Bismuth compounds reactions with

The redistribution reaction in lead compounds is straightforward and there are no appreciable side reactions. It is normally carried out commercially in the liquid phase at substantially room temperature. However, a catalyst is required to effect the reaction with lead compounds. A number of catalysts have been patented, but the exact procedure as practiced commercially has never been revealed. Among the effective catalysts are activated alumina and other activated metal oxides, triethyllead chloride, triethyllead iodide, phosphorus trichloride, arsenic trichloride, bismuth trichloride, iron(III)chloride, zirconium(IV)-chloride, tin(IV)chloride, zinc chloride, zinc fluoride, mercury(II)chloride, boron trifluoride, aluminum chloride, aluminum bromide, dimethyl-aluminum chloride, and platinum(IV)chloride 43,70-72,79,80,97,117, 131,31s) A separate catalyst compound is not required for the exchange between R.jPb and R3PbX compounds however, this type of uncatalyzed exchange is rather slow. Again, the products are practically a random mixture. 

Reactions of bismuth compounds with hydrides to form Bi—M-containing compounds are not known . ... 

The chemistry of carbanions stabilized by the heavy main group elements has been extensively investigated by Kauffmann, and a thorough description of his work can be found in a recent review. There are many similarities between the elements. The anions stabilized by the heavy main group elements listed above can generally be alkylated, and in some cases their reaction with carbonyl compounds is a useful alternative to the Wittig reaction. All the stabilized metallomethyl lithium anions (except bismuth) exhibit marked thermal stability. 

Aldoses and ketoses, similar to aldehydes, reduce heated Tollens reagent (see p. 210), Nessler s reagent (p. 211), Fehling s reagent [p. 210 see also (55)], and also Nylander s reagent (an alkaline solution of a bismuth salt) and a solution of ammonium molybdate. The reaction with nitro compounds should also be mentioned here. 

The pyrometaHurgical processes, ie, furnace-kettle refining, are based on (/) the higher oxidation potentials of the impurities such as antimony, arsenic, and tin, ia comparison to that of lead and (2) the formation of iasoluble iatermetaUic compounds by reaction of metallic reagents such as 2iac with the impurities, gold, silver and copper, and calcium and magnesium with bismuth (Fig. 12). 

One-part urethane sealants (Table 3) are more compHcated to formulate on account of an undesirable side reaction between the prepolymer s isocyanate end and water vapor which generates carbon dioxide. If this occurs, the sealant may develop voids or bubbles. One way to avoid this reaction is to block the isocyanate end with phenol and use a diketamine to initiate cure. Once exposed to moisture, the diketamine forms a diamine and a ketone. The diamine reacts with the isocyanate end on the prepolymer, creating a cross-link (10). Other blocking agents, such as ethyl malonate, are also used (11). Catalysts commonly used in urethane formulations are tin carboxylates and bismuth salts. Mercury salt catalysts were popular in early formulations, but have been replaced by tin and bismuth compounds. 

Bismuth trichloride shows considerable tendency to form addition compounds. Reaction with ammonia yields the colodess, easily volatili2ed bismuth trichloride triammine [66172-89-2] BiCl ANH, as well as the red, thermally unstable bismuth trichloride hemiammine [66172-90-5] 2BiCl2 NH. Compounds of formula BiCl NO, BiCl 2N02, and BiCl NOCl may be isolated these are stable in dry air but are decomposed by moisture. Bismuth... 

Bi2(SC6F5)6((i-X)] or [Bi3(SC6 F f/ii- Br)2]2 have been obtained by reaction of [Bi(SCf,F5L3] with halide anions.192 The reaction of BiBr3 with PhSeSiMe3 gives clusters, such as [Bi4(p-SePh)5(SePh)g] (20) or [Bi6(p-SePh)6 (SePh)10Br2].193 The use in medicine of bismuth compounds has lead to the... 

To elucidate the reaction pathway, deuterium-labeled allenyl pinacol boronate 10 was prepared, and the addition reaction with hydrazonoester 6 was conducted in the presence of Bi(OH)3 and Cu(OH)2 (Scheme 4). In both Bi- and Cu-catalyzed cases, the reactions proceeded smoothly (in quantitative yields in both cases). In the Bi(OH)3-catalyzed reaction, a major product was allenyl compound 11, in which the internal position was deuterized. It was assumed that a propargyl bismuth was formed via transmetalation from boron to bismuth, followed by addition to hydrazonoester via y-addition to afford allenyl compound 11. Thus, two y-additions could selectively provide a-addition products [75, 76, 105, 106]. It was confirmed that isomerization of 10 did not occur. Recently, we reported Ag20-catalyzed anti-selective a-addition of a-substituted allyltributyltin with aldehydes in aqueous media [107], On the other hand, in the Cu(OH)2-catalyzed reaction, a major product was propargyl compound 12, in which the terminal position was deuterized. A possible mechanism is that Cu(OH)2 worked as a Lewis acid catalyst to activate hydrazonoester 6 and that allenyl boronate 10 [83-85] reacted with activated 6 via y-addition to afford 12. 

Scheme 11 Reactions of bismuth ylides with a-dicarbonyl compounds [46, 67-70]...

Cyclic triarylbismuth(III) compounds also undergo the Pd-catalyzed cross-coupling reaction with benzoyl chloride (Scheme 27) [42]. The exocyclic aryl group was selectively transferred to form 4-methylbenzophenone in good yield. Bismuth-containing products could not be isolated except for the cyclic bismuth compound possessing a SO2 moiety, for which cyclic bismuth chloride was isolated in 86% yield. 

Aryl chlorides can also be used as coupling partners for azabismocine reagents 2. In the coupling reaction with aryl chlorides, Pd(PPh3)4 was not an efficient catalyst, and Pd(OAc)2/l,l,-bis(diphenylphosphino)ferrocene (dppf) combination was found to be effective [54]. Not only the arylation, but also methylation, alkenylation and alkynylation reactions can be accomplished by using the corresponding bismuth compounds (Scheme 35). The addition of CsF improved the product yields. However, electron-rich aryl chlorides were unable to be coupled efficiently under these reaction conditions. 

Condensation of A -acylglycines with carbonyl compounds, the Erlenmeyer synthesis, continues to be exploited to prepare of a wide variety of unsaturated-5(47/)-oxazolones. The reaction is performed in the presence of a cyclodehydrating agent and recently bismuth(lll) acetate has been evaluated in this capacity. Alternatively, unsaturated 5(47/)-oxazolones can be obtained from hippuric acid and a carbonyl compound or from the appropriate dehydroamino acid derivative using 3-(aIkoxycarbonyl)benzotriazole-l-oxides as the cyclodehydrating agent. 

Among the group 16 elements, mostly non-metallic ones like TeCl were examined [11]. The reaction with TeCU proceeds in a stepwise manner giving the mono-alkyltellurium and the dialkyl compound in accordance with the stoichiometry of the reagents Eq. (21). As in the case of tin and bismuth, the second alkylation is much slower than the first and the dialkyl species could not be alkylated any further. 

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