Synthesis of tetraaryl-p-benzoquinones and 2,3-diaryl-1,4-naphthoquinones via Suzuki–Miyaura cross-coupling reactions

An insight into recent developments of copper, silver and gold carbon dots: cancer diagnostics and treatment

Cancer is one of the most fatal diseases globally, however, advancement in the field of nanoscience specifically novel nanomaterials with nano-targeting of cancer cell lines has revolutionized cancer diagnosis and therapy and has thus attracted the attention of researchers of related fields. Carbon Dots (CDs)-C-based nanomaterials-have emerged as highly favorable candidates for simultaneous bioimaging and therapy during cancer nano-theranostics due to their exclusive innate FL and theranostic characteristics exhibited in different preclinical results. Recently, different transition metal-doped CDs have enhanced the effectiveness of CDs manifold in biomedical applications with minimum toxicity. The use of group-11 (Cu, Ag and Au) with CDs in this direction have recently gained the attention of researchers because of their encouraging results. This review summarizes the current developments of group-11 (Cu, Ag and Au) CDs for early diagnosis and therapy of cancer including their nanocomposites, nanohybrids and heterostructures etc. All The manuscript highlights imaging applications (FL, photoacoustic, MRI etc.) and therapeutic applications (phototherapy, photodynamic, multimodal etc.) of Cu-, Ag- and Au-doped CDs reported as nanotheranostic agents for cancer treatment. Sources of CDs and metals alogwith applications to give a comparative analysis have been given in the tabulated form at the end of manuscript. Further, future prospects and challenges have also been discussed.

Iron catalyzed C-C dehydrogenative coupling reaction: synthesis of arylquinones from quinones/hydroquinones

An atom-economical approach for the synthesis of arylquinones was achieved successfully via direct oxidative C-C dehydrogenative coupling reaction of quinones/hydroquinones with electron-rich arenes using an inexpensive Fe-I2-(NH4)2S2O8 system. The efficiency of this catalytic approach was established with a broad scope of substrates involving quinones and hydroquinones to give high yields (60-89%) of several arylated quinones. The present protocol is simple, practical, and shows good functional group tolerance.

A Suzuki Approach to Quinone-Based Diarylethene Photochromes

Diarylethene photochromes show promise for use in advanced organic electronic and photonic materials with burgeoning considerations for biological applications; however, these compounds typically require UV light for photoswitching in at least one direction, thus limiting their appeal. We here introduce a naphthoquinone-based diarylethene that switches between open and closed forms with visible light. The synthesis of this quinone diarylethene relies on Suzuki methodology, allowing for the inclusion of functional groups not otherwise accessible with current synthetic routes.

Regioselective Oxidative Arylation of Fluorophenols

A metal free and highly regioselective oxidative arylation reaction of fluorophenols is described. The relative position of the fluoride leaving group (i.e., ortho or para) controls the 1,2 or 1,4 nature of the arylated quinone product, lending versatility and generality to this oxidative, defluorinative, arylation concept.

Cyanohydrin formation of quinone appended benzaldehyde as a tool for selective colorimetric detection of cyanide in aqueous solution in a wide pH range

A Novel chemosensor R possessing napthoquinone substituted benzaldehyde has been successfully designed, synthesized and characterized using NMR and mass spectral techniques. The receptor exhibits striking colour change from pale yellow to intense green with sodium cyanide in DMF-H₂O (80-20% v/v) in a wide range of pH (3-12). Based on the results of spectral (UV-Vis, fluorescence and NMR), electrochemical and kinetic studies a plausible mechanism has been proposed for the cyanide detection process. The mechanism of sensing of cyanide by R is through the formation of cyanohydrin in acidic, neutral and basic solutions, which is the novelty of the receptor. The pseudo-first-order rate constants for the formation of cyanohydrin are found to be 2.9 × 10^-3, 3.9 × 10^-3 and 4.6 × 10^-3 min^-1 at pH values 5, 7 and 10, respectively in DMF-H₂O (80-20% v/v) medium, supporting the ability of R to form cyanohydrin with equal ease in different pH values. The results of Job's continuous variation method indicates a 1:2 (R:CN^-) stoichiometry for the interaction. The only minor drawback with the receptor is the time taken to impart visible colour change with cyanide ion, which is not instantaneous.

Iron-mediated site-selective oxidative C–H/C–H cross-coupling of aryl radicals with quinones: synthesis of β-secretase-1 inhibitor B and related arylated quinones

Phenoxy radicals were converted intoparasite selectiveC-aryl radicals and coupled with quinones, using an inexpensive FeCl₃–K₂S₂O₈system, to obtain several arylated quinones, in good to moderate yields.