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Photoredox catalysis provides a green and sustainable alternative for C−H activation of organic molecules that eludes harsh conditions and use of transition metals. The photocatalytic C−N borylation and C−H arylation mostly depend on the ruthenium and iridium complexes or eosin Y and the use of porphyrin catalysts is still in infancy. A series of novel 21‐thiaporphyrins (A2B2 and A3B type) were synthesized having carbazole/phenothiazine moieties at their meso‐positions and screened as catalysts for C−N borylation and C−H arylation. This paper demonstrates the 21‐thiaporphyrin catalyzed C−N borylation and het‐arylation of anilines under visible light. The method utilizes only 0.1 mol % of 21‐thiaporphyrin catalyst under blue light for the direct C−N borylation and het‐arylation reactions. A variety of substituted anilines were used as source for expensive and unstable aryl diazonium salts in the reactions. The heterobiaryls and aryl boronic esters were obtained in decent yields (up to 88 %). Versatility of the 21‐thiaporphyrin catalyst was tested by thiolation and selenylation of anilines under similar conditions. Mechanistic insight was obtained from DFT studies, suggesting that 21‐thiaporphyrin undergo an oxidative quenching pathway. The photoredox process catalyzed by 21‐thiaporphyrins offers a mild, efficient and metal‐free alternative for the formation of C−C, C−S, and C−Se bonds in aryl compounds; it can also be extended to borylation reaction. [ABSTRACT FROM AUTHOR]

Transition‐metal‐free photoredox catalysis was used for C−N borylation and C−H arylation with 0.1 mol % loading of 21‐thiaporphyrin. Under blue light, a thiaporphyrin catalyst was employed for the synthesis of boronic esters and hetero‐biaryl moieties having furan, thiophene or pyrrole. The methodology was also extended to synthesize diphenyl selenide and diphenyl sulfide derivatives. More information can be found in the Research Article by I. Gupta and co‐workers (DOI: 10.1002/chem.202401623)...By Anu Janaagal; Apoorv Kushwaha; Pranjali Jhaldiyal; T. J. Dhilip Kumar and Iti GuptaReported by Author; Author; Author; Author; Author [Extracted from the article]

[Display omitted] • Luminescent dipyrrinato complexes of Re and Ir with different types of co-ligands are discussed. • Re and Ir complexes are known as triplet sensitizers and they can generate significant amount of singlet oxygen. • Their synthetic methodologies, structures and optical properties are discussed in detail. • Their potential as cellular imaging agents or as photosensitizers for anticancer applications is discussed. Luminescent dipyrrinato complexes of d-block metals are well explored in literature for diverse applications in materials as well as in biology. They offer exceptional fine tuning of their electrochemical and optical properties with the variety of substitutions on the dipyrrin core. The development of mixed ligand type dipyrrinato complexes with heavy metals like: Ru, Os, Pd, Pt, Re, Ir are of great interest in biomedical applications due to significant ROS (Reactive Oxygen Species) generation, anti-microbial and anti-cancer applications. Such dipyrrinato complexes display bright triplet emission in the visible to red region due to heavy atom effect. This review is focused on the synthesis of luminescent dipyrrinato complexes of Re(I) and Ir(III) with different types of co-ligands around the metal center. The overviewed complexes are subcategorized further on the basis of metal and substitutions on the dipyrrin C-5 position or around the metal center. Re and Ir complexes of subporphyrin, N- confused porphyrin, sapphyrin, rubyrin and N- fused porphyrins have also been included. Their absorption and emission properties and their ability to work as triplet photosensitizers are discussed. Deliberations are made to understand their potential as cellular imaging agents and/or photosensitizers for ROS generation and phototherapy to treat cancer. [ABSTRACT FROM AUTHOR]

• Aza-BODIPYs are a class of organic dyes with strong absorption and emission in red-NIR region. • Aza-BODIPYs are subdivided into three categories: tetraaryl, ring fused, with extended conjugation. • Their synthetic methodologies, optical properties are discussed in detail. • Their applications in bio-imaging, PDT, solar cells, DSSCs and drug delivery systems have also been included. Aza-boron-dipyrromethenes (Aza-BODIPYs) are a class of dyes that display absorption and emission covering visible to NIR region. They can show NIR emission in the 700–1700 nm range and have diverse applications in biology, metal sensing and optical devices. Aza-BODIPYs have got attention for their superior spectral performances and applications in biology and material science. These dyes can be applied to fluorescence imaging, photodynamic/photothermal therapy, optoelectronics, etc. The aim of this review is to provide a comprehensive overview of streamlined development in the area of aza-BODIPY dyes and their applications in different areas. Firstly, general synthetic methodologies for the preparation of aza-BODIPYs are discussed. In the subsequent sections, the overview of tetra aryl, conformationally rigid and ring fused aza-BODIPYs, pyrrolopyrrole and extended aza-BODIPYs is presented. Later, sections describe the various applications of aza-BODIPYs in different areas such as: metal sensing, anion sensing, pH detectors, detection of biological analytes and energy transferring cassettes. The biological applications of aza-BODIPYs in fluorescence and photoacoustic imaging probes, as PDT and PTT agents, drug delivery systems are also discussed. Undoubtedly, it will be a one-stop solution for the science community to look for every structural aspect and application published from the year 2002 till May 2023. [ABSTRACT FROM AUTHOR]

The trans -A 2 B 2 type porphyrins bearing thiophene linked N -butylcarbazole or N -butylphenothiazine groups at the meso -positions were synthesized. Donor−acceptor (D−A) type meso- substituted porphyrins and their Zn(II) and Pd(II) complexes were studied by UV–vis absorption, fluorescence and electrochemical techniques. These porphyrins exhibited efficient energy transfer (∼78%) from the meso -donors (thiophene linked N -butylcarbazole or N -butylphenothiazine groups) to the porphyrin core. Also, the Soret band of porphyrins was noticeably broad, indicating significant communication between the meso -donor groups and the porphyrin core. The donor−acceptor interaction between the porphyrin core and the meso -donors was supported by X-ray analysis and DFT studies of these D-A systems. The photo-catalytic application of Pd(II) porphyrin was demonstrated by efficient singlet oxygen generation (68%) and effective oxidation of aromatic aldehydes to their corresponding carboxylic acids (up to 99%) in the presence of white light or sunlight. [Display omitted] • Donor-Acceptor (D-A) type trans -A 2 B 2 porphyrins and their Zn(II) and Pd(II) complexes are reported. • The D groups are linked via thiophene ring to the porphyrin core (A); porphyrins showed efficient energy transfer (78%) from D to A. • All the porphyrins were studied by UV–Vis absorption, fluorescence and cyclic voltammetry techniques. • Donor-Acceptor interaction between the porphyrin core and meso -donors was supported by the X-ray crystal analysis and DFT studies. • Pd(II) porphyrin was used as efficient catalyst for the photo-oxidation of aromatic aldehydes under white LED or sunlight. [ABSTRACT FROM AUTHOR]

This work is focused on the design and synthesis of homoleptic and heteroleptic dipyrrinato complexes with palladium at the centre. The C-5 position of the dipyrrin ligand was substituted with pentaflourophenyl/naphthalene/tetraphenylethylene moieties. Scanning electron microscopy (SEM) measurement revealed the formation of aggregates in binary solvents for the homoleptic Pd(II) complexes. These complexes showed enhanced emission with noticeable red shifts (20–30 nm) in the aggregated state, suggesting the formation of J-aggregates in a THF/water mixture. All of the Pd(II)dipyrrinato complexes exhibited strong absorption in the range of 440–560 nm; the DFT optimized geometries also showed absorption transitions similar to the experimentally observed values. The Pd3 complex with pentafluorophenyl groups was able to generate efficient singlet oxygen in polar solvents. Also, Pd3 was used to catalyse the photo-oxidation of aromatic aldehydes in good yields (51–93%) in the presence of a white LED. [ABSTRACT FROM AUTHOR]