16717-64-9Relevant articles and documents
Efficient Far-Red/Near-IR Absorbing BODIPY Photocages by Blocking Unproductive Conical Intersections
Shrestha, Pradeep,Dissanayake, Komadhie C.,Gehrmann, Elizabeth J.,Wijesooriya, Chamari S.,Mukhopadhyay, Atreyee,Smith, Emily A.,Winter, Arthur H.
, p. 15505 - 15512 (2020)
Photocages are light-sensitive chemical protecting groups that give investigators control over activation of biomolecules using targeted light irradiation. A compelling application of far-red/near-IR absorbing photocages is their potential for deep tissue activation of biomolecules and phototherapeutics. Toward this goal, we recently reported BODIPY photocages that absorb near-IR light. However, these photocages have reduced photorelease efficiencies compared to shorter-wavelength absorbing photocages, which has hindered their application. Because photochemistry is a zero-sum competition of rates, improvement of the quantum yield of a photoreaction can be achieved either by making the desired photoreaction more efficient or by hobbling competitive decay channels. This latter strategy of inhibiting unproductive decay channels was pursued to improve the release efficiency of long-wavelength absorbing BODIPY photocages by synthesizing structures that block access to unproductive singlet internal conversion conical intersections, which have recently been located for simple BODIPY structures from excited state dynamic simulations. This strategy led to the synthesis of new conformationally restrained boron-methylated BODIPY photocages that absorb light strongly around 700 nm. In the best case, a photocage was identified with an extinction coefficient of 124000 M-1 cm-1, a quantum yield of photorelease of 3.8%, and an overall quantum efficiency of 4650 M-1 cm-1 at 680 nm. This derivative has a quantum efficiency that is 50-fold higher than the best known BODIPY photocages absorbing >600 nm, validating the effectiveness of a strategy for designing efficient photoreactions by thwarting competitive excited state decay channels. Furthermore, 1,7-diaryl substitutions were found to improve the quantum yields of photorelease by excited state participation and blocking ion pair recombination by internal nucleophilic trapping. No cellular toxicity (trypan blue exclusion) was observed at 20 μM, and photoactivation was demonstrated in HeLa cells using red light.
Linking of Alcohols with Vinyl Azides
Wang, Yi-Feng,Hu, Ming,Hayashi, Hirohito,Xing, Bengang,Chiba, Shunsuke
, p. 992 - 995 (2016)
A protocol to link alcohols with vinyl azides has been established through fluoro- or bromo-alkoxylation of vinyl azides to provide α-alkoxy-β-haloalkyl azides. A series of primary and secondary alcohols including natural products and their derivatives such as sugars and steroids were successfully anchored with vinyl azides. The as-prepared cyanine dye linked testosterones were capable of rapid cell membrane imaging in real time.
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Hortmann,A.G. et al.
, p. 322 - 324 (1972)
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Photoredox-catalyzed synthesis of N-unsubstituted enaminosulfones from vinyl azides and sulfinates
Mulina, Olga M.,Ilovaisky, Alexey I.,Opatz, Till,Terent'ev, Alexander O.
supporting information, (2021/01/11)
A metal-free visible light photoredox-catalyzed synthesis of N-unsubstituted enaminosulfones from vinyl azides and sodium sulfinates in moderate to high yields is described. The reaction proceeds in ethanol and uses eosin Y as a readily available photocatalyst in combination with nitrobenzene as an electron shuttle. Taking into account the number of steps involved (generation of the sulfonyl radical, its addition to the double bond, elimination of molecular nitrogen with formation of an iminyl radical, followed by its reduction and protonation) as well as the number of redox-active reaction partners involved, the selectivity of the process is quite impressive.
Electrosynthesis of N-unsubstituted enaminosulfones from vinyl azides and sodium sulfinates mediated by NH4I
Mulina, Olga M.,Doronin, Mikhail M.,Terent'ev, Alexander O.
supporting information, (2021/10/16)
A wide range of N-unsubstituted enaminosulfones were obtained via electrochemical sulfonylation of vinyl azides with sulfonyl radicals generated from sodium sulfinates. The discovery of N-unsubstituted enaminosulfones synthesis is based on a unique ability of the azido group to eliminate the N2 molecule. The process is performed under constant current conditions in an experimentally convenient undivided electrochemical cell equipped with a graphite anode and a stainless steel cathode applying NH4I both as the redox catalyst and the supporting electrolyte.
