Of triphenylbismuth

Biphenyl formation by the ligand coupling of triphenylbismuth is promoted by Pd(OAc) [418],... 

Although it was first prepared by Verma et al. in 1983 starting from Bi(III) trifluoroacetate [58], our group developed another strategy for the preparation of Bi(OTf)3 [32]. The key point of our synthetic strategy is based on the acidic cleavage of the three carbon-bismuth bonds of triphenylbismuth by triflic acid in dichloromethane (Scheme 1). A study of the hydration of Bi(0Tf)3xH20 revealed that this compound can exist as three different hydrates, the nonahydrate, the tetrahydrate, and the dehydrate [35], The structures of the nona- and tetrahydrate forms have been determined by ab-initio calculations [35] and XRD [36]. 

When treated with a mixture of triphenylbismuth dibromide (Ph3BiBr2) and iodine, tertiary and secondary alcohols are converted to the corresponding most stable alkenes under mild conditions. Sesquiterpinic alcohol is dehydrated to cedrene by this binary system (Equation (143)).236 Irradiation of tri(/>-tolyl)bismuth diazide in benzene in the presence of acetylenes results in the transfer of one of the azido ligands to the triple bond, affording 1,2,3-triazoles in moderate yields (Equation (144)).237... 

Malysheva YB, Gushchin AV, Mei Y, Lu Y, Ballauff M, Proch S, Kempe R (2008) C-C coupling reaction of triphenylbismuth(V) derivatives and olefins in the presence of palladium nanoparticles immobilized in spherical polyelectrolyte brushes. Eur J Inorg Chem 3 379-383... 

Triphenylbismuth diacetate, (CsHOjBiiOCOCH,), (1). Mol. wt. 558.37, m.p. 162°. The reagent is prepared by reaction of triphenylbismuth carbonate with acetic acid. 

Pentavalent derivatives of triphenylbismuth such as p,-oxobis(chlorotriplienylbismudi) (1) and triphe-nylbismuth carbonate (2) have been developed recently as oxidizing agents which cleave a-glycols into the corresponding carbonyl derivatives (equation 1). Aldehydic products do not undergo further oxidation. Reagent (1) also oxidizes saturated ilcohols as well as allylic and benzylic alcohols, whereas (2) selectively oxidizes allylic alcohols in the presence of saturated alcohols. ... 

Low toxicity of triphenylbismuth was also shown by Schafer and Bowles . 

The first bismuthonium ylide to be prepared and isolated was triphenylbismuthonium tetraphenylcyclopentadienylide, made by thermal decomposition of diazotetraphenylcyc-lopentadiene in the presence of triphenylbismuth . More recently some other bismuthonium ylides (Pli3Bi=CX2, X = RCO or RSO2) have been prepared and isolated by the diazo method, using copper hexafluoroacetylacetonate as catalyst... 

In the case of polyhydroxylic phenols, perphenylation occurred. Thus, phloroglucinol (28) reacted with triphenylbismuth carbonate to give a mixture of 2,4,6-triphenylphloroglucinol (29) and 2,2,4,5-tetraphenylcyclopent-4-en-l,3-dione (30).24 The dione (30) is formed from (29) by phenylation, decarboxylation and oxidation. When a large excess of triphenylbismuth carbonate (5 mol equiv.) was used, the dione (30) was the only isolated product in 60% yield. In contrast, the reaction of phloroglucinol with pentaphenylbismuth led to a complex mixture.25... 

O-Phenylation of tertiary alcohols can be realized through reaction with pentaphenylbismuth (4), a benzyne intermediate being involved. r rf-Butyl phenyl ether (80) was also obtained in rather low yields in the reaction of triphenylbismuth diacetate with rerr-butyl alcohol used as solvent in the presence of potassium carbonate or by reaction of triphenylbismuth dichloride with lithium ten-... 

The reaction of triphenylbismuth diacetate (47) with secondary alcohols under neutral conditions resulted in poor to moderate yields of the corresponding 0-phenyl ethers 2-propanol gave about 20% of the 0-phenyl ether with a large excess of the dcohol, cyclohexanol less than 3% and 3p-cholestanol gave 36% of the 0-phenyl ether. Moreover, no reaction was observed between triphenylbismuth diacetate and primary alcohols.53-55... 

The observation of a catalytic effect of copper salts on the decomposition of triphenylbismuth diacylates led to the development of a copper-catalysed arylation reaction by triarylbismuth derivatives in the presence of copper or its metallic salts. 

Optically active (S)-6,6 -diphenoxy-2,2-biphenyldiols (107) were obtained by diphenylation of a menthyl-protected 2,2, 6,6-biphenyltetrol (106) by treatment with an excess of triphenylbismuth diacetate (4 molar equiv.) in benzene in the presence of metallic copper. The 2,2 -diphenoxy derivative was obtained in 48% yield and quantitatively deprotected to give (107). ... 

In the phenylation reaction of substituted anilines, the electronic nature of the substituents plays a role only on the reaction rate, not on the overall yield (4-methoxyphenyl 91% after 15 minutes and 4-nitrophenyl 90% after 16 hours). The steric hindrance is also a factor which influences the reaction in slowing down the reaction rate. To obtain good to excellent yields, an excess of bismuth reagent is then required with hindered substrates. For example, mesitylamine required 2.2 equivalents of triphenylbismuth diacetate to afford the AT-phenyl derivative in 92% after 24 hours. Moreover, triphenylamine was obtained in 23% yield after 48 hours by arylation of, iV-diphenylamine. A variety of aliphatic, alicyclic, heterocyclic and aromatic amines as well as hydrazines were N-arylated by this system. No reaction took place with a-amino acids but their esters were mono-iV-phenylated under... 

To a stirred suspension of triphenylbismuth dichloride (2.56 g, 5 mmol) in 95% ethanol (60 ml) was added hydrazine hydrate (2.0 g). Reduction occurred immediately. The solution was decolorized and triphenylbismuthine precipitated out of solution. Stirring was continued for 1 h and then the mixture was poured into water (300 ml). The aqueous suspension was extracted with ether, the organic layer was separated and dried, and the solvent was removed to give the product (2.1 g, 95.4%), m.p. 75-76°C [40JA665]. 

A benzene solution of triphenylbismuth dichloride and an aqueous solution of silver acetate were mixed with vigorous stirring. The benzene layer was then separated and concentrated under reduced pressure. Dilution with light petroleum caused triphenylbismuth diacetate to precipitate. This was recrystallized from a mixture of benzene and light petroleum, m.p. 173°C [70CJC2488]. 

Treatment of triphenylbismuth carbonate with sulfonic acids aifords triphenylbismuth disulfonates, which are converted to triphenylbismuth dichloride by metathesis [86ZAAC(539)110]. 

Triethylamine (1 g, 9.9 mmol) was added to a benzene solution of triphenylbismuth dibromide (1.2 g, 2 mmol) and ethylthioacetic acid (1.2 g, 5 mmol). After stirring for 1 h, the precipitated triethylamine hydrobromide was filtered off, and the filtrate was evaporated. The residue was recrystallized from acetonitrile to obtain the corresponding dicarboxylate (m.p. 119°C) [75JINC(37)2559]. 

Metathesis of triarylbismuth dichloride with a variety of metal salts such as fluoride, azide, cyanide, carboxylates and sulfonates has been used frequently for the synthesis of triarylbismuth(V) compounds of the type Ar Bi Y 2, where Y is the corresponding anionic group (Section 3.1.1). The reaction of triphenyl-bismuth dichloride with mercuric chloride in an alkaline medium leads to triphenylbismuthine, while treatment of triphenylbismuth dicyanide with mercuric oxide results in the formation of triphenylbismuthine oxide (Section... 

Pentacoordinate cationic complexes of the type (Ph3BiL2)Y2 can be prepared by the reaction of triphenylbismuth dichloride with a silver salt AgY in the presence of a ligand molecule L [73IC944]. These complexes are stable in the solid state, but decompose in solution. Triphenylbismuth difluoride is formed from the thermal decomposition of [Ph3Bi(OAsPh3)2][BF4]2. 

The reaction of triphenylbismuth carbonate with cyclic 1,3-dicarbonyl compounds, such as dimedone and Meldrum s acid, gives highly stabilized triphenylbismuthonium ylides (Section 3.5.1). Moderately stabilized acyclic bismuthonium ylides can be prepared from triphenylbismuth dichloride and a 1,3-diketone or a 1,3-disulfone in the presence of a suitable base. A similar base-promoted reaction of triphenylbismuth dihalides with Al-sulfonylamines or amides has been used for the preparation of stabilized bismuthine imides bearing the Af-sulfonyl or Af-acyl moiety (Section 3.6.1). 

Typical reaction modes of triarylbismuth dihalides and derivatives are shown in Scheme 3.4. Representative reactions of triphenylbismuth dichloride are listed in Table 3.5. 

---