1,8-diiodonaphthalene

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Nickel(II) acetylacetonate has affected other cross-coupling reactions, however. Mitchell and Yan, Can. J. Chem., 58, 2584 (1980), reported yields of 35-60%, 3,3"-dichloro-2,2"-dimethyl-o-terphenyl in the cross-coupling of 3-chloro-2-methylphenylmagnesium chloride with o-dibromobenzene in tetrahydrofuran using equivalent amounts of the reactants and 6 mole percent nickel(II) acetylacetonate based on the Grignard reagent. Ibuki, et al., Bull. Chem. Soc. Japan, 53, 821 (1980), reported cross-coupling two-fold excess phenylmagnesium bromide with 2-iodobiphenyl in the presence of 1.0% nickel(II) acetylacetonate based on the limiting reagent, obtaining a 78-80% yield of o-terphenyl. Clough, et al., J. Org. Chem., 41, 2256 (1976), reported cross-coupling an eight-fold excess of phenylmagnesium iodide with 1,8-diiodonaphthalene using 0.9 mole percent nickel(II) acetylacetonate based on the limiting reagent, producing 1,8-diphenylnaphthalene in 70% yield, while Corriu and Masse, J. Chem. Soc. Chem. Comm., 144 (1972), reported yields of 40 to more than 80% in cross-coupling reactions utilizing 0.1-1 percent nickel(II) acetylacetonate with respect to Grignard reagent.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,8-diiodonaphthalene, (1.70 g, 4.5 mmol), 2-methyl-4-methoxyphenylboronic acid, 2, (2.20 g, 13.4 mmol), Pd(PPh3)4 (0.78 g, 0.67 mmol) and K3PO4, (4.30 g, 20.1 mmol) in 50 mL toluene was stirred at 100° C. for 18 hours. The resulting mixture was allowed to come to room temperature, quenched with water and extracted with CH2Cl2. The combined organic layers were dried over MgSO4 and concentrated in vacuo. Purification by flash chromatography on silica gel (CH2Cl2:hexanes 2:3) afforded 1.65 g (4.5 mmol, >99%) of off-white crystals containing syn- and anti-isomers of 7 in a ratio of 1:3. to come to room temperature quenched with water extracted with CH2Cl2 The combined organic layers were dried over MgSO4 concentrated in vacuo Purification by flash chromatography on silica gel (CH2Cl2:hexanes 2:3)