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This article discusses recent developments in the photocatalytic reduction of nitro compounds to valuable intermediates, such as amines and azo compounds. Nitro compounds are widely used in various industries but pose environmental and health hazards due to their toxicity and nondegradability. Traditional reduction methods often use harsh conditions and toxic chemicals, making the utilization of photocatalytic organic transformations an attractive option for sustainable and green chemical processes. The article provides an overview of different photocatalytic systems, including metal-organic frameworks, semiconductors, and nanocomposites, and explores their synthesis, performance, stability, recyclability, and selectivity. The use of hole scavengers and sacrificial reagents to enhance the reduction process is also mentioned. The studies demonstrate the potential of these photocatalytic systems for efficient and environmentally friendly nitro compound reduction. [Extracted from the article]

In the presence of Na2 CO3 , conjugate addition of α-halo hydrazones to nitroso compounds proceeded readily to give polyfunctionalized nitrones in reasonable chemical yields and excellent stereoselectivities. The chemical structure and the stereochemical configuration of the products were unambiguously identified by an X-ray single-crystal structural analysis. [ABSTRACT FROM AUTHOR]

Recent progress in the nitroso-ene reaction indicates the potentially rich reactivity of the nitroso species. In this study, we highlight the synthetic efforts towards the construction of the aza-spirocyclic or aza-bridged ring embedded in biologically significant alkaloids via the proposed approach. Our endeavors along this direction are exemplified in the formal synthesis of (±)-cephalotaxine and the total synthesis of (-)-hosieine A. 1 Introduction 2 Aza-Spirocyclane: A Formal Synthesis of (±)-Cephalotaxine 3 Method Development 4 Aza-Bridge Ring: A Total Synthesis of (-)-Hosieine A 5 Epilogue [ABSTRACT FROM AUTHOR]

A new and versatile synthetic approach towards bis(pyrazolyl) methanes, based on 1,4-addition of pyrazoles to conjugated α-halogenated nitroso- and azoalkenes, is described. Tris(pyrazolyl) methanes can also be obtained by this methodology. [ABSTRACT FROM AUTHOR]

An unprecedented one-pot approach to 5-substituted dipyrromethanes based on the hetero-Diels-Alder reaction of azoand nitrosoalkenes is described. The on-water reaction conditions led to the target compounds in higher yields with significantly shorter reaction times and simpler purification procedures than carrying out the reaction in dichloromethane or in the absence of solvent. [ABSTRACT FROM AUTHOR]

Reaction of N-aryl-2-nitrosoanilines with alkyl arylidenecyanoacetates in the presence of Et3N in MeCN leads to substituted 1,2,3,4-tetrahydroquinoxaline derivatives in reasonable yields. The reaction comprises nucleophilic addition of the nitrosoaniline to the Michael acceptor followed by cyclization involving the nitroso group. Since the reactive nitrogen groups in N-aryl-2- nitrosoanilines are of opposite character the reaction is regioselective and additionally it was found to be diastereoselective. [ABSTRACT FROM AUTHOR]

N-Aryl-2-nitrosoanilines possessing 5-alkylamino groups undergo a bisheteroannulation reaction with anions of 2-cyanoalkanecarboxylates resulting in pyrroloquinoxalinone derivatives. The cascade reaction involves condensation of the cyanoester anions with the nitroso group, unusual nucleophilic substitution of hydrogen in the nitrosoaniline-derived intermediate with the second carbanion molecule, and double intramolecular acylation of the amino functions. [ABSTRACT FROM AUTHOR]

A general and efficient vanadium-catalyzed oxidation of tert-butyl N-hydroxycarbamate to tert-butyl nitrosoformate using alkyl hydroperoxides as terminal oxidants has been developed. The intermediate nitroso compound was trapped by in situ Diels–Alder reaction with simple and functionalized dienes, providing general access to a variety of functionalized 3,6-dihydro-2H-1,2-oxazines. [ABSTRACT FROM AUTHOR]

N-Aryl-2-nitrosoanilines, easily available from reaction of nitroarenes with anilide anions, undergo base-promoted condensation reaction with substituted benzyl aryl sulfones, furnishing 1,2-diaryl-1H-benzimidazoles. [ABSTRACT FROM AUTHOR]

An organocatalyzed enantioselective desymmetrization reaction for converting 3-substituted cyclobutanones into 4-substituted 5-hydroxy-γ-lactams is presented. This involves a ring-expanding O-nitroso aldol-cyclization domino sequence. This synthetic protocol provides access to five-membered ring systems in good yields with the generation of two new stereogenic centers. [ABSTRACT FROM AUTHOR]

Keggin-type heteropolyacids have been used as catalyst for high-yielding oxidation reactions in multiphase conditions. This simple and efficient procedure promoted the conversion of anilines to the corresponding nitroso and nitro derivatives. In comparison with homogeneous system the oxidation from anilines to nitroso compounds and nitro compounds were more effective and the solvents used were not toxic. [ABSTRACT FROM AUTHOR]

Keggin-type heteropolyacids have been used as catalyst for high-yielding oxidation reactions in multiphase conditions. This simple and efficient procedure promoted the conversion of anilines to the corresponding nitroso and nitro derivatives. In comparison with homogeneous system the oxidation from anilines to nitroso compounds and nitro compounds were more effective and the solvents used were not toxic. [ABSTRACT FROM AUTHOR]

The first enantioselective tandem conjugate addition/Nnitroso aldol reaction catalyzed by copper and phosphoramidite is presented. The reactions proceeded smoothly furnishing the a-hydroxyamino carbonyl compounds in good yields with high enantioselectivity up to 95% ee. [ABSTRACT FROM AUTHOR]

Enantioselective asymmetric N-nitroso aldol reaction of tertiary β-carbonyl esters using the bifunctional squaramide organanocatalysts is described. These adducts have been obtained in moderate yields and with up to 98% ee. [ABSTRACT FROM AUTHOR]

Asymmetric aminoxylations of a stoichiometric amount of ketones were accomplished through O-nitrosoaldol reactions of 2-nitrosotoluene catalyzed by a proline-based tetrazole. The advantages of 2-nitrosotoluene and the tetrazole over nitrosobenzene and proline, respectively, were demonstrated. [ABSTRACT FROM AUTHOR]

The article focuses on the selection of chiral brønsted acid in the organocatalytic α-aminoxylation reactions. According to professor Guofu Zhong, their research group has been interested to use nitroso compounds as terminal oxidants in the organocatalytic α-aminoxylation reactions. Zhong figured that by the selection of brønsted acid, selective protonation of the basic nitrogen of nitroso compounds will facilitate the nucleophilic attack at the oxygen atom.