Bis-P-naphthol

Coupling in para or ortho positions is easily accomplished with phenols 912,1037,1095] and aromatic amines [915]. -Naphthol, on refluxing with anhydrous ferric chloride in ether, is converted in 60% yield into a,a -bi-p-naphthol [9i2], and 2,4-bis(rert-butyl)-5-methylphenol, on heating with chromic acid, yields the corresponding dimer [1095] (equation 44). 

Exposure of crystals of racemic bis-P-naphthol (Figure 8.11(a)) to p-henzo-quinone vapour or solid-state mixing with -benzoquinone does not provide a co-crystal. In contrast, mechanochemical grinding provides a co-crystal composed of finite hydrogen-bonded molecular assemblies (Figure 8.11(b)). 

Figure 8.11 (a) Molecular diagram of bis-P-naphthol, (b) and (c) finite and infinite... 

Takahashi M, Ogasawara K. An expedient route to some monoalkyl ethers of enantiomerically pure bi-P-naphthol. Tetrahedron Asymm. 1997 8 3125-3130. 

The reaction between epoxides and ammonia is a general and useful method for the preparation of P-hydroxyamines. " Ammonia gives largely the primary amine, but also some secondary and tertiary amines. The useful solvents, the ethanolamines, are prepared by this reaction. For another way of accomplishing this conversion, see 10-54. The reaction can be catalyzed with Yb(OTf)3 and in the presence of a-BINOL is l,l -bi-2-naphthol derivative gives amino alcohols with high asymmetric induction. A variation used Yb(OTf)3 at lOkbar or at ambient pressure. Lithium triflate can also be used. Primary and secondary amines give, respectively, secondary and tertiary amines, for example. 

This chiral column has been shown successfully to resolve enantiomeric mixtures (or racemates) of aromatic alcohols including l,l -bi-2-naphthol and its analogues (p. 836), aromatic hydroxy (or alkoxy) carboxylic esters and amides, amino acid derivatives, sulphoxides, cyclic imides and amides, lactones, etc. Even this list should not be regarded as limiting. The potential of this method, coupled with the simplicity of operation will undoubtedly be extensively developed and explored in the coming years. 

This compound, in common with other suitable substituted biphenyls, possesses a chiral axis (p. 6) and is isolated from the reaction as a racemate. Although several resolution procedures have been reported, the superior method to date4 is that in which the binaphthol is first converted by treatment with phosphorus oxychloride into the binaphthyl phosphoric acid (14). Resolution is then effected by formation of diastereoisomeric salts with (+ )-cinchonine, appropriate fractional crystallisation and recovery of the (S)-( + )-binaphthyl phosphoric acid. Suitable hydrolysis gives (S)-( — )-l,l -bi-2-naphthol (15). 

BENZENEAZODIMETHYKANILINE see DOT300 BENZENE-1-AZO-2-NAPHTHOL see PEJ500 BENZENEAZO-p-NAPHTHOL see PEJ500 l-BENZENEAZO-2-NAPHTHYLAiMlNE see FAG130 1-BENZENE-AZO-P-NAPHTHYLAMINE see FAG130 p-BENZENEAZOPHENOL see HJFOOO BENZENE, l,3-BIS(ISOCYANATOMETHYL)-(9CI) see XIJOOO... 

Very recently, Fan et al. [13] reported on the use of a water-soluble PEO-substitut-ed first- and second-generation Frechet-type dendrimer with a chiral BINOL (1,1 -bi-2-naphthol) unit in catalysis. The enantiomeric excess in asymmetric hydrogenation of 2-[p-(2-methylpropyl)phenyl]acrylic acid with [RuCl(BINAP)(cymene)]Cl in an aqueous system was reported to increase upon addition of the dendritic... 

Since ot-nitroso-p-naphthol (11 pK = 7.70) and p-nitroso-a-naphthol (p/C 7.22) are weaker acids than nitrosophenylhydroxylamine (16 p/C=4.15), complex formation and solvent extraction require more alkaline solutions. Tris complexes of Fe or Co are formally uncharged octahedral species extractable into light petroleum like the uncharged square planar complex of Pd . On the other hand the bis complexes of Fe , Ni and Co require two water molecules to complete their coordination sphere and though extractable into diethyl ether are insoluble in the non-polar ligroin. 

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