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Herein, we report visible-light induced C–O bond cleavage of vinyl-appended cyclic synthons via a Co(II)-photoredox dual catalytic approach operating at room temperature. This methodology exhibits a broad scope and is capable of accessing linear as well as branched allyl arenes simply by tuning the ring size of the cyclic motifs, in a mild and environmentally friendly protocol. Mechanistic studies unveil an interesting aspect of the reaction pathway involving a challenging homolytic cleavage of the Co(III)–O bond, 1,5-HAT of an unstable Co(II)-organometallic intermediate, and the key roles of O2 and the photocatalyst. The successful removal of the directing group further adds an important dimension to the methodology. [ABSTRACT FROM AUTHOR]

This article provides a comprehensive overview of the synthesis and modification of organic fluorophores, which are organic compounds that emit light when excited. It discusses various synthetic reactions used to create these fluorescent molecules, with a focus on transition-metal-catalyzed C–H activation reactions. The article categorizes recent C–H activation reactions and evaluates their advantages and limitations. This information is valuable for researchers and readers interested in the field of organic fluorophores. The document also includes biographical information about the authors, Dr. Tapasi Chand and Dr. Manmohan Kapur. [Extracted from the article]

Reported herein is an efficient and eco-friendly peri-selective monohydroxylation of naphthalene monoimides (NMIs) to access 4-hydroxy NMIs, which possess multidisciplinary applications. The key aspect of this method is the utilization of cobalt(II)-catalysis via a single electron transfer mechanism to achieve site-selective C(sp2)-hydroxylation. Transformation of the hydroxyl group into pseudohalides reveals its applications towards cross-coupling reactions. [ABSTRACT FROM AUTHOR]

Herein, we report an efficient synthetic strategy for an Fe(ii)-catalyzed site-selective ring opening of bicyclo[n.1.0]alkanols and their concomitant 1,6-conjugate addition to p-quinone methides. Access to tertiary carbon centers with appendaged carbocycles of distinct sizes and functional groups are achieved, under a substrate-controlled bond scission of the fused cyclopropanols. Synthetic derivatizations further enhance the utility of the protocol. [ABSTRACT FROM AUTHOR]

A site‐selective C(3)/C(4)‐alkylation of N‐pyridylisoquinolones is achieved by employing C−C bond activation of cyclopropanols under Ru(II)‐catalyzed/Cu(II)‐mediated conditions. The regioisomeric ratios of the products follow directly from the electronic nature of the cyclopropanols and isoquinolones used, with electron‐withdrawing groups yielding predominantly the C(3)‐alkylated products, whereas the electron‐donating groups primarily generate the C(4)‐alkylated isomers. Density functional theory calculations and detailed mechanistic investigations suggest the simultaneous existence of the singlet and triplet pathways for the C(3)‐ and C(4)‐product formation. Further transformations of the products evolve the utility of the methodology thereby yielding scaffolds of synthetic relevance. [ABSTRACT FROM AUTHOR]

Reported herein is a reactivity of propargyl alcohols as "Three‐Carbon Synthons" in a Rh(III)‐catalyzed C−H functionalization of acetanilides, leading to the synthesis of core structures of isocryptolepine, γ‐carbolines, dihydrochromeno[2,3‐b]indoles, and diindolylmethanes (DIM) derivatives. The transformation involves a rhodium(III)‐catalyzed C−H functionalization and heteroannulation to yield indoles followed by a cascade cyclization with both external and internal nucleophiles to afford diverse products. The role of the hydroxy group, the key function of the silver additive, the origin of the reverse regioselectivity and the rate‐determining step, are rationalized in conformity with the combination of experimental, noncovalent interaction analysis and DFT studies. This protocol is endowed with several salient features, including one‐pot multistep cascade approach, exclusive regioselectivity, good functional group tolerance and synthesis of variety of molecular frameworks. [ABSTRACT FROM AUTHOR]

The total synthesis of the 14‐membered resorcylic acid lactone neocosmosin A is described. The key step in the synthesis is the palladium‐catalyzed α‐arylation of TES‐enol ethers of enones. The employment of the α‐arylation approach to this class of resorcylic acid lactones is a new approach, which has the scope of being generalized into a unified approach for the synthesis of this class of natural products. [ABSTRACT FROM AUTHOR]

The dominant fungal-growth-promoting substance produced by the mycorrhiza helper bacterium Streptomyces strain AcH 505, auxofuran, is isolated and its effect on the levels of gene expression of Amanita muscaria is investigated. The characterization has provided the foundation for molecular analysis of the fungus-bacterium interaction in the ectomycorrhizal symbiosis between fly agaric and spruce.

A tremendous upsurge has been seen in the recent decade for the proximal and remote functionalization of activated and unactivated substrates via palladium redox pathways. This feature article discusses some of the recent reports on direct as well as indirect C(sp3)–H functionalization via cross-coupling reactions under palladium catalysis. Activated substrates (possessing acidic C(sp3)–H) including enones, ketones, aldehydes, silylenol ethers, esters, silyl ketene acetals, amides, cyano, α-amino esters, and O-carbamates, capable of undergoing cross-coupling reactions at the α-, β-, γ-, δ- and ε-positions, will be discussed. To overcome the challenging task of achieving regioselectivity, a variety of innovative modifications have been reported. The reports of C–H activations based on directing group, and as native functionality have been illustrated at the β-, γ- and δ-positions. Substrates such as α-amino esters, carbonyls, carboxylic acids and their derivatives, afford site-selective C(sp3)–H functionalization via varied-sized reactive metallacycles and are a unique class of substrates whose C(sp3)–H functionalizations were earlier considered as very difficult. [ABSTRACT FROM AUTHOR]

A unique approach to achieve site‐selective C−H olefinations exclusively at the C‐3‐ or C‐8‐positions in the quinoline framework has been developed by catalyst control. Distal C(3)−H functionalization is achieved by using palladium catalysis, whereas proximal C(8)−H functionalization is obtained by employing ruthenium catalysis. Switching the site selectivity within a single substrate directly indicates two diverse pathways, which are operating under the palladium‐ and ruthenium‐catalyzed reaction conditions. [ABSTRACT FROM AUTHOR]