Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Silver acetate alkylation with

As esters the alkyl halides are hydrolysed by alkalis to alcohols and salts of halogen acids. They are converted by nascent hydrogen into hydrocarbons, by ammonia into amines, by alkoxides into ethers, by alkali hydrogen sulphides into mercaptans, by potassium cyanide into nitriles, and by sodium acetate into acetic esters. (Formulate these reactions.) The alkyl halides are practically insoluble in water but are, on the other hand, miscible with organic solvents. As a consequence of the great affinity of iodine for silver, the alkyl iodides are almost instantaneously decomposed by aqueous-alcoholic silver nitrate solution, and so yield silver iodide and alcohol. The important method of Ziesel for the quantitative determination of alkyl groups combined in the form of ethers, depends on this property (cf. p. 80). [Pg.98]

A clean twofold Heck coupling of unsubstituted butadiene 46 (R = H) in the 1- and 4-positions has not been reported. However, the initial carbopalladation product from 46 (R = H) and an in situ formed arylpalladium halide, the cr-allylpalladium halide 47 equilibrating with the corresponding 7r-allylpalladium halide, can efficiently be trapped with the anion formed by arylation of malononitrile or cyanoacetate to give 48, a product of reductive 1,4-arylation-alkylation of 1,3-butadiene 46 (R = H)." /3-Hydride elimination from the intermediate 47 (R H) can be accomplished when the reaction is carried out in the presence of silver acetate or thallium acetate, leading to the... [Pg.318]

This methodology was applied to the asymmetric synthesis of (—)-sedamine (Scheme 10.20). An imine produced in situ from o-anisidine and methyl-5-oxopen-tanoate was alkylated with an enol silane in the presence of silver acetate as catalyst,... [Pg.295]

Furthermore, e t/o-7-alkylated 7-bromobicyclo[4.1.0]heptanes unexpectedly underwent acetolysis when treated with a suspension of silver acetate and silver tetrafluroborate in acetic acid and gave stereospecifically exo-7-acetoxy-eM[Pg.1306]

The reverse CS->CO transformation of A -alkyl thioacctamido sugars has been achieved by treatment with silver acetate.186... [Pg.72]

Diazocarbonyl and diazophosphoryl compounds react with silver (ii) oxide easily (Schollkopf and Rieber, 1969). In diazomethane, both H-atoms are replaced with silver acetate in a mixture of ether and pyridine (Blues et al., 1974). Mono- and disilver diazo compounds are often used for C-alkylation (see examples given by Regitz and Maas, 1986, Sect. 14.6). [Pg.386]

Many arylations are assisted by functional groups that promote ortho-metallation. Thus, for example, acetanihdes react with arylsilanes at the ortho position via pal-ladacycles 78 and 79 to form derivatives 80 (Scheme 11.27) [84]. Mechanistically, this transformation is similar to a cross-coupling reaction, in which the oxidative addition step is replaced by the ortho-metallation, although in this case the Pd(0) intermediate must be oxidized in situ to generate the reactive Pd(ll) species. Unsubstituted benzylamines and N-methylbenzylamine are ortho-arylated with Pd(OAc)2 in the presence of trifluoroacetic acid (TFA) and silver acetate [85], and a mechanism which differs from the usual Pd(0)/Pd(II) catalytic cycle was suggested for this. Ortho-alkylation was also observed in the palladium-catalyzed... [Pg.380]

Pioneering work on the use of a directing group in palladium-catalyzed C-H alkylation was disclosed by Tremont and coworkers. Acetanilides [7] and aldimines [8] were successfully ortho-metaUated using stoichiometric palladium acetate and then reacted with alkyl or allyl halides. The reaction also proceeded with catalytic amounts of palladium when silver acetate was added to regenerate Pd(OAc)2 (Scheme 19.3). [Pg.1429]

Other apphcations of sodium bromide iaclude use ia the photographic iadustry both to make light-sensitive silver bromide [7785-23-1] emulsions and to lower the solubiUty of silver bromides during the developing process use as a wood (qv) preservative in conjunction with hydrogen peroxide (14) as a cocatalyst along with cobalt acetate [917-69-1] for the partial oxidation of alkyl side chains on polystyrene polymers (15) and as a sedative, hypnotic, and anticonvulsant. The FDA has, however, indicated that sodium bromide is ineffective as an over-the-counter sleeping aid for which it has been utilized (16). [Pg.189]

The first asymmetric synthesis of (-)-monomorine I, an enantiomer of the natural alkaloid, by Husson and co-workers starts with the chiral 2-cyano-6-oxazolopiperidine synthon (385) prepared from (-)-phenylglycinol (384), glu-taraldehyde (383), and KCN (443). Alkylation of 385 with an iodo ketal led to the formation of a single product (386). The cyano acetal (386) was treated with silver tetrafluoroborate and then zinc borohydride to afford a 3 2 mixture of C-6 epimeric oxazolidine (387) having the (2S) configuration. Reaction of 387 with... [Pg.268]

The equivalence of sulfur and oxygen in this ring system carries over to NSAIDs as well. Preparation of the sulfur analogue of isoxepac (6-4) starts with the alkylation of thiophenol (27-1) with benzyl chloride (26-1). Cyclization of the intermediate thioether (27-2) then affords the homothioxanthone (27-3). The carboxyl side chain is then extended by means of the Amdt-Eistert homologation reaction. The acid is thus hrst converted to its acid chloride by means of thionyl chloride. Reaction with excess diazomethane leads to the diazoketone (27-4). Treatment of that intermediate with silver benzoate and triethylamine leads the ketone to rearrange to an acetic acid. There is thus obtained tiopinac (27-5) [28]. [Pg.530]

Methyl-2-diphenylphosphino-3-(l -isoquinolyl)indole with pallada-cycle derived from dimethyl-1-naphthyl ethylamine and potassium hexa-fluorophosphate yields chelate 310 (97T4035). With [(r)3-PhCH = CH = CHPh)Pd( j.-Cl)]2, allyl 311 follows in the presence of silver tetrafluor-oborate. Addition of ligands 312 (R = R1 = H, Me) to [(r 3-PhCHCHCHPh)Pd (Cl) ]2 under conditions of allylic alkylation of 1,3-diphenylprop-2-enyl acetate with dimethyl malonate leads to the formation of P,N-chelates 313 (R = R1 = H, Me), the active species of the catalytic reaction (00T(A)4753). [Pg.448]

Cyano compounds liquid crystals, 12, 278 in silver(III) complexes, 2, 241 Cyanocuprates, with copper, 2, 186 Cyano derivatives, a-arylation, 1, 361 Cyanosilanes, applications, 9, 322 Cyclic acetals, and Grignard reagent reactivity, 9, 53 Cyclic alkenes, asymmetric hydrosilylation, 10, 830 Cyclic alkynes, strained, with platinum, 8, 644 Cyclic allyl boronates, preparation, 9, 196 Cyclic allylic esters, alkylation, 11, 91 Cyclic amides, ring-opening polymerization, via lanthanide catalysis, 4, 145... [Pg.88]

Palladium/silver-catalyzed Heck reactions have usually involved vinyl or aryl halides and alkenes, but these reaction conditions were also extended to allenes. Indeed, Zenner and Larock65 showed that simple alkyl allenes readily reacted with aryl and vinyl iodide derivatives in the presence of palladium acetate or chloride and silver phosphate. Moreover, the reaction could be rendered asymmetric using chiral ligands the best one was a bisoxazolidine derivative (Scheme 10.37). [Pg.302]


See other pages where Silver acetate alkylation with is mentioned: [Pg.246]    [Pg.216]    [Pg.192]    [Pg.116]    [Pg.339]    [Pg.722]    [Pg.131]    [Pg.483]    [Pg.1025]    [Pg.14]    [Pg.111]    [Pg.64]    [Pg.124]    [Pg.68]    [Pg.232]    [Pg.64]    [Pg.16]    [Pg.339]    [Pg.246]    [Pg.104]    [Pg.358]    [Pg.207]    [Pg.7]    [Pg.60]    [Pg.470]    [Pg.157]    [Pg.221]    [Pg.310]    [Pg.310]    [Pg.217]    [Pg.1188]    [Pg.63]    [Pg.121]    [Pg.782]    [Pg.694]   
See also in sourсe #XX -- [ Pg.16 ]




SEARCH



Acetals alkyl

Alkyl acetates

Silver alkylation with

© 2024 chempedia.info