Amination of alkanes

Amination of alkanes (cyclohexane, heptane, adamantane) was achieved with iron and manganese porphyrin catalysts by tosylimidoiodobenzene to yield tosyl-amino derivatives.200 Selective 1-substitution of adamantane (56% yield) and 2-substitution of heptane (66% selectivity) were reported. 

In 2008, Diaz-Requejo, Perez, and coworkers developed a new silver-based catalytic system which proceeded the direct intermolecular amination of alkanes [33]. This new catalyzed system employed complexes [Tp Ag]2 8 as catalyst and Phl=NTs ([Ag]/[PhI=NTs]=l/20) as the nitrene source. The reaction was carried out in neat alkane at 80°C for 4 h. Linear and branched alkanes were converted to corresponding isomeric mixtures of amides in moderate to excellent yields (Scheme 12). The amination/amidation was favored at tertiary sites over secondary and primary sp C-H bonds of alkanes, and only a few examples were observed at primary sp C-H bonds. The reaction was inhibited when 2,6-di-tert-butyl-4-methylphenol (BHT) was present. Chloroalkanes were observed when CCI4 was used as solvent. These evidences indicated that the mechanism involved radical species. 

Muller then intensively studied rhodium dimer complexes as catalysts for the intermolecular amination of alkanes using iminoiodinanes, typically PhI=NTs and PhI=NNs [28-30]. Good yields were obtained for amination of benzyUc, aDylic and tertiary C—H bonds, which are the most reactive C— H bonds towards metal nitrenes. For instance the amination of indane provided the corresponding benzylic amine in... 

This chapter vhll focus only on the most recent aspect of rhodium nitrene chemistry to perform C—H amination of alkanes, which has not been covered in previous reviews. The literature has been surveyed from 2001 to September 2008. 

In 2012, Du Bois and Zare published details of a novel method to observe intermediates in the CH amination reactions catalyzed by dirhodium carboxylate complexes [88]. In this study, desorption electrospray ionization (DESl) was coupled to mass spectroscopy to capture transient intermediates from solution having very short lifetimes (ca. nanoseconds to microseconds). Rh2(esp)2 is a catalyst for the amination of alkanes, such as adamantane, as shown in Scheme 24. 

We have often seen that the polar nature of a substance can affect physical properties such as boiling point This is true for amines which are more polar than alkanes but less polar than alcohols For similarly constituted compounds alkylamines have boiling points higher than those of alkanes but lower than those of alcohols... 

Furthermore, the ultrasonic irradiation of alkanes in the presence of N2 (or NH or amines) gives emission from CN excited states, but not from N2 excited states. Emission from N2 excited states would have been expected if the MBSL originated from microdischarge, whereas CN emission is typically observed from thermal sources. When oxygen is present, emission from excited states of CO2, CH-, and OH- is observed, again similar to flame emission. 

Hydroperoxides have been obtained from the autoxidation of alkanes, aralkanes, alkenes, ketones, enols, hydrazones, aromatic amines, amides, ethers, acetals, alcohols, and organomineral compounds, eg, Grignard reagents (10,45). In autoxidations involving hydrazones, double-bond migration occurs with the formation of hydroperoxy—azo compounds via free-radical chain processes (10,59) (eq. 20). 

Table 18-L regularities in names of alkanes, alcohols, and amines...

In the same spirit DFT studies on peroxo-complexes in titanosilicalite-1 catalyst were performed [3]. This topic was selected since Ti-containing porous silicates exhibited excellent catalytic activities in the oxidation of various organic compounds in the presence of hydrogen peroxide under mild conditions. Catalytic reactions include epoxidation of alkenes, oxidation of alkanes, alcohols, amines, hydroxylation of aromatics, and ammoximation of ketones. The studies comprised detailed analysis of the activated adsorption of hydrogen peroxide with... 

All in aqueous solution at 25°C unless otherwise noted equilibrium constants have dimensions of M. Various alkane thiols, of similar equilibrium reactivity. Methylamine or a primary alkyl amine of similar reactivity. Dimethylamine or a secondary alkyl amine of similar reactivity °Reference 30. Reference 14. RSH is mercaptoethanol. Reference 31. Reference 32. Reference 33. Reference 21. RSH is ethanethiol " Reference 34. Reference 35. Reference 36. Reference 37. RSH is 2-methoxyethanethiol. Reference 38. Reference 39. Reference 40. Reference 23. Reference 41. Reference 31. Reference 42. Reference 5. Reference 43. In ethanol. Reference 44. Reference 45. Reference 46. RNKj is n-butylamine. "Reference 47. 

In contrast to the borylation of alkane C-H bonds, the coupling of aryl halides with amines was based on a literature precedent from another group published about a decade before our initial studies. Kosugi, Kameyama and Migita published the coupling of aryl halides with tin amides." Mechanistic studies we conducted on this process led us to the perhaps obvious realization that the reaction" could be conducted with amines and a silylamide base instead of tin amides (equation 4)." Surveys of bases with similar p a values led Janis Louie to conduct reactions with alkoxide bases. Similar studies were conducted at nearly the same time by Steve Buchwald and coworkers."... 

Trzilova, B., Horska, E. (1988) Biodegradation of amines and alkanes in aquatic environment. Biologia (Bratislava) 43, 209-218. Tse, G., Sandler, S.I. (1994) Determination of infinite dilution activity coefficients and 1-octanol/water partition coefficients of volatile organic pollutants. J. Chem. Eng. Data 39, 354—357. 

The oxidation of primary and secondary alcohols in the presence of 1-naphthylamine, 2-naphthylamine, or phenyl-1-naphthylamine is characterized by the high values of the inhibition coefficient / > 10 [1-7], Alkylperoxyl, a-ketoperoxyl radicals, and (3-hydroxyperoxyl radicals, like the peroxyl radicals derived from tertiary alcohols, appeared to be incapable of reducing the aminyl radicals formed from aromatic amines. For example, when the oxidation of tert-butanol is inhibited by 1-naphthylamine, the coefficient /is equal to 2, which coincides with the value found in the inhibited oxidation of alkanes [3], However, the addition of hydrogen peroxide to the tert-butanol getting oxidized helps to perform the cyclic chain termination mechanism (1-naphthylamine as the inhibitor, T = 393 K, cumyl peroxide as initiator, p02 = 98 kPa [8]). This is due to the participation of the formed hydroperoxyl radical in the chain termination ... 

Having successfully aminated the alkylzirconocene chloride, the reaction was extended to borazirconocene 1,1-alkanes. In fact, amination of gem-borazirconocene alkanes 18 with MSH has proven to be a facile process [119]. Thus, when MSH is added to the gem-bime-tallics in THF at ambient temperature, the amination is complete within 20 min (Scheme 7.16). 

In this section, you will learn how to predict the reactions of different functional groups. You studied the most common reaction of alkanes, combustion, in your previous chemistry course. For this reason, the reactions of alkanes will not be considered here. The reactions of amines and ethers will be left for a later chemistry course. 

---