Adamantanes, oxygenation

The condensation reactions described above are unique in yet another sense. The conversion of an amine, a basic residue, to a neutral imide occurs with the simultaneous creation of a carboxylic acid nearby. In one synthetic event, an amine acts as the template and is converted into a structure that is the complement of an amine in size, shape and functionality. In this manner the triacid 15 shows high selectivity toward the parent triamine in binding experiments. Complementarity in binding is self-evident. Cyclodextrins for example, provide a hydrophobic inner surface complementary to structures such as benzenes, adamantanes and ferrocenes having appropriate shapes and sizes 12) (cf. 1). Complementary functionality has been harder to arrange in macrocycles the lone pairs of the oxygens of crown ethers and the 7t-surfaces of the cyclo-phanes are relatively inert13). Catalytically useful functionality such as carboxylic acids and their derivatives are available for the first time within these new molecular clefts. 

Oxygen-centered phosphanides are accessible by hydrolysis of the phospha-nides as shown for the oxygen-centered phosphanide 73 of the formula [Sr40- P(SiMe2Prl)2 6] with an Sr4P6 adamantane-like structure as shown in Eq. (7) [74], The strontium atoms are coordinatively saturated by agostic interactions to the silicon-bonded alkyl substituents. 

Kinetics of the dimethyidioxirane oxidation of adamantane in an oxygen atmosphere support a radicai mechanism. The kinetics of the oxidation of 2-methyibutane by DMDO in acetone soiution have been studied and the mechanisms of the reaction and of inhibition of the reaction by O2 were discussed. 

A further use of the system is to mediate the reaction of adamantane with carbon monoxide and oxygen to form 1-adamantanecarboxylic acid . When long-wavelength light (>300 nm) is used, hydroperoxides efficiently generate hydroxyl radicals without the use of metal ions and would be an extremely useful source of hydroxyl radicals, particularly in the design of DNA-cleaving molecules . ... 

BTSP-CF3SO3H is an efficient electrophilic oxygenating agent for adamantane and diamantane. With adamantane, the major reaction product is 4-oxahomoadamantane in isolated yield in 79% through a C—C a-bond insertion with very little 1-adamantanol, the C—H insertion product (equations 57 and 58/. In the case of diamantane, two isomeric oxahomodiamantanes were obtained along with two isomeric bridgehead diamantanols corresponding to C—C and C—H a-bond insertions. 

Bis(trimethylsilyl)peroxide-triflic acid was also found to be an efficient electrophilic oxygenating agent.209 Adamantane gives 4-oxahomoadamantane obtained through C—C a-bond insertion ... 

The adamantane work was undertaken as a contribution to the artificial fluorocarbon blood substitute area. The use of fluorocarbons as artificial blood and as oxygen carriers in other applications is an area that is being developed by Leland Gark, Jr., of Cincinnati Children s Hospital and Paul Geyer of Peter Bent Brigham Hospital in Boston. The reader who is unfamiliar with this area of research will find reviews on the subject to be extremely interesting (68). The... 

The unique hydride abstraction property has been gainfully employed in developing novel synthetic reactions.530 Reactive hydrocarbons such as triphenylmethane, adamantane, and diamantane are readily fluorinated in the presence of nitrosonium ion in HF-pyridine media.537 In the presence of a suitable oxygen donor such as dimethyl sulfoxide, the nitrosonium ion can act as a nitrating agent538 [Eq. (4.152)]. The initially formed nitrito onium ion 223 transfer nitrates aromatics rather readily.245 The NO+-induced reactions are further reviewed in Chapter 5. 

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