Tetrakis naphthalene

Several examples of carbenoid ion-radicals are discussed within this book. A silylene anion-radical preparation and properties is exemplified here. Scheme 2.5 shows the path to this species. Tetrakis(di-tert-butytmethylsilyl)disilylene was reduced by lithium or sodium salt of naphthalene anion-radical in THF at 78°C and then 12-crown-4 was added to the resulting reaction mixture. The silylene anion-radical was obtained as the corresponding alkali salt. Red crystals of the salt were isolated and characterized by ESR spectroscopy and x-ray crystallography (Inoue et al. 2007). 

B2C14 can add to dienes (1,3-butadiene, 1,3- and 1,4-cyclohexadienes) to yield either mono- or diadducts depending on the reagent reactant ratio.474-477 1,3-Cyclohexadiene, for example, forms the unstable l,2,3,4-tetrakis(dichloroboryl)cy-clohexane with high selectivity when it reacts with a threefold excess of B2C14.476 Naphthalene yields a similar diadduct.476 477... 

The observations101 that l,2-bis(TMS)-l,2-dihydro-naphthalene (141)101,102 reacts with further chlorotrimethylsilane (142) to afford tris- and tetrakis(TMS)-tetrahyd-ronaphthalenes (143,144a, b) and rearrangements101 were an early example of the so-called reductive silylation (Scheme 19). 

J. Lipkowski, Clathrate inclusion compounds of bis(isothiocyanato) tetrakis(4-methylpyridine) nickel (II). Part V naphthalene clathrate. Acta. Cryst. B38, 1745-1749 (1982)... 

The next step could be defluorination of the tetrakis(phenylthio)octa-lin. Double bonds thus formed change the system to a derivative of naphthalene, 2,3,6,7-tetrafluoro-l,4,5,8-tetrakis(phenylthio)naphthalene. If this happens, it is a very unusual reaction, because sodium thiophenolate is... 

Relatively little is known of the reactions of diboron tetrahalides with aromatics apart from a study by Fox and Wartik (39) of the interaction of B2CI4 with benzene and naphthalene. With the former, dichlorophenyl-borane was obtained in high yield after long reaction times. With naphthalene, immediate formation of a loose complex was suggested by the formation of a bright yellow color. The reagents could be recovered from this complex by distillation, but after about 2 weeks at room temperature a product formulated as l,2,3,4-tetrakis(dichloroboryl)tetralin (IX) was obtained. 

In this section, the derivatives of l,8-bis(dialkylamino)naphthalenes with at least one additional dialkylamino group will be covered. There exist two approaches to the synthesis of such compounds. The first consists of reduction and successive alkylation of the corresponding nitro- or polynitronaphthalenes. Until recently, this approach was successful only for the preparation of tris- and tetrakis(dialkylamino)naphthalenes. For the introduction of more dialkylamino groups, the nucleophilic substitution of fluorine atoms in octafluoronaphthalene is the method of choice. 

TABLE 3. Synthesis of tris- and tetrakis(dialkylamino)naphthalenes from (nitro)naphthylamines... 

Treatment of fluorinated polykis(dialkylamino)naphthalenes with small excess of LiAII I4 in boiling THF results in exhaustive hydrodefluorination. This route, starting from 71, 73 and 75, provides high yields of tetrakis(dimethylamino)naphthalene 7962 and proton sponges 80 and 8164. 

Similarly, non-separable two-electron transitions were also observed for proton sponges 65, 66 and tetraamine 13454,58. As seen from Table 13, compound 35 is the strongest electron donor among all known tetrakis(dimethylamino)naphthalenes. The oxidation of 65 with four mole equivalents of iodine at low temperature also led to the formation of a black-brown salt (/.max = 723 nm, lg e = 4.31) of the dication 13558. 

It follows from Tables 17 and 18 that tetrakis(dimethylamino)naphthalenes 35 and especially 65 possess higher basicity in comparison with parent compound 1. It was hoped that a further increase in the number of NMe2 groups would increase the basicity even higher. Unfortunately, the first representatives of such compounds, namely hexa- and heptakis(dialkylamino)naphthalenes (Section II.B.2), turned out to be scarcely soluble in MeCN, DMSO, EtOH and H2O. Yet, their pK, values were measured in 80% aqueous dioxane by a potentiometric titration technique166. The acid ionization constants are summarized in Table 19 together with the pXa values of tetrakis(dimethylamino)naphthalenes 35 and 65 determined under the same conditions. 

Three products, l,2,3,7-tetrakis(TMS)-l,2,3,4-tetrahydro-naphthalene 143), l,2,4-tris(TMS)-l,4-dihydro 144a)- and l,2,4-tris-(TMS)-l,2-dihydro-naphthalcne 144b) NGxt isolated ... 

A number of examples of the use of host-guest chemistry in the creation of PET active systems have appeared. The reaction of P-cyclodextrin alcoholate with meso-tetrakis(pentafluorophenyl)porphyrin is reported to give a hydrophilic cyclodextrin-porphyrin conjugate in 14% yield. ° In the presence of guests such as 1,4-benzoquinone, anthraquinone-2-sufonate or 8-anilino-l-naphthalene sulfonic acid, PET operates as evidenced by the fluorescence... 

In order to reduce the crystallinity of the polyketal an unsymmetrical cyclic diketone was prepared from 2,7-dihydroxy-naphthalene. Reduction of the naphthalene nucleus with Raney nickel and hydrogen gave a 90% yield of the 2,7-decalindiol, which on oxidation with chromic acid gave a 50% yield of the 2,7-deca-lindione. When this diketone was condensed with the tetrakis-(hydroxymethyl) cyclohexane, an 89% yield of a white polymer VIII was obtained which did not melt and was soluble only in hexa-fluo ro isopropano1. 

An established pathway to naphthylsilanes is the Grignard reaction which, in this case, requires fluorosilanes as silicon components, as can be shown by the synthesis of bis (l-naphthyl)difluorosilane (234) (equation 113a)131. However, for the synthesis of tetrakis (2-naphthyl)silane (235) it is preferable to use lithiated naphthalene (equation 113b)142. In... 

Staab, H.A., Kirsch, A., Barth, T. et al. (2000) New proton sponges , 14. Isomeric tetrakis (dimethylamino)naphthalenes syntheses, structure-dependence of basicities, crystal structures and physical properties. European Journal of Organic Chemistry, 1617-1622. 

Barth, T., Krieger, C., Neugebauer, RA. and Staab, H.A. (1991) 1,4,5,8-Tetrakis(dimethyla-mino)naphthalene synthesis, structure, proton sponge and electron donor properties. Ange-wandte Chemie — International Edition, 30, 1028-1030. 

A series of l-(isoquinolin-l-yl)naphthalen-2-amines 239 was prepared. The atropisomers of the NH2, N-Me and N,N-diMe2 derivatives were separated on various CSPs and the barriers to racemization in toluene were experimentally determined AG = 125.4, 130.8, and 124.5 kj mol respectively. Molecular mechanics calculation showed that the most favorable transition state is the anti one in which the amino group is opposite to the isoquinoline nitrogen (04H223). When racemic 239 (R = Me, = H) and zirconium tetrakis(dimethylamide) were combined in a 2 1 ratio. X-ray data of the complex showed that a selection of identical ligand antipodes by the metal had occurred (homochiral complex) (02AG(IE)345). 

Acetylene cooligomerization. Vollhardt has extended his synthesis of the strained 4,5-bis(trimethyIsilyl)benzocycIobutene (6, 153-154) to a synthesis of 2,3,6,7-tetrakis(trimethylsilyl)naphthalene (3) by reaction of the ether (1) with bis(trimethylsilyl)acetylene (2) using this homogeneous catalyst. The product is useful as an intermediate to various substituted naphthalenes. ... 

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