Regiospecific Cleavage of S–N Bonds in Sulfonyl Azides: Sulfonyl Donors

Abstract

Sulfonyl azides have been widely used as sulfonamido, diazo, and azido donors, as well as all-nitrogen 1,3-dipoles donors in synthetic chemistry. Here, the sulfonyl azides were used as efficient sulfonyl donors, which is very unusual. Trifluoromethanesulfonic acid-induced formation of the sulfonyl cation reactive species from sulfonyl azides was developed and used for the first time to couple various inactivated arenes to prepare sulfones at ambient temperature.

Highly specific imaging of mRNA in single cells by target RNA-initiated rolling circle amplification

“…It has enabled the in situ detection of widespread targets such as mitochondrial DNA, 15 mRNA 14,16,17 and miRNA. 18–20 We have designed a seal probe and RCA method enabling the visualization of individual short miRNAs in situ in single cells. 18 Chu et al also developed a target-primed RCA method for the highly sensitive and selective in situ detection of miRNA expression.…”

Imaging multiple microRNAs in living cells using ATP self-powered strand-displacement cascade amplification

“…The enzyme-based rolling circle amplification (RCA) technique for the highly sensitive analysis of intracellular low-abundance miRNA has been developed, 29 , 30 which indeed required the liposome-based complicated cellular delivery of enzymes or other agents. Several enzyme-free hybridization chain reaction (HCR) techniques for imaging low-abundance miRNA in living cells have also been explored, 31 but the limited quantity of transfected probes may restrict the sensitivity.…”

Simultaneous visualization of the subfemtomolar expression of microRNA and microRNA target gene using HILO microscopy

“… 25 Nevertheless, the direct observation of miRNAs inside the cells was demonstrated using atomic force microscopy, 26 DNA-driven gold-upconversion nanoparticle pyramids, 27 cascade hybridization reactions, 28 and rolling circle amplification combined with a triple-helix probe. 29 Furthermore, a sensitive method for visualizing individual miRNAs based on rolling circle amplification has been reported by Deng et al 30 In addition, a two-color imaging method for the simultaneous observation of miR-21 and let-7a via a hybridization chain reaction with graphene oxide as a carrier has been demonstrated. 31 However, the loss of miRNA during cell treatment such as hybridization and washing limits the application of the imaging techniques for ultra-trace miRNA visualization.…”