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Bromides carbonylation

Vinyllithiums of type 663 (R2 = R3 = H) reacted with primary alkyl bromides, carbonyl compounds, carbon dioxide, DMF, silyl chlorides, stannyl chlorides, disulfides and phenylselenyl bromide142,970-979. Scheme 173 shows the synthesis of dihydrojasmone 669 from the corresponding 1,4-diketone. a-(Phenylsulfanyl)vinyllithium 665, prepared from phenyl vinyl thioether, reacted with hexanal and the corresponding adduct 666 was transformed into its acetoacetate. This ester 667 underwent a Carrol reaction to produce the ketone 668, which was transformed into the cyclopentenone 669 by deprotection either... [Pg.249]

Oxidative insertion into the aryl bromide, carbonylation, and nucleophilic attack on the carbonyl group with eUmination of Pd(0) form the catalytic cycle. No doubt the palladium has a number (1 or 2 ) of phosphine ligands complexed to it during the reaction and these keep the Pd(0) in solution between cycles. [Pg.478]

Carbonochloridic acid, 2,2.2-lrichloroelhyl ester Carbonottiioicdictiloride Carbonothioic dihydrazide Carbon oxyseienide Carbon oxysuilide Carbon suboxide Carbonyl bromide Carbonyl chloride... [Pg.190]

Carbonyl bromide Carbonyl chloride Carbonyl chloride fluoride Carbonyl dicyanide A/,A/ -Carbonyldiimidazole Carbonyl fluoride... [Pg.221]

Dimethyl sulfoxidelhydrogen bromide Carbonyl from methylene groups... [Pg.354]

The only common synthons for alkynes are acetylide anions, which react as good nucleophiles with alkyl bromides (D.E. Ames, 1968) or carbonyl compounds (p. 52, 62f.). [Pg.36]

Finally (d + aV dditions of 1-alkenyl and 1-alkynyl anions to carbonyl groups should be mentioned. Examples are the addition of vinylmagnesium bromide to ketones e.g. in the first step of Torgov s steroid synthesis (I.N. Nazarov, 1957), and the famous alkynylation of... [Pg.62]

TT-Allylpalladium chloride (36) reacts with the nucleophiles, generating Pd(0). whereas tr-allylnickel chloride (37) and allylmagnesium bromide (38) reacts with electrophiles (carbonyl), generating Ni(II) and Mg(II). Therefore, it is understandable that the Grignard reaction cannot be carried out with a catalytic amount of Mg, whereas the catalytic reaction is possible with the regeneration of an active Pd(0) catalyst, Pd is a noble metal and Pd(0) is more stable than Pd(II). The carbon-metal bonds of some transition metals such as Ni and Co react with nucleophiles and their reactions can be carried out catalytic ally, but not always. In this respect, Pd is very unique. [Pg.17]

Another feature of the Pd—C bonds is the excellent functional group tolerance. They are inert to many functional groups, except alkenes and alkynes and iodides and bromides attached to sp carbons, and not sensitive to H2O, ROH, and even RCO H. In this sense, they are very different from Grignard reagents, which react with carbonyl groups and are easily protonated. [Pg.17]

Usually, iodides and bromides are used for the carbonylation, and chlorides are inert. I lowever, oxidative addition of aryl chlorides can be facilitated by use of bidcntatc phosphine, which forms a six-membered chelate structure and increa.scs (he electron density of Pd. For example, benzoate is prepared by the carbonylation of chlorobenzene using bis(diisopropylphosphino)propane (dippp) (456) as a ligand at 150 [308]. The use of tricyclohexylphosphine for the carbonylation of neat aryl chlorides in aqueous KOH under biphasic conditions is also recommended[309,310]. [Pg.190]

Heteroaromatic esters such as 493 and amides are produced by the carbo-nylation of heterocyclic bromides[347,348]. Even dichloropyrazine (494) and chloropyridine are carbonylated under somewhat severe conditions (120 C, 40 atm)[349]. The carbonylation of trifluoroacetimidoyl iodide (495) proceeds under mild conditions, and can be used for the synthesis of the trifluoromethyl-glycine derivatives 496 and 497(350]. [Pg.196]

Carbonylation of halides in the presence of primary and secondary amines at I atm affords amides[351j. The intramolecular carbonylation of an aryl bromide which has amino group affords a lactam and has been used for the synthesis of the isoquinoline alkaloid 498(352], The naturally occurring seven-membered lactam 499 (tomaymycin, neothramycin) is prepared by this method(353]. The a-methylene-d-lactam 500 is formed by the intramolecular carbonylation of 2-bromo-3-alkylamino-l-propene(354]. [Pg.196]

The o-keto ester 513 is formed from a bulky secondary alcohol using tricy-clohexylphosphine or triarylphosphine, but the selectivity is low[367-369]. Alkenyl bromides are less reactive than aryl halides for double carbonyla-tion[367], a-Keto amides are obtained from aryl and alkenyl bromides, but a-keto esters are not obtained by their carbonylation in alcohol[370]. A mechanism for the double carbonylation was proposed[371,372],... [Pg.199]

It is known that tr-allylpalladium acetate is converted into allyl acetate by reductive elimination when it is treated with CO[242,243]. For this reason, the carbonylation of allylic acetates themselves is difficult. The allylic acetate 386 is carbonylated in the presence of NaBr (20-50 mol%) under severe conditions, probably via allylic bromides[244]. However, the carbonylation of 5-phenyl-2,4-pentadienyl acetate (387) was carried out in the presence of EtiN without using NaBr at 100 °C to yield methyl 6-phenyl-3,5-hexadienoate (388)[245J. The dicarbonylation of l,4-diacetoxy-2-butene to form the 3-hexenedioate also proceeds by using tetrabutylphosphonium chloride as a ligand in 49% yield[246]. [Pg.341]

D ib enzy lamin o) in dol-1 -y Imagnes ium bromide l-(Bcnzyloxycarbonyl)pyrrolidine-2-carbonyl chloride 44 [7]... [Pg.114]

Other Complexes. Several other classes of organonickel complexes are known. AHyl bromide and nickel carbonyl react to give a member of the TT-aHyl system [12012-90-7], [7T-C3H3NiBr]2 (100). Tris(r -ethene)nickel [50696-82-7] reacts with acetylene and l,2-bis(diisopropylphosphino)ethane to... [Pg.12]


See other pages where Bromides carbonylation is mentioned: [Pg.392]    [Pg.87]    [Pg.345]    [Pg.382]    [Pg.338]    [Pg.156]    [Pg.338]    [Pg.156]    [Pg.685]    [Pg.7180]    [Pg.686]    [Pg.392]    [Pg.87]    [Pg.345]    [Pg.382]    [Pg.338]    [Pg.156]    [Pg.338]    [Pg.156]    [Pg.685]    [Pg.7180]    [Pg.686]    [Pg.31]    [Pg.44]    [Pg.46]    [Pg.48]    [Pg.122]    [Pg.139]    [Pg.316]    [Pg.199]    [Pg.200]    [Pg.457]    [Pg.573]    [Pg.236]    [Pg.542]    [Pg.166]    [Pg.239]    [Pg.312]   


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Alcohols carbonyl bromide fluoride

Aryl bromides carbonylation

Benzyl bromide carbonylation

Carbonyl bromide

Carbonyl bromide

Carbonyl bromide analysis

Carbonyl bromide chloride

Carbonyl bromide chloride decomposition

Carbonyl bromide chloride from phosgene

Carbonyl bromide chloride hydrolysis

Carbonyl bromide chloride metals

Carbonyl bromide chloride organic reactions

Carbonyl bromide chloride reaction with

Carbonyl bromide chloride synthesis

Carbonyl bromide cyanide

Carbonyl bromide fluoride

Carbonyl bromide fluoride decomposition

Carbonyl bromide fluoride metals

Carbonyl bromide fluoride reaction with

Carbonyl bromide fluoride synthesis

Carbonyl bromide groups, introduction

Carbonyl bromide iodide

Carbonyl bromide preparation

Carbonyl bromide properties

Carbonyl bromide, decomposition

Carbonyl bromides compounds

Carbonyl dibromide bromide

Carbonylations palladium bromide

Carbonylative annulations, 3- bromide

Copper bromide carbonyl compounds

Magnesium Bromide carbonyl condensations

Magnesium bromide allylstannane reaction with carbonyl compounds

Molybdenum bromide carbonyl

Organic compounds carbonyl bromide chloride

Oxidative carbonylations palladium®) bromide

Phenylethyl bromide, carbonylation

Ruthenium complexes carbonyl bromides

Selenenyl bromide, 2-pyridyldehydrogenation carbonyl compounds

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