Naphthyl anion

Now the interesting question arose of whether the intermediate analogous to 215 but devoid of the methyl groups, that is, 3d2-l H-naphthalene (221), would also be interceptable, because 221 should show a high thermodynamic acidity owing to its conversion into the 2-naphthyl anion (224) on deprotonation and because of the use of the strong base KOtBu for the liberation of 221 from 3-bromo-l, 2-dihydro-naphthalene (220) (Scheme 6.52). In the event, the major product was indeed naphthalene. However, there were further products, namely the enol ether 223 and small quantities of 2,2 -binaphthyl (228) as well as 1,2-dihydronaphthalene (226). The overall yield amounted to 92% [137]. 

An interesting example of intramolecular conversion of living polymer into a dormant one was observed on addition of styrene to living poly-l-vinyl naphthalene. The first molecule of styrene added to the terminal -CH(Naphthyl) anion yields a benzyl carbanion intramolecularly associated with the preceding naphthyl group. 

Ethynediide, ethynediyl dianion (traditional name acetylide) Naphthalene-2-ide, 2-Naphthyl anion... 

Meyers has demonstrated that chiral oxazolines derived from valine or rert-leucine are also effective auxiliaries for asymmetric additions to naphthalene. These chiral oxazolines (39 and 40) are more readily available than the methoxymethyl substituted compounds (3) described above but provide comparable yields and stereoselectivities in the tandem alkylation reactions. For example, addition of -butyllithium to naphthyl oxazoline 39 followed by treatment of the resulting anion with iodomethane afforded 41 in 99% yield as a 99 1 mixture of diastereomers. The identical transformation of valine derived substrate 40 led to a 97% yield of 42 with 94% de. As described above, sequential treatment of the oxazoline products 41 and 42 with MeOTf, NaBKi and aqueous oxalic acid afforded aldehydes 43 in > 98% ee and 90% ee, respectively. These experiments demonstrate that a chelating (methoxymethyl) group is not necessary for reactions to proceed with high asymmetric induction. 

The reaction course has not been elucidated (cf. also sodium hydroxide reagent). Hydrolyzation reactions and aromatizations are probably primarily responsible for the formation of colored and fluorescent derivatives. Substituted nitrophenols - e.g. the thiophosphate insecticides — can probably be hydrolyzed to yellow-colored nitro-phenolate anions by sodium hydroxide or possibly react to yield yellow Meisenheimer complexes. Naphthol derivatives with a tendency to form radicals, e.g. 2-naphthyl benzoate, react with hydrolysis to yield violet-colored mesomerically stabilized 1,2-naph-thalenediol radicals. 

Isobutene is unaffected by metallic sodium [18], by sodamide in liquid ammonia [19] and by naphthyl sodium in tetrahydrofuran [20]. This means either that anions or radical anions are not formed from isobutene, or that, if they are formed, they do not react with monomer. 

The difference in the electron affinity between light and heavy isotopic isomers is, in other words, the difference in the stability of their anion-radicals. Such a difference gives a valuable tool for use in probing the chemistry of anion-radicals. The difference in the stability of the ring-deuterated and ring-nondeuterated arene anion-radicals has been employed to examine the transition states for the one-electron-promoted cleavage of naphthyl methyl phenyl ether and naphthyl benzyl ether (Guthrie and Shi 1990). In this reaction, the potassium salt of fluoranthene anion-radical was an electron donor ... 

The reaction in Scheme 5.2 proceeds through the formation of the 1-bromonaphthalene anion-radical, which rapidly converts into the naphthyl radical. Thiophenolate intercepts the naphthyl radical and forms the anion-radical of l-(phenylthio)naphthalene. The reaction takes place in the preelectrode space. It competes with the formation of the unsubstituted naphthalene. The debromi-nation is a result of hydrogen abstraction from the solvent SolH by the naphthyl radical. The unreacted 1-bromonapthalene oxidizes the l-(phenylthio)naphthalene anion-radical formed. This leads to the neutral l-(phenylthio)naphthalene and the anion-radical of 1-bromonaphthalene. The reaction takes place in the bulk solution and is the key-point for the chain propagation. 

Miscellaneous The treatment of allyl 1-bromo-2-naphthyl ether 43 with f-BuLi affords benzyl alcohol 44 via a sequential reaction consisting of bromine-lithium exchange, and anion translocation, followed by a [1,2]-Wittig rearrangement (equation 23). ... 

Aryl radical additions to anions are generally very fast, with many reactions occurring at or near the diffusion limit. For example, competition studies involving mixtures of nucleophiles competing for the phenyl radical showed that the relative reactivities were within a factor of 10, suggesting encounter control,and absolute rate constants for additions of cyanophenyl and 1-naphthyl radicals to thiophenox-ide, diethyl phosphite anion, and the enolate of acetone are within an order of magnitude of the diffusional rate constant. ... 

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