P-Tolyl cyanide

Experiment 6.76 p-TOLUNITRILE (p-Tolyl Cyanide) p-Me-C6H4-NH2 p-Me-C6H4-N=N Cl p-Me-C6H4-CN... 

Preparation of 2-bromo-3-(p-tolyl)propene (typical procedure) A three-necked, 50 mL flask equipped with an argon inleL a rubber septum and an internal thermometer was charged with bis(p-bromophenyl)ditelluride (1.7 g, 3.0 mmol, 1 equiv) and Ni(acac)2 (77 mg, 0.3 mmol, 10 mol%). The reaction mixture was cooled to -40°C and THF (6 mL) was added. It was further cooled to -78°C and Et2Zn (1.5 mL, 15 mmol, 5 equiv) was slowly added via syringe. The reaction was allowed to warm to room temperature and was stirred for 6 h. Meanwhile, a mixture of copper cyanide (2.68 g, 23 mmol) and lithium chloride (2.54 g, 60 mmol) was dried under vacuum (130°C, 2 h) and dissolved in THF (10 mL). This solution was added to the reaction mixture at -60°C, followed by 2,3-dibro-mopropene (6.0 g, 30 mmol, 10 equiv). The reaction mixture was warmed up to room temperature and worked up as usual. The crude oil obtained after evaporation of the solvents was purified by flash chromatography (hexanes), affording the product (1.45 g, 5.2 mmol, 88% yield) as a colourless oil. 

Druliner et al. (46) studied the addition of hydrogen cyanide to a variety of NiL4 complexes and found that both electronic and steric factors are important in the stability of the HNiL3CN complexes (Table III). For example, Ni[P(0-o-tolyl)3]4 and Ni[PEt3]4 react immediately and quantitatively with HCN to give HNiL3CN, whereas the equilibrium position of Eq. (17) remains far to the left with Ni[P(0-p-tolyl)3]4 the equilibrium constant in the latter case has been estimated to be 4 x 10-4 from visible/UV spectra in benzene at 25°C (47). The corresponding K for L = P(0-o-tolyl)3,... 

ASYMMETRIC SYNTHESIS Diboiane. Diisopinocamphenylborane. Hydrogen cyanide. (-) and (+)-2,3-0-Isopropylidene-2,3-dihydroxy-l,4-bis(diphenylphosphino)-bntane. (+)- R)-/r ns- 3-Styryl-p-tolyl sulfoxide. p-Tolylsulfinylcaibonion lithium salt. 

However, the ethoxy group of l-ethoxy-2-propylbuta-l,3-diene is no longer present. Evidently the p-toluensulphonyl cyanide (2) undergoes [4+2] cycloaddition to l-ethoxy-2-propylbuta-l,3-diene (i). The resulting dihydropyridine 3 aromatises with 1,4-elimination of ethanol to form 2-p-tolyl-sulphonyl-5-propylpyridine (4). 

The following examples illustrate different aspects of Scheme 1 in operation. p-Chlorophenyl azide, malononitrile, and methanolic sodium methoxide, set aside, gave 4-amino-5-cyano-3-p-chlorophenyltriazole (rC, 1 hr, 98%) (60CB2001). Methanolic sodium methoxide was added dropwise to a mixture of p-tolyl azide and phenylacetonitrile (benzyl cyanide) next day, the temperature was raised to 25°C, and the preparation set aside for 10 hr, giving 4-amino-5-phenyl-3-p-tolyltriazole (92%) (57JOC654). 

The entrance into the catalytic cycle from complex 5 may occur via a small equilibrium concentration of Ni-(la)-(MVN) complex6 (pathA, Schemes) and/or via oxidative addition of HCN to generate the species Ni-[la]-HCN, 7 (pathB). In either event, formation of the hydridoalkene complex Ni-[1]-(MVN)(H)(CN), 8, occurs and is followed by an insertion reaction to produce the (ri -benzyl)nickel cyanide intermediate 9. Although this allyl-type species has not been directly detected, the exclusive formation of the branched nitrile supports its intermediacy. Analogous intermediates have been postulated in the hydrocyanation of 1,3-butadiene with NilPlO-o-tolylljjj or Ni[P(OEt)3]4 and in the hydrocyanation of styrene with Ni[P(0-p-tolyl)3]4. Examples of other nick-el-benzyl complexes exhibiting similar allylic interactions in the solution and solid state are also known. 

The required ketosulfoxide 69 (Scheme 15) was obtained in two steps in a one-pot procedure from 1,4-dimethoxybenzene (66). Ortho Hthiation of 66, lithium-copper exchange, and addition to methyl acrylate gave ester 67. Reaction of the anion obtained from (R)-methyl(p-tolyl)sulfoxide (68) [89] by treatment with LDA, with ester 67 afforded ketone 69. Diastereoselective addition of diethylaluminum cyanide to the carbonyl group of 69 [90] furnished sulfinylcyanohydrin 70 as the sole product. The (S) configuration of the new stereogenic center was inferred from the previous studies of acycUc P-ketosulfoxides [91,92]. 

Organogold carbene compounds [Au(carbene)(CN) j iR ] can be obtained from com-plexed cyanides [Au(CN)m(C6F5) ] (n = 1 or 3, m = 1 and n = m = 2) by sequential alkylation (to form isocyanide complexes) and nucleophilic attack of amine" . Gold(III) diisocyanides [Au(CNR)2(CgF5)2]+ (R = Ph or p-tolyl), which can also be obtained by isocyanide substitution of ether in [Au(C6F5)2(OEt2)2] > react with hydrazobenzene NH(Ph)NHPh and hydrazine or phenyUiydrazine according to the reactions in Scheme 32 to furnish cyclic bis(carbene) and cyclic carbene-imidoyl compounds . ... 

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