o
-Phenylenediamine (OPD) can be readily oxidized
by several types of oxidants to generate fluorescent 2,3-diaminophenazine
(oxidized OPD, OPDox). The unique fluorescence response process during
the oxidation of OPD provides an important model for the design of
novel sensors. In recent years, a series of fluorescent and colorimetric
sensors have been developed based on the oxidation of OPD. In this
review, fluorescent and colorimetric sensors for the detection of
metal ions and small organic molecules are discussed. These sensing
processes exhibit distinguishable and prominent fluorescent and colorimetric
responses. The sensing systems include autocatalytic reactions and
using nanomaterials, carbon dots, or fluorophore labeled DNA as reference
fluorophore for fluorescent and colorimetric detection.
As versatile synthons, nitrenes have attracted great attention. Two research topics, including nitrene precursor development and nitrene‐based transformations, have been thoroughly investigated so far. Generally, different nitrene precursors under various metal catalysis have allowed for the differentiation of the reactivity of the resulting nitrene, thus enabling diverse C−H insertions, aziridinations, and sulfimidations with high reaction efficiency and reaction generality. Among the addition of nitrenes with unsaturated bonds, the reaction of nitrenes and alkynes is still in its initial stage, although various metal‐catalyzed transformations, typically, rhodium‐catalyzed sulfinamate‐derived nitrene/alkyne metalation, have been well‐developed. Two types of plausible mechanism, radical and electrophilic models, have been proposed. The simple preparation of acyl nitrenes and their enantioselective reaction with alkynes, as well as their applications in biologically interesting architectures, is of great interest. In this review, we would like to describe the reaction of nitrenes with alkynes under metal catalysis. To increase readability, this review will be presented according to mechanistic pathways and types of metal.
An effective synthetic entry to pyrimidobenzothiazoles via 6-endo-dig halocyclization of N-benzothiazol-2-yl alkynamides was developed under mild conditions with a broad substrate scope. Several multisubstituted α,β-enones were synthesized by using the...
Organosulfur compounds with unsymmetrical S–S bonds are usually called unsymmetrical disulfides and are widely used in the biological, medicinal, and chemical fields. Their versatility has guided the development of various new methods for the synthesis of disulfides. In recent years, the synthesis of disulfides by cross-dehydrogenation of thiols has attracted much attention due to its high atomic economy. Herein, this review summarizes progress toward the synthesis of unsymmetrical disulfides under chemical oxidation, electrooxidation, or photocatalysis by cross-dehydrogenation of thiols.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.