold

Beilstein J. Org. Chem. 2020, 16, 125–134, doi:10.3762/bjoc.16.14

• colchicine per se, aiming at compounds where one isomer would be almost biologically inactive such that light can be used to effect a photoisomerisation-based switch-on/switch-off of bioactivity. The end-to-end distance of the HTI scaffold is significantly longer than that in either the biaryl colchicine or

Ultrafast processes triggered by one- and two-photon excitation of a photochromic and luminescent hydrazone

• Alessandro Iagatti,
• Baihao Shao,
• Alberto Credi,
• Barbara Ventura,
• Ivan Aprahamian and
• Mariangela Di Donato

Beilstein J. Org. Chem. 2019, 15, 2438–2446, doi:10.3762/bjoc.15.236

• fluorescence intensity gradually decreases during the measurement, because of the photoisomerisation process, but the use of a low laser power (0.8 µJ/pulse) and the acquisition of a large number of frames (10000) in photon counting mode allowed the characterization of the emission properties of this form. The

Fluorinated azobenzenes as supramolecular halogen-bonding building blocks

• Esther Nieland,
• Oliver Weingart and
• Bernd M. Schmidt

Beilstein J. Org. Chem. 2019, 15, 2013–2019, doi:10.3762/bjoc.15.197

• because azobenzene is one of the simplest molecules that can undergo photoinduced isomerisation of its N=N central double bond. The photoisomerisation reaction in n→π and π →π* excited states has been studied with experimental [36][37][38] and theoretical approaches [39][40][41][42][43][44]. By

• the, also broadened, n→π* band of Z-A3. Apart from the photoisomerisation using light, azobenzenes A1–3 also undergo thermal back reaction, which we studied experimentally and theoretically. To gain insight into the effect of the iodine atoms on the thermal stability we investigated A1, A2 and A3 in

Multichromophoric sugar for fluorescence photoswitching

• Stéphane Maisonneuve,
• Rémi Métivier,
• Pei Yu,
• Keitaro Nakatani and
• Juan Xie

Beilstein J. Org. Chem. 2014, 10, 1471–1481, doi:10.3762/bjoc.10.151

• spectra were recorded under increasing irradiation times at 335 nm in order to follow the photoisomerisation of compound 2 (Figure 5), and corresponding UV–visible absorption spectra were measured, in order to correlate the absorption changes with the OF → CF conversion yield. Under 335 nm illumination

Synthesis and testing of the first azobenzene mannobioside as photoswitchable ligand for the bacterial lectin FimH

• Vijayanand Chandrasekaran,
• Katharina Kolbe,
• Femke Beiroth and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2013, 9, 223–233, doi:10.3762/bjoc.9.26

• adhesive surfaces. Keywords: azobenzene glycosides; bacterial adhesion; E/Z photoisomerisation; FimH antagonists; mannobiosides; molecular switches; sweet switches; Introduction Adhesion of bacteria to surfaces can be a severe problem both in vivo and in vitro. Hence, inhibition of bacterial adhesion by

• other hand, showed good solubility in polar organic solvents as well as in pure water. Thus, it was amenable to biological testing in aqueous buffer. E→Z photoisomerisation of azobenzene mannoside 6 was studied in DMSO, while isomerisation of azobenzene mannobioside 2 was performed in water

Flow photochemistry: Old light through new windows

• Jonathan P. Knowles,
• Luke D. Elliott and
• Kevin I. Booker-Milburn

Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229

Recent advances towards azobenzene-based light-driven real-time information-transmitting materials

• Jaume García-Amorós and
• Dolores Velasco

Beilstein J. Org. Chem. 2012, 8, 1003–1017, doi:10.3762/bjoc.8.113

• , associated with the n→π* transition. Upon UV-irradiation, the trans-to-cis photoisomerisation occurs, producing a decrease in the intensity of the 355 nm band and an increase in the 450 nm signal until the photostationary state is reached, that is, the inverse process of that shown in Figure 4 [44]. The

• possible pathways for the trans-to-cis photoisomerisation of azobenzenes [50][51][52]. The measurement of the volumes of activation for these processes provides unequivocal evidences regarding the operation of the inversion or rotation isomerisation mechanism [53][54]. The volumes of activation for the

Liquid-crystalline nanoparticles: Hybrid design and mesophase structures

• Gareth L. Nealon,
• Romain Greget,
• Cristina Dominguez,
• Zsuzsanna T. Nagy,
• Daniel Guillon,
• Jean-Louis Gallani and
• Bertrand Donnio

Beilstein J. Org. Chem. 2012, 8, 349–370, doi:10.3762/bjoc.8.39

• photoisomerisation and photodimerisation efficiency in these systems. Interesting examples of the potential application of this type of approach were shown by the grafting of similar azobenzene ligands 11 (Figure 12) to the surfaces of γ-Fe2O3 [67] and FePt [68] NPs, which exhibited a photoswitchable change in

Application of the diastereoselective photodeconjugation of α,β-unsaturated esters to the synthesis of gymnastatin H

• Ludovic Raffier and
• Olivier Piva

Beilstein J. Org. Chem. 2011, 7, 151–155, doi:10.3762/bjoc.7.21

• Ludovic Raffier Olivier Piva Université Lyon 1, UMR 5246 CNRS, Institut de Chimie et de Biochimie Moléculaire et Supramoléculaire, 69622 Villeurbanne, France 10.3762/bjoc.7.21 Abstract The asymmetric synthesis of gymnastatin H has been achieved by using the photoisomerisation of a conjugated

• ]. In this context, we have considered an alternative synthetic route to the fatty acid common to all gymnastatins according to a photoisomerisation–diastereoselective protonation sequence involving catalytic amounts of an achiral organocatalyst (e.g., amino alcohol 4b). Our goal was to describe the

Light-induced olefin metathesis

• Yuval Vidavsky and
• N. Gabriel Lemcoff

Beilstein J. Org. Chem. 2010, 6, 1106–1119, doi:10.3762/bjoc.6.127

• metathesis stands out as both academically motivating and practically useful. Starting from early tungsten heterogeneous photoinitiated metathesis, up to modern ruthenium methods based on complex photoisomerisation or indirect photoactivation, this survey of the relevant literature summarises past and

• present developments in the use of light to expedite olefin ring-closing, ring-opening polymerisation and cross-metathesis reactions. Keywords: catalysis; light activation; olefin metathesis; photoactivation; photoinitiation; photoisomerisation; RCM; ROMP; ruthenium; tungsten; Introduction The metal

• , complexes 33a, e, f, g were irradiated at 365 nm in the presence of RCM and ROMP substrates [78]. A summary of the results is presented in Table 4 and Table 5. The discovery that light irradiation induces photoisomerisation of the cis-dichloro complexes led to the proposed mechanism shown in Scheme 7. Thus