4,4′-Bis(1,1-dimethylethyl)-1,1′-biphenyl

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General procedure: Arylboronic acid (0.3 mmol), CuCl2·2H2O (2.5 mg, 5 molpercent), Na2CO3 (10 molpercent), methanol (1 mL) were added to a vial. The reaction mixture was stirred at 25 °C inthe air for 5-15 min and was monitored by TLC. Then the reaction was quenched withtwo drops of H2O, diluted with 2 mL of ethyl acetate, and filtered over a pad ofMgSO4 and silica. The pad was rinsed with additional ethyl acetate, and the solutionwas concentrated in vacuum. The crude material was loaded onto a silica gel columnand purified by flash chromatography.General procedure: A solution of nano CuO (0.010 mmol) and substituted phenylboronic acid (1 mmol) in H2O (2 mL) was stirred at 25 °C for 2 h under aerobic condition. After the reaction was over, the reaction mixture was extracted with ethyl acetate and washed with doubledistilled water in a separating funnel. The organic layer was separated and collected in a conical flask. After evaporation of the solvent in a rotary evaporator, reaction mixture was subjected to column chromatography on silica gel column (ethyl acetate/hexane, 1:10) to afford the respective product.General procedure: 4.3. Catalytic tests: general procedure I for the Cu2(ophen)2catalyzed homocoupling for Table 2 A solution of the corresponding arylboronic acids (1.0 mmol), Cu2(ophen)2 (1.3 mg, 0.5 mol percent), DMF (1.0 mL) in 5 mL round-bottomed ask was stirred under air and the reaction was moni-tored by TLC. After the substrate was consumed, the reaction con-versions were determined bygas chromatography (GC) analysis (FIDfrom AGILENT 7820) using a cross-linked (95percent)-dimethyl-(5percent)-diphenylpolysil-oxane column (HP-5, 30 m0.32 mm0.25 mm), helium, injector temperature 250 C, detector temperature 300 C, and oven temperature program 45 C (3 min)e20C/mine280 C(2 min). The resulting mixture was poured into brine (10 mL), andextracted with diethyl ether (310 mL). The organic layer waswashed with brine, dried over Mg2SO4, the residue was chromato-graphed via a short column of silica gel (petroleum ether: diethylether15:1) and evaporated under reduced pressure. The productswas determined by 1H NMR spectroscopy. All 1H NMR spectra weremeasured in CDCl3 with TMS as the internal standard.General procedure: In a 25-mL round-bottomed flask, a solution of copper(II)complex (2 mol percent) and substituted phenylboronic acid (1.5 mmol)in methanol (5 mL) was stirred at room temperature for 3e4 h. Theprogress of the reaction was monitored by TLC. After completion ofthe reaction, the solvent was removed and the product was washedwith water and extracted with ethyl acetate (3 10 mL). Thecombined organic layers were dried over Na2SO4 and the solventremoved under reduced pressure to give crude product which waspurified by column chromatography by using petroleum ether/ethyl acetate (4:1) as an eluent.Representative experimental procedure: A mixture of AuCl (11.6 mg, 0.050 mmol), phenylboronic acid (1a, 121.9 mg, 1.00 mmol), K2CO3 (152.0 mg, 1.10 mmol) in EtOH (8.0 mL) was heated at 50 °C under open air for 24 h. The reaction mixture was filtered through a plug of Florisil.(R). washing with hexane-AcOEt (3:1). The filtrate was concentrated under reduced pressure, and the resulting residue was subjected to preparative thin-layer chromatography (hexane:AcOEt = 20:1) to afford biphenyl (2a, 58.6 mg, 76percent).In a 25 mL beaker1 g of 4-tert-butylbenzeneboronic acid, 0.2 g of Cs2C03, 3 mL of DMF and (hi g catalyst (complex 1)The reaction was complete, 10 mL of CH2CI2 was extracted and washed with 20 mL of distilled water. The organic phase was dried with sewage MgS04, filtered and the solution was removed and the crude product was obtained. The reaction mixture was stirred at room temperature for 1 hour. The petroleum ether eluted the column to give 4, 4-di-tert-butylbiphenyl.At 25 mL Weigh 1 g in the beaker 4-tert-butylbenzeneboronic acid, 0.2 g Cs2C03, 3 mL DMF and 0.1 g catalyst (Complex 1), The mixture was stirred at room temperature for 1 hour, TLC monitoring (RhoEpsilon: EpsilonAlpha = 1: 1) The reaction was complete, 10 mL of CH2CI2 after extraction of the product And then washed with 20 mL of distilled water, Organic phase with sewage MgS04 dry, Filtration, desolvation, The resulting crude product was eluted with petroleum ether Column, get 4, 4-di-tert-butylbiphenylWeigh 1 g of 4-tert-butylphenylboronic acid in a 25 mL beaker, 0.2 g Cs2CO3, 3 mL DMF and 0.1 g catalyst (complex1), Stir at room temperature for 1 hour, TLC monitoring (PE:EA = 1:1) Complete reaction, 10 mL CH2Cl2The product is extracted and washed with 20 mL of distilled water. The organic phase is treated with effluent MgSO'4Drying, filtration, desolvation, and the resulting crude product was eluted through a column with petroleum ether to give 4, 4'-di-tert-butylbiphenyl.Example 4 - Preparation of 4, 4'-Di-t-butylbiphenyl. Into a 250 ml 3-neck round bottom flask equipped with a mechanical stirrer, thermometer, and inlet was charged, with agitation, 40 mL of nitromethane to which was added portionwise 20.7 grams (156 mmol, 1.69 eq) of aluminum chloride with agitation and cooling so as not to exceed 40° C. This solution was added to a mixture of 14.2 grams (92.1 mmol, 1.0 eq) of biphenyl and 26.5 grams (120 mmol, 1.3 eq) of 2, 6-di-t-butyl-4-methylphenol in 40 mL of nitromethane at 15° C. over a period of 5 to 10 minutes. The mixture turned a dark opaque color and near the end of the addition, the mixture became very thick. The reaction mixture was allowed to stir for 30 minutes and then poured into ice-water. The mixture was extracted with ether twice and the ether layer was concentrated in vacuo. Additional ether was added to the solid and the mixture was concentrated in vacuo. Toluene was added to the solid and the mixture was concentrated in vacuo. This treatment was to insure removal of nitromethane before washing with base. The brown solid residue was dissolved in ether and washed with approximately 300 mL of 1M sodium hydroxide until the aqueous layer was no longer deeply colored. The organic layer was washed with water and concentrated in vacuo. The brown residue was recrystallized from approximately 150 mL of ethanol to give 10 grams (41percent yield). Melting point=129°-130° C.

Molecular Weight:266.4
XLogP3:7.7
Rotatable Bond Count:3
Exact Mass:266.203450829
Monoisotopic Mass:266.203450829
Heavy Atom Count:20
Complexity:253
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes