Molecular aggregates are receiving tremendous attention, demonstrating immense potential for biomedical applications in vitro and in vivo. For instance, the molecular aggregates of conventional fluorophores influence the electronic excitation states of the aggregates, causing characteristic photophysical property changes. A fundamental understanding of this classical relationship between molecular aggregate structures and photophysics has allowed for innovative biological applications. The chemical characteristics of drug molecules generally trigger the formation of colloidal aggregates, and this is considered detrimental to the drug discovery process. Furthermore, nano-sized supramolecular aggregates have been used in biomedical imaging and therapy owing to their optimal properties for in vivo utility, including enhanced cell permeability, passive tumor targeting, and convenient surface engineering. Herein, we provide an overview of the recent trends in molecular aggregates for biomedical applications. The changes in photophysical properties of conventional fluorophores and their biological applications are discussed, followed by the effects of conventional drug molecule-aggregates on drug discovery and therapeutics development. Recent trends in the investigation of biologically important analytes with aggregation-induced emission are discussed for conventional and unconventional fluorophores. Lastly, we discuss nano-sized supramolecular aggregates used in imaging and therapeutic purposes, with a focus on in vivo utilization.

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In last decade, nickel-catalyzed organic reactions made tremendous progress due to their distinctive redox character. It has unfolded many contemporary synthetic transformations namely cross-coupling, carbon-carbon bond cleavage and directed CÀ H functionalization to achieve the targeted medicinal organic molecules in a straightforward manner. Beyond these well documented approaches, dehydrogenative coupling a challenging bond forming strategy by expelling hydrogen from unfunctionalized coupling partners is less explored. In accord with this, nickel-catalyst has been studied to perform different class of dehydrogenative coupling between easily accessible substrates. Nickel catalyzed processes for the construction of carbon-carbon, carbon-heteroatom and heteroatom-heteroatom bonds by dehydrogenation are discussed herein in a sustainable manner.[a] Dr.

An efficient and general protocol for the synthesis of diaryl sulfones via the metal-free coupling of readily available diaryliodonium salts and arenesulfinates in PEG-400 under microwave irradiation has been developed. Utilizing this metal-free and ecofriendly protocol, we have prepared various diaryl sulfones in high yields and shorter reaction times under mild conditions. Furthermore, the coupling of diaryliodonium with arenesulfinate salts with and without copper iodide provides a convenient access to various diaryl sulfones with high selectivity.

Regioselective construction of crucial C-N and C-O bonds leading to N-arylquinolones and aryloxyquinolines has been accomplished by employing easily accessible diaryliodonium salts and quinolones in water under metal- and ligand-free conditions. This operationally simple strategy is significant due to mild reaction conditions, high product yields, recyclability of released iodoarenes and scalability to the gram level. The practical utility of the developed protocol was proved by the arylation of medicinally important heterocycles like acridin-9(10H)-one, 3-methylquinoxalin-2(1H)-one and 1H-benzo[d]imidazol-2(3H)-one.

Easily accessible heteroaromatic carboxylic acids and diaryliodonium salts were successfully employed to construct valuable 2-arylindoles and heteroaryl carboxylates in a regioselective fashion. C2-arylated indoles were produced using a Pd-catalyzed decarboxylative strategy in water without any base, oxidant, or ligand. Heteroaryl carboxylates were prepared under metal and base-free conditions. This protocol was successfully utilized to synthesize Paullone, a cyclin-dependent kinase (CDK) inhibitor.

An efficient and high-yielding protocol for the preparation of α-keto-1,3,4-oxadiazoles has been developed. Formation of α-keto-1,3,4-oxadiazoles involves the 2-iodoxybenzoic acid/tetraethylammonium bromide mediated oxidative cyclization of hydrazide-hydrazones generated in situ from the reaction of aryl glyoxal and hydrazides. This one-pot protocol is reasonably general for the preparation of α-keto-1,3,4-oxadiazoles under mild conditions in short reaction times.

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