Cross-coupling silver® nitrate

Oxidative cross-coupling reactions of alkylated derivatives of activated CH compounds, such as malonic esters, acetylacetone, cyanoacetates, and certain ketones, with nitroalkanes promoted by silver nitrate or iodine lead to the formation of the nitroalkylated products.67 This is an alternative way of performing SRN1 reactions using a-halo-nitroalkanes. 

Intermolecular dimerization has also been effected by a comparable protocol.24-26 Treatment of triethylborane with silver nitrate and sodium hydroxide in water at 25°C led to the rapid evolution of M-butane (72%), ethylene (9%), and ethane (9%). Reaction of two different alkylboranes led to statistical mixtures of dimerized and cross-coupled products. Furthermore, this strategy has been used successfully in the synthesis of olefins from dihydroborated internal acetylenes,27 and in polymerizations of bifunctional organoboron compounds.28... 

An RTF assay consists generally of four steps that are shown schematically in Figure 9. The purpose of the heavy-atom perturber is to encourage population of the triplet state via spin orbit coupling and intersystem crossing. The use of silver ion, as silver nitrate, is very eflFective in bringing this about and thereby enhancing the phosphorescence emission of many adsorbed PNA compounds. 

Heteroaryl phosphonates are common motifs in biological compounds and have stimulated the development of transition metal-catalyzed methodologies for C-P bond formation [68]. Phosphonated thiophenes 43 are accessible via silver-catalyzed dehydrogenative cross-coupling of thiophene 1 with dialkyl phosphites 42 (Scheme 19) [69]. The reaction is performed in aqueous dichloromethane, proceeds regioselectively at the a-position, and utilizes silver(l) nitrate as catalyst and the oxidant potassium persulfate. 

Complimentary reaction conditions were also developed with silver(l) nitrate that only necessitated 5 mol % of catalyst however, an additional 3 equiv of potassium fluoride was also required. The silver salts also suppressed homocoupling side reactions to favor the desired cross-coupled products. 

A dehydrogenative cross-coupling between pyridines or five-membered heteroarenes with secondary phosphites has recently been developed (Schemes 4.251 and 4.252) [406]. The approach used silver nitrate as the promoter and K S Og as an oxidant. When the... 

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