Discovery of Fluorogenic Diarylsydnone-Alkene Photoligation: Conversion of ortho-Dual-Twisted Diarylsydnones into Planar Pyrazolines

Abstract

A small library of diarylsydnones (DASyds) was constructed based on aryl-pairing combinations and subjected to click reaction toward alkenes under photoirradiation with high efficiency. We were able to demonstrate the utility of DASyds for highly fluorescent turn-on ligation targeting the trans-cyclooct-4-en-1-ol moieties on protein.

Spatiotemporal Resolved Live Cell Membrane Tracking through Photo‐click Reactions Enriched in Lipid Phase

“…As a proof, Tet 2 a precipitates out at 50 μM concentration, observed even by naked‐eye (Figure S11) [18] . The planar structure of Tet 2 a was presumably the reason for the poor solubility in contrast to the dual‐twisted diaryl structure of Syd 3 a [3f] . In addition, a Syd 3 a derived Syd 3 a‐C8 with an aliphatic tail was also subject to the same photo‐click reaction.…”

Photo-controllable bioorthogonal chemistry for spatiotemporal control of bio-targets in living systems

“…Other than tetrazoles, diarylsydnones were also reported to generate nitrile imines upon light irradiation. 39,40 To address the issue of competitive reactions of nitrile imine intermediates with carboxylic acid and hydroxyl groups in living systems, 41,42 efforts have been made to design and prepare tetrazole with bulky substitution groups to minimize side reactions in competition with TEPC ( Fig. 3 ).…”

Shining a Light on Bioorthogonal Photochemistry for Polymer Science

“…The double‐twisted conformation of diarylsydnones is detrimental to the thermal cycloaddition reactivity, but upon photoirradiation it decarbonylates to the highly reactive 1,3‐nitrile imine. [ 158 ] The scaffold twisting induced by the ortho ‐substituted diarylsydnones provide unique control of the reactivity and selectivity, through design of the 3D structure. Libraries of substituents for both the N 3 and C 4 terminus have been explored, to determine the effect of electron donating and withdrawing groups, as well as ring structure on the photoreactivity.…”

“…Libraries of substituents for both the N 3 and C 4 terminus have been explored, to determine the effect of electron donating and withdrawing groups, as well as ring structure on the photoreactivity. Upon formation of the reactive nitrile imine intermediate, the diarylsydnones are able to undergo rapid reaction with electron deficient and ring strained alkenes, [ 158 ] and ring strained alkynes. [ 159 ] To date these techniques have been used for in vitro protein and live cell labeling, but have not yet been demonstrated in vivo, owing to the single photon absorption profile, as with all other nitrile imine systems, currently limited to wavelengths lower than 450 nm.…”