Allyl chloride, carbonylation

Benzoic acid and naphthoic acid are formed by the oxidative carbonylation by use of Pd(OAc)2 in AcOH. t-Bu02H and allyl chloride are used as reoxidants. Addition of phenanthroline gives a favorable effect[360], Furan and thiophene are also carbonylated selectively at the 2-position[361,362]. fndole-3-carboxylic acid is prepared by the carboxylation of 1-acetylindole using Pd(OAc)2 and peroxodisulfate (Na2S208)[362aj. Benzoic acid derivatives are obtained by the reaction of benzene derivatives with sodium palladium mal-onate in refluxing AcOH[363]. 

Aldehydes can also be prepared by the carbonylation of aryl and alkenyl halides and triflate, and benzyl and allyl chlorides using tin hydride as a hydride source and Pd(PhjP)4 as a catalyst[377]. Hydrosilancs arc used as another hydride source[378]. The arenediazonium tetralluoroborate 515 is converted into a benzaldehyde derivative rapidly in a good yield by using Et ,SiH or PH MS as the hydride source[379]. 

The reaction of allyl halides with terminal alkynes by use of PdClifFhCNji as a catalyst affords the l-halo-l,4-pentadienes 297. 7r-AlIylpalladium is not an intermediate in this reaction. The reaction proceeds by chloropalladation of the triple bond by PdCh, followed by the insertion of the double bond of the allyl halide to generate 296. The last step is the regeneration by elimination of PdCh, which recycles[148]. The cis addition of allyl chloride to alkynes is supported by formation of the cyclopentenone 299 from the addition product 298 by Ni(CO)4-catalyzed carbonylation[149]. 

The majority of catalytic enantioselective allylation reactions involve the chiral Lewis-acid-catalysed additions of allylsilanes or allylstannanes to carbonyl compounds. Monothiobinaphthol has been used by Woodward et al. as a chiral promoter in the enantioselective catalytic allylation of aryl ketones with impure Sn(allyl)4, prepared from allyl chloride, air-oxidised magnesium and SnCl4. Therefore, the allylation of arylketones in these conditions was achieved very efficiently, since the corresponding allylic alcohols were formed in... 

Mediated by Tin. In 1983, Nokami et al. observed an acceleration of the reaction rate during the allylation of carbonyl compounds with diallyltin dibromide in ether through the addition of water to the reaction mixture.74 In one case, by the use of a 1 1 mixture of ether/water as solvent, benzaldehyde was allylated in 75% yield in 1.5 h, while the same reaction gave only less than 50% yield in a variety of other organic solvents such as ether, benzene, or ethyl acetate, even after a reaction time of 10 h. The reaction was equally successful with a combination of allyl bromide, tin metal, and a catalytic amount of hydrobromic acid. In the latter case, the addition of metallic aluminum powder or foil to the reaction mixture dramatically improved the yield of the product. The use of allyl chloride for such a reaction,... 

The allylation of aldehydes can be carried out using stannous chloride and catalytic cupric chloride or copper in aqueous media." In-situ probing provides indirect (NMR, CV) and direct (MS) evidence for the copper(I)-catalyzed formation of an allyltrihalostannane intermediate in very high concentration in water (Scheme 8.6). Hydrophilic palladium complex also efficiently catalyzes the allylation of carbonyl compounds with allyl chlorides or allyl alcohols with SnCl2 under aqueous-organic... 

Carbonylation of a mixture of allyl chloride and butadiene with PdCl2 was carried out, and 3,7-octadienoate (76) was obtained as one product (79, 80) ... 

Allyl chlorides are readily deprotonated a to the halide by strong bases to give allyl carbenoids, which insert into organozirconocene chlorides to afford allyl- or pentadienyl-zirco-nocene chlorides (Scheme 3.23). These allylmetallic species are reactive towards carbonyl compounds, and so an efficient three-component coupling results [50]. 

The phase-transfer catalysed reaction of nickel tetracarbonyl with sodium hydroxide under carbon monoxide produces the nickel carbonyl dianions, Ni,(CO) 2- and Ni6(CO)162, which convert allyl chloride into a mixture of but-3-enoic and but-2-enoic acids [18]. However, in view of the high toxicity of the volatile nickel tetracarbonyl, the use of the nickel cyanide as a precursor for the carbonyl complexes is preferred. Pretreatment of the cyanide with carbon monoxide under basic conditions is thought to produce the tricarbonylnickel cyanide anion [19], as the active metal catalyst. Reaction with allyl halides, in a manner analogous to that outlined for the preparation of the arylacetic acids, produces the butenoic acids (Table 8.7). 

Allyl chlorides and bromides are readily carbonylated to unsaturated acids using nickel cyanide and phase transfer catalysis conditions. Mechanistic studies revealed that the key catalytic species in this reaction is the cyanotricarbonylnickelate ion(20). 

Photolytic. Anticipated products from the reaction of allyl chloride with ozone or OH radicals in the atmosphere are formaldehyde, formic acid, chloroacetaldehyde, chloroacetic acid, and chlorinated hydroxy carbonyls (Cupitt, 1980). 

Allyl chlorides and bromides can be carbonylated to afford the respective unsaturated acids and esters with a variety of catalysts under relatively mild conditions such as 30-50 °C and 1 bar CO (Scheme 5.2). Most prominent are the palladium-containing catalysts and both [PdCl2(TPPMS)2] or [PdCl2(TPPTS)2] and [PdCl2(PPh3)2] were used, dissolved in the aqueous and in the organic phases, respectively [14-16]. 

In the carbonylation of allyl halides the highly toxic [Ni(CO)4] catalyst could be replaced by [Ni(CN)2], which yielded [Ni(CN)(CO)jr under the reaction conditions [17]. The cyanotricarbonylnickel(0) anion is a versatile catalyst of carbonylations under phase transfer conditions [18], however, hydroxycarbonylation of allyl chloride proceeds effectively without PT catalysts in a genuine biphasic system, as well. 

Reformatsky reactions between allyl chloride and carbonyl cortqiounds are also effected in protic solvents using aluminium and a catalytic amount of tin chloride. Finely divided tin is formed and organotin reagents are involved as intermediates. These react with the carbonyl compound releasing tin ions, which are recycled by the dissolving aluminium [189],... 

Alkyl halides possessing / -hydrogens are usually poor substrates for carbonylative cross-coupling due to competitive / -hydride elimination/ Allyl chlorides can be used in carbonylative cross-coupling with allylstannanes/ phenyl-, 3-furyl, or vinylstannanes " to afford allylketones in modest to good yields. Divinylketones can be accessed through the reaction of vinylstannanes with vinyl iodides or vinyl triflates, with the latter requiring the addition of LiCl. Synthetic potential of this method has been proved in the formation of macrocyclic ketone jatrophone. In the reaction of vinyl triflates with tetramethyltin or aryltrimethylstannanes the additional activation by ZnCle is required. 

The 3.7-octadienoate 399 is obtained by the carbonylation of allyl chloride and butadiene[255]. 

PdCl2(tppts)2 exhibited high catalytic activity (TOF=1860 h-1) for the carbonylation of allyl chloride to the desired product p,y-butenoic acid [Equation (8)] at 40°C and atmospheric CO pressure in an aqueous(NaOH)/toluene two phase system471 By-products were a,P-butenoic acid and allyl alcohol. The yield of butenoic acids was 94% with a 3,y/a, 3 ratio of 21 471... 

The concept of CPTC has been applied in a large number of catalytic reactions such as reduction of allyl chlorides with HCOONa, carbonylation of aryl and allyl halides, allylation of aldehydes, cyanation of aryl halides etc.214 For example, Okano et a/.215 reduced l-chloro-2-nonene to afford 1-nonene and... 

Tetrakis(triphenylphosphine)-palladium(O), 289 Tin(IV) chloride, 300 Trimethylamine N-oxide, 325 Zinc amalgam, 347 Homoallylic alcohols By addition reactions of allyl to carbonyl groups... 

The carbonylation of allyl chloride with a nickel carbonyl catalyst appears to be the first useful example of an organic halide reaction to be reported (6). In alcohol solution at 50 atm pressure and 100°, mixtures of esters of 2- and 3-butenoic acid were obtained in about 50% yield with the 3-isomer predominating. Such high pressures and temperatures are probably not necessary for this reaction, however (7) ... 

A transient orange complex is formed in this reaction, which is very probably chloro-/i3-allylnickel(l 1) dimer, a complex that can be obtained from nickel carbonyl and allyl chloride in an inert solvent (8). The probable mechanism of the carbonylation then becomes clear with the additional facts that bromo-fi3-allylnickel(Il) dimer reacts with carbon monoxide to give unstable bromodicarbonyl(3-butenoyl)nickel(II), which then reacts further with CO to form nickel carbonyl and 3-butenoyl bromide (6). Six separate steps are believed to be involved ... 

---