Grignard reagents with naphthalene

A most remarkable reaction of Grignard reagents with a l-(oxazolidin-2-yl)naphthalene has been described, in which addition to the aromatic ring occurs, whereas organolithium, organocerium or organocopper reagents all attack the oxazolidine 2-position [20] ... 

Chiral binaphthyls. Chiral binaphthyls can be prepared by reaction of an a-naphthyl Grignard reagent with the chiral 1-methoxy-2-oxazolinyl naphthalene 2. The adduct (3) is converted in two steps to a chiral binaphthyl alcohol (4).2... 

Harrowfield and coworkers have shown that ball-milling technique can be used to produce Grignard reagents with at least comparable efficiency to conventional solution methods [53], Reactions of 1-chloro- and 1-bromo-naphthalene with an excess of magnesium (4 1 ratio) in a Spex 8000 vibratory mill (10 x 12.7 mm stainless steel balls) proceed smoothly (Scheme 2.61). 

Carbanions ia the form of phenyllithium, sodium naphthalene complex, sodium acetyHde, or aromatic Grignard reagents react with alkyl sulfates to give a C-alkyl product (30—33). Grignard reagents require two moles of dimethyl sulfate for complete reaction. 

IV-substituted and B-substituted borazines are readily prepared by suitable choice of amine and borane starting materials or by subsequent reaction of other borazines with Grignard reagents, etc. Thermolysis of monocyclic borazines leads to polymeric materials and to polyborazine analogues of naphthalene, biphenyl, etc. ... 

The reaction has been applied to nonheterocyclic aromatic compounds Benzene, naphthalene, and phenanthrene have been alkylated with alkyllithium reagents, though the usual reaction with these reagents is 12-20, and Grignard reagents have been used to alkylate naphthalene. The addition-elimination mechanism apparently applies in these cases too. A protected form of benzaldehyde (protected as the benzyl imine) has been similarly alkylated at the ortho position with butyl-lithium. ... 

Under forcing conditions, Grignard reagents add to certain aromatic compounds. For example, the addition of PhMgBr to naphthalene takes place at 200 °C (Scheme 83) °. After treatment of the crude product with chloranil (for dehydrogenation), 1-phenylnaph-thalene is obtained in 34% yield. 

Grignard reagent.80 Competition by nucleophilic aromatic substitution was not observed unless the only active position(s) was (were) substituted with a leaving group, as in the reaction of l-methoxy-2-nitro-naphthalene which gave 1 -alkyl-2-nitronaphthalenes in 73-95% yields.81 The use of Me3SiCH2MgCl (Peterson reagent) provides an entry to nitro-substituted benzyl anion intermediates, as shown in the example of Scheme 9.82... 

Highly reactive powder (5, 419 7, 218). An improved procedure uses lithium together with an electron carrier (naphthalene or biphenyl, 10% based on Li) in THF, which need not be removed before preparation of Grignard reagents or other reagents.1... 

Another way in which l,4-epoxy-l,4-dihydronaphthalenes can react is via the deoxygenation reaction to form naphthalenes. For example, as shown in Equation (156), when 265 was allowed to react with 10 equiv of a commercially available Grignard reagent in refluxing THF, naphthalene 266 was obtained <1997TL4761>. 

Grignard reagent (see Chapter 10), followed by dehydration and arom-atization (Scheme 12.2). The use of substituted benzenes in the first stage of the sequence enables variously substituted derivatives of naphthalene to be obtained. Of course, the substituents should not interfere with the Friedel-Crafts reaction with succinic anhydride. 

There are two major routes to phenanthrene, both of which can be used to prepare substituted derivatives. In the Haworth synthesis (Scheme 12.11), reaction of naphthalene with succinic anhydride yields an oxobut-anoic acid which is reduced under Clemmensen conditions to the butanoic acid. Cyclization in sulfuric acid and reduction of the resulting ketone is followed by dehydrogenation over palladium-on-carbon to phenanthrene. Alkyl or aryl derivatives can be obtained by treatment of the intermediate ketone with a Grignard reagent prior to dehydration and oxidation. 

The Grignard reagent is prepared in normal manner [Orgf. Syntheses Coll. Vol. 1, 226 (1941)] from 50 g. (0.24 mole) of 1-bromo-naphthalene in 75 ml. of ether and 75 ml. of benzene. To this is added 23.4 g. (0.20 naole) of o-tolunitrile [Org. Syntheses Coll. Vol. 1, 514 (1941)], and the mixture refluxed for 8 hours followed by addition of ice and 100 ml. of concentrated hydrochloric acid. The precipitated solid is removed by filtration and boiled with water for 1 hour. The solid precipitated upon cooling is distilled to give 37.8 g. (76%) of 1-naphthyl o-tolyl ketone, b.p. 174 /0.4 mm., m.p. 59-61 . 

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