Ru(II)-Catalyzed Regiospecific C-H/O-H Oxidative Annulation to Access Isochromeno[8,1-ab]phenazines: Far-Red Fluorescence and Live Cancer Cell Imaging

A review on lawsone-based benzo[a]phenazin-5-ol: synthetic approaches and reactions

Phenazine systems are an important class of aza-polycyclic compounds that are easily found in nature and isolated as secondary metabolites primarily from Pseudomonas, Streptomyces, and a few other genera from soil or marine habitats. Moreover, various synthetic phenazine analogs are known for their pharmaceutical activities. Among various phenazines, benzo[a]phenazines are structural subunits in a variety of important natural products and have been given special attention due to their unique biological properties in various fields. In this review article, we highlight the synthesis of benzo[a]phenazin-5-ol derivatives from lawsone and benzene-1,2-diamines and their applications for the construction of a variety of five and six membered fused heterocycles such as pyranophenazines, spiropyranophenazines, pyridophenazines, furophenazines, benzochromenophenazines and oxazinophenazines during the period of 1995 to 2021.

Design and synthesis of spirooxindole–pyrrolidines embedded with indole and pyridine heterocycles by multicomponent reaction: anticancer and in silico studies

We report the synthesis of spirooxindole–pyrrolidines tethered with indole and pyridine heterocycles using 1,3-dipolar cycloaddition, and their anticancer activities and molecular docking studies.

Rh(iii)-Catalysed synthesis of cinnolinium and fluoranthenium salts using C-H activation/annulation reactions: organelle specific mitochondrial staining applications

The construction of a novel class of indazolo[2,1-a]cinnolin-7-ium and diazabenzofluoranthenium salts was developed by using Rh(iii)-catalyzed C-H activation/annulation reactions with 2-phenyl-2H-indazole, and internal alkynes, which resulted in structurally important polycyclic heteroaromatic compounds (PHAs). This reaction uses mild reaction conditions and has a high efficiency, low catalyst loading, and wide substrate scope. The overall catalytic process involves C-H activation followed by C-C/C-N bond formation. Furthermore, the synthesised cinnolinium/fluoranthenium salts exhibit potential fluorescence properties and 5i was targeted in particular for specific mitochondrial staining in order to investigate cancer cell lines.

Iridium-Catalyzed Direct C-H Amidation Producing Multicolor Fluorescent Molecules Emitting Blue-to-Red Light and White Light

We report a powerful strategy, iridium-catalyzed direct C-H amidation (DCA) for synthesizing various fluorescent sulfonamides that emit light over the entire visible spectrum with excellent efficiency (up to 99% yields). By controlling electronic characters of the resulting sulfonamides, a wide range of blue-to-red emissions was predictably obtained via an excited-state intramolecular proton-transfer process. Furthermore, we even succeeded in a white-light generation, highlighting that this DCA is an excellent synthetic method to prepare a library of fluorophores.

Harnessing hypervalent iodonium ylides as carbene precursors: C–H activation of N-methoxybenzamides with a Rh(iii)-catalyst

The first ever attempt at reacting hypervalent iodonium ylides with readily available N-methoxybenzamides by using a Rh(iii)-catalyst has been well explored.

The design and green synthesis of novel benzotriazoloquinolinyl spirooxindolopyrrolizidines: antimycobacterial and antiproliferative studies

Herein, we report the design and synthesis of novel series of potent anti-TB and antiproliferative benzotriazoloquinolinyl spirooxindolopyrrolizidines via an expeditious green approach by using ionic liquid ([Bmim]BF₄) under ultrasonication.

Rhodium(iii)-catalysed decarbonylative annulation through C–H activation: expedient access to aminoisocoumarins by weak coordination

Rh-Catalysed decarbonylative annulation of isatoic anhydrides with alkynes through C–H activation for the direct synthesis of 8-aminoisocoumarins has been developed.