52917-72-3

Upstream product

• 281-23-2 adamantane 
• 118-75-2 chloranil 
• 75-05-8 acetonitrile 
• 196403-36-8 N-nitroso-N-(2-adamantyl)-O-benzylhydroxylamine 

Relevant academic research and scientific papers

The photochemical approach to the functionalization of open-chain and cyclic alkanes: 2. Hydrogen abstraction

Chloranil (Chl) has been irradiated in the presence of the alkanes 2,3-dimethylbutane, cyclohexane, norbornane, adamantane in acetonitrile. The primary step is hydrogen abstraction by triplet Chl, k(H) 0.8 to 2 x 106 M-1s-1, as confirmed by the detection of the ChlH. radical. Hydrogen abstraction from the alkanes is unselective. The thus formed alkyl radicals undergo different reaction, viz: coupling with ChlH· (both C-O coupling to give hydroquinonemonoethers and C-C coupling to give hydroxydihydrobenzofurans are observed); addition to ground state Chl to yield ultimately alkoxyphenoxyquinones; oxidation by groud state Chl (this process is fast only with tertiary radicals, and the cations formed in this case are trapped by the solvent MeCN to yield acetamides). Different methods for alkane functionalization are compared.

N-nitroso-N,O-dialkylhydroxylamines: Preparation, structure, and mechanism of the hydronium ion catalysed solvolytic nitrous oxide extrusion reaction

Eleven N-nitroso-N,O-dialkylhydroxylamines, RN(NO)OR′, have been prepared and the mechanisms of their hydronium ion catalysed solvolyses in aqueous solution which liberate nitrous oxide have been investigated. All reactions are first-order in substrate and first-order in hydronium ion, and the second-order rate constants at 25°C vary over a range of less than 140 in spite of considerable variation in substrate structure (R ranges from methyl to 4-methoxybenzyl to 2-adamantyl, for example) and changes in solvent composition (water with up to 50% methanol or 66% acetonitrile). Enthalpies and entropies of activation are qualitatively similar throughout the range (ΔH?= 72-93 kJ mol-1 and ΔS? = -19 to -57 J K-1 mol-1) which, with the product analyses, are accommodated by a mechanism involving pre-equilibrium protonation of the substrates followed by rate-limiting dissociation to give RN2O+ and HOR′. The oxodiazonium ion intermediate, RN2O+, then dissociates further to give the carbenium ion intermediate, R+, or suffers direct nucleophilic displacement of N2O by solvent (the external nucleophile) or by R′OH (the internal nucleophile liberated in the initial fragmentation). The carbenium ion, R+ (if formed), suffers nucleophilic capture either by solvent or by R′OH. When acetonitrile is the co-solvent (rather than methanol) for the N-(2-adamantyl) substrate 3g, the product of the Ritter reaction, 2-acetamidoadamantane, is detected. These nitrous oxide liberating reactions are compared with the nitric oxide liberating reactions of related N-nitrosohydroxylamines, and the origin of the difference between them is identified. The N(1)-nitroso group in the N,O-dibenzyl compound 3c is shown by X-ray crystallography to be essentially coplanar with the C and O atoms also bonded to N(1).

Oxidative functionalization of adamantane and some of its derivatives in solution

1,2,4,5-Benzenetetracarbonitrile (TCB) is irradiated in the presence of adamantane (1) and some of its derivatives. The singlet excited state of TCB is a strong oxidant, and there is various evidence, including time-resolved spectroscopy, to prove that SET from the alkane to TCB1* takes place and yields the corresponding radical ions. The adamantane radical cation deprotonates from the bridgehead position, and the resulting radical couples with TCB-*. Deprotonation via the radical cation occurs with a number of substituted adamantanes and remains the exclusive or predominating reaction also with derivatives containing a potential electrofugal group, such as one of the following carbocations: t-Bu, CH2OMe, CH2OH (notable here is that C-H deprotonation is more efficient than O-H deprotonation). A carboxy group is lost more efficiently than a proton, however. In contrast, detaching of such cations is the main process when the radical cations of substituted adamantanes is produced anodically. This different behavior is explained on the basis of thermochemical calculation and of the different environments experienced by the radical cation in the two cases, viz reaction from the solvated radical cation in the first case and from the substrate adsorbed on the anode in the latter one. 1-Methoxyadamantane deprotonates from the methyl group, a reaction explained by the different structure of the radical cation. On the other hand, the radical NO3*, conveniently produced by photolysis of cerium(IV) ammonium nitrate, reacts by hydrogen abstraction with selective attack at the bridgehead position and little interference by substituents and thus offers a useful way for the selective oxidative functionalization of adamantanes.

Photoinduced SET for the Functionalization of Alkanes

Thermochemical cycles show that deprotonation of alkane radical cations is an exothermic process, and indeed photoinduced SET between several alkanes and 1,2,4,5-tetracyanobenzene (TCB) is followed by efficient deprotonation of the radical cation with tertiary > secondary > primary selectivity; the alkyl radical is trapped by TCB.- or, when present, by oxygen; when tetrachloro-p-benzoquinone is used in the place of TCB, the radical is further oxidized to the cation.

PHOTOCHEMICAL OXIDATION AND AUTOXIDATION OF SOME CYCLOALKANES PROMOTED BY CERIC AMMONIUM NITRATE IN ACETONITRILE

The oxidation and autoxidation of adamantane, norbornane and cyclohexane can be photochemically promoted by ceric ammonium nitrate in acetonitrile at room temperature, both processes being extremely efficient and selective with adamantane.