6-Phenyl-2,2 -bipyridine, reaction with

Bipyridine-derived cycloaurated complexes have also been synthesised through the transmetallation route. Conversion of 6-phenyl-2,2 -bipyridine to its organomercury derivative 58, followed by reaction with Na[AuCl4] gave the cycloaurated complex 59 in 38% yield as its [AuC14] salt.39... 

The treatment of 2,2 -bipyridine with diiodomethane yields a dipyridoimidazolium salt (98), and a similar reaction with benzylidene chloride gives a 6-phenyl derivative of (98) <63TL95,65AJC1819>. Alkyl substituted 2,2 -bipyridines react in a similar way with these two reagents but other alkylidene halides are inert. 

Reaction with bipyridine 8,4.8.2.3.2 Reaction with l- -butyl-3,4-dimethylphosphole 8,4.8.3.7.1 Reaction with 1-phenyl-3,4-dimethylphosphole 8,4.8.3.7.1 Reaction with l-propyl-3,4-dimethylphosphole 8,4.8.3.7.1 Reaction with 1,3,4-trimethylphos-phole 8, 4.8.3.7.1 CljHgISl CljSiHgl... 

In a similar way, nucleophilic substitution of hydrogen in 1,2,4-triazine 31 with lithium derivatives of polynuclear arenes (pyrene, phenanthrene, triphenylene), followed by an aza-DA reaction with 2,5-norbornadiene or morphohnocyclopentene gave the novel polyarenes, modified photolumi-nescent 5-phenyl-2,2 -bipyridines 32 (14MC117). 

To complete the section on the synthesis of 4,4 -bipyridines, we summarize the methods reported for the preparation of some substituted 4,4 -bi-pyridines and 4,4 -bipyridinones. These methods are closely analogous to syntheses already discussed for some of the isomeric bipyridines. Thus the Hantzsch reaction using pyridine-4-aldehyde, ethyl acetoacetate, and ammonia gives 3,5-di(ethoxycarbonyl)-1,4-dihydro-2,6-dimethyl-4,4 -bipyridine, which after oxidation, followed by hydrolysis and decarboxylation, afforded 2,6-dimethyl-4,4 -bipyridine. Several related condensations have been reported. Similarly, pyridine-4-aldehyde and excess acetophenone gave l,5-diphenyl-3-(4-pyridyl)pentane-l,5-dione, which with ammonium acetate afforded 2,6-diphenyl-4,4 -bipyridine. Alternatively, 1-phenyl-3-(4-pyridyl)prop-2-enone, A-phenacylpyridinium bromide, and ammonium acetate gave the same diphenyl-4,4 -bipyridine, and extensions of this synthesis have been discribed. Condensation of pyridine-4-aldehyde with malononitrile in the presence of an alcohol and alkaline catalyst produced compounds such as whereas condensations of... 

Electrophilic substitution reactions primarily occur meta to the nitrogen atoms, while more common nucleophilic substitutions typically take place at positions ortho and para to nitrogen. For example, methyl lithium and phenyl lithium were reacted with 4,4 -diBu bipyridine to generate 6,6 -dimethyl-4,4 -diBu bipyridine and 6,6 -diphenyl-4,4 -diBut bipyridine, respectively, in high yield.62... 

The composition and formation constants of silver complexes with 6-phenyl-2,2 -bipyridine (bpp, 197), in propylene carbonate solution (198), were determined poten-tiometrically. Cyclic voltametry and galvanostatic coulometry were used to determine the normal potential of the reduction processes of Ag(II) to Ag(I), as depicted in reactions 28 and 29265. 

Under a nitrogen atmosphere, 2-(2 -octynyloxy)-l-phenylethanone (1) (136 mg, 0.5 mmol) was added to a mixture of Pd(OAc)2 (5.6 mg, 0.025 mmol), 2,2 -bipyridine (4.5 mg, 0.030 mmol), HO Ac (1 mL), and 1,4-dioxane (4 mL). The solution was stirred at 80 °C for 14 hours until the reaction was complete as monitored by TLC. On cooling, the reaction mixture was neutralised with saturated sodium hydrogencarbonate, and then extracted with diethyl ether (3 x 20 mL). The combined ether solution was washed with saturated sodium chloride, dried with sodium sulfate and concentrated. The residue was purified by flash chromatography on silica gel (EtOAc/petroleum ether 1/4) to give the product 3-phenyl-3-hydroxy-4-(l -acetoxyhexylidene)tetrahydrofuran (2) in 80% yield as a white solid m.p. 79.5-80.5 °C. 

For example, the acyl-aryloxo bond cleavage (type b) is shown by the reaction of Ni(cod)2 with phenyl propionate in the presence of PPhs (Scheme 3.34) or 2,2 -bipyridine [65]. The reaction products are ethylene, phenol, and (car-bonyl)nickel complex. Formation of these products is conveniently understood by initial oxidative addition of EtC(0)-0Ph followed by decarbonylation, )S-hydrogen elimination and reductive elimination, though (acyl)(aryloxo)nickel(II) intermediate is not isolated. However, such an intermediate is isolated by the selective insertion of CO into the (alkyl)(aryloxo)nickel (or palladium) complexes, which smoothly affords esters by reductive elimination promoted by electron deficient olehns. The results suggest that the oxidative addition involving C-0 bond cleavage is essentially reversible. 

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