Radical carbonitrosation and recycling of the waste gas nitrogen monoxide

Visible-Light-Driven Iron-Catalyzed Decarboxylative C-N Coupling Reaction of Alkyl Carboxylic Acids with NaNO2

An efficient visible-light-driven iron-catalyzed decarboxylative C-N coupling reaction of alkyl carboxylic acids with NaNO2 under mild conditions was developed. The reaction proceeds under photosensitizer-free conditions and features good to excellent yields, broad functional group tolerance, and an easy operation procedure. Preliminary mechanistic investigations showed that visible-light-driven iron catalysis not only achieved oxidative decarboxylation of alkyl carboxylic acids to alkyl radicals but also promoted the reduction of NO2- to NO, thus leading to the C-N radical coupling reaction.

Cleavage of Organosolv Lignin to Phenols Using Nitrogen Monoxide and Hydrazine

From the variety of methods known for the depolymerization of organosolv lignin, a broad range of diversely substituted aromatic compounds are available today. In the present work, a novel two-step reaction sequence is reported, which is focused on the formation of phenols. While the first step of the depolymerization strategy comprises the 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-catalyzed oxidation of organosolv lignin with nitrogen monoxide so that two waste materials are combined, cleavage to the phenolic target compounds is achieved in the second step employing hydrazine and potassium hydroxide under Wolff-Kishner-type conditions. Besides the fact that the novel strategy proceeds via an untypical form of oxidized organosolv lignin, the two-step sequence is further able to provide phenols as cleavage products, which bear no substituent at the 4-position.

Nitrogen Oxides and Nitric Acid Enable the Sustainable Hydroxylation and Nitrohydroxylation of Benzenes under Visible Light Irradiation

A new type of waste recycling strategy is described in which nitrogen oxides or nitric acid are directly employed in photocatalyzed hydroxylations and nitrohydroxylations of benzenes. Through these transformations, otherwise costly denitrification can be combined with the synthesis of valuable compounds for various applications.

Sustainable Synthesis of Balsalazide and Sulfasalazine Based on Diazotization with Low Concentrations of Nitrogen Dioxide in Air

Low concentrations of nitrogen dioxide, which arises as a side product from a range of industrial processes, can effectively be recycled through the diazotization of anilines. The studies reported herein now demonstrate that the removal of nitrogen dioxide from gas streams is even more effective when hydrophilic anilines are used as starting materials. The diazonium salts, which are obtained in this way in up to quantitative yields, can directly be employed in azo coupling reactions, thus opening up an attractive route to the industrially important group of azo compounds.

Oxidative Nitration of Styrenes for the Recycling of Low-Concentrated Nitrogen Dioxide in Air

The oxidative nitration of styrenes in ethyl acetate represents a metal-free, environmentally friendly, and sustainable technique to recover even low concentrations of NO2 in air. Favorable features are that the product mixture comprising nitroalcohols, nitroketones, and nitro nitrates simplifies at lower concentrations of NO2 . Experiments in a miniplant-type 10 L wet scrubber demonstrated that the recycling technique is well applicable on larger scales at which initial NO2 concentrations of >10 000 ppm were reliably reduced to less than 40 ppm.

Pentakis(trifluoromethyl)benzenediazonium Cation: A Useful Building Block for the Syntheis of Trifluoromethyl-Substituted Derivatives

The sterically crowded, highly electron-deficient diazonium salt C₆ (CF₃ )₅ N₂ ⁺ BF₄ ^- has been synthesized and sample dediazotization reactions were carried out. New compounds, C₆ (CF₃ )₅ I, C₆ (CF₃ )₅ NO₂ , and C₆ (CF₃ )₅ NO were isolated and identified. Also, a more convenient route to C₆ (CF₃ )₅ NH₂ that gave good yield was achieved.