Zinc Chloride related reagents

Zinc chloride was used as a catalyst in the Friedel Crafts benzylation of benzenes in the presence of polar solvents, such as primary alcohols, ketones, and water.639 Friedel-Crafts catalysis has also been carried out using a supported zinc chloride reagent. Mesoporous silicas with zinc chloride incorporated have been synthesized with a high level of available catalyst. Variation in reaction conditions and relation of catalytic activity to pore size and volume were studied.640 Other supported catalytic systems include a zinc bromide catalyst that is fast, efficient, selective, and reusable in the /wa-bromination of aromatic substrates.641... [Pg.1202]

Arene(tricarbonyl)chromium complexes, 19 Nickel boride, 197 to trans-alkenes Chromium(II) sulfate, 84 of anhydrides to lactones Tetrachlorotris[bis(l,4-diphenyl-phosphine)butane]diruthenium, 288 of aromatic rings Palladium catalysts, 230 Raney nickel, 265 Sodium borohydride-1,3-Dicyano-benzene, 279 of aryl halides to arenes Palladium on carbon, 230 of benzyl ethers to alcohols Palladium catalysts, 230 of carboxylic acids to aldehydes Vilsmeier reagent, 341 of epoxides to alcohols Samarium(II) iodide, 270 Sodium hydride-Sodium /-amyloxide-Nickel(II) chloride, 281 Sodium hydride-Sodium /-amyloxide-Zinc chloride, 281 of esters to alcohols Sodium borohydride, 278 of imines and related compounds Arene(tricarbonyl)chromium complexes, 19... [Pg.372]

Related Reagents. Dibromomethane-Zinc-Titanium(IV) Chloride Methylenetriphenylphosphorane. [Pg.284]

Besides PAN, numerous other pyridylazo reagents have been proposed for spectrophotometric determination of Zn. This group comprises the related reagent PAR [14,47-50]. The complex of Zn with PAR is extracted with chloroform in the presence of cetyldimethylbenzylammonium chloride (e = 9.1-10 ) [51]. Zinc (and other heavy metals) are preconcentrated on a cation-exchanger, modified with PAR [52]. Bromo- and chloro-derivatives of pyridylazo compounds have become a basis for more sensitive methods, e.g., 5-Br-PADAP, (formula 4.3) [53,54], 2-(3,5-dibromo-2-pyridylazo)-5-diethylaminophenol (3,5-diBr-PADAP) (e = 1.3-10 at 570 nm) [55], and other bromine derivatives [56]. Application of the chlorine derivatives of pyridylazo reagents has been reviewed [53,57,58]. [Pg.469]

The mechanism of the Fischer indole synthesis is related to that of the benzidine rearrangement.91 This synthesis consists of the preparation of indole and substituted indoles by heating the phenylhydrazones or substituted phenylhydrazones of aldehydes, ketones, or oxo acids with reagents such as zinc chloride, or mineral acids that lead to elimination of ammonia, thus 92... [Pg.1073]

Related Reagents. See entries for other Lewis Acids, e.g. Zinc Chloride, Aluminum Chloride, 1Uanium(IV) Chloride-, also see entries for Boron Trifluoride (and combination reagents), and combination reagents employing Boron Trifluoride Etherate, e.g. ButyUithium—Boron Trifluoride herate, Cerium(III) Acetate-Boron Trifluoride Etherate, Lithium Aluminum Hydride-Boron Trifluoride Etherate, Methylcopper-Boron Trifluoride Etherate,... [Pg.39]

Related Reagents. Cerium(III) Chloride Nickel Boride Potassium Triisopropoxyborohydride Sodium Cyanoboro-hydride Sodium Triacetoxyborohydride Cobalt Boride Lithium Borohydride Lithium Aluminium Hydride Zinc Borohydride Tetramethylammonium Triacetoxyborohydride. [Pg.413]

Related Reagents. Diphenylsilane-Tetrakis(triphenylphos-phine)palladium(0)-Zinc Chloride. [Pg.472]

Related Reagents. Iron Tin Zinc Amalgam Zinc-Zinc Chloride. [Pg.556]

Related Reagents. Copper(II) Chloride Copper(II) Chloride-Copper(II) Oxide lodine-Copper(II) Chloride Copper(I) Chloride-Oxygen Copper(I) Chloride-tetrabutylammonium Chloride Copper(I) Chloride-Sulfur Dioxide lodine-Alutninum(III) Chloride-Copper(II) Chloride lodine-Copper(I) Chloride-Copper(II) Chloride Methylmagnesium lodide-Copper(I) Chloride Palladium(II) Chloride-Copper(I) Chloride Palladium(II) Chloride-Copper(II) Chloride Phenyl Selenocyanate-Copper(II) Chloride nyl-magnesium Chloride-Copper(I) Chloride Zinc-Copper(I) Chloride. [Pg.209]

The use of zinc chloride and related substances, or acetic anhydride, is a common feature of many reactions of alkylpyridines. The first type of reagent probably exercises a generalized acid catalysis, augmenting the reactivity of alkyl groups by coordination with the nitrogen atom. Acetic anhydride... [Pg.331]

Alkenes react with acyl halides or acid anhydrides in the presence of Lewis acid catalysts. The reaction works better with cyclic alkenes than for acyclic ones. A mechanistically significant feature of this reaction is the kinetic preference for formation of unsaturated ketones. Mechanistic studies using acetic anhydride and zinc chloride as the reagent system are consistent with a two-step mechanism in which the location of the double bond in the product is determined by ease of deprotonation of the initial adduct. A related reaction occurs when alkenes react... [Pg.464]

Related Reagents. Lithium Chloride-Diisopropylethyl-amine Lithium Chloride-Hexamethylphosphoric Triamide Zinc Chloride. [Pg.249]

Related Reagents. Bis(trichloromethyl) Carbonate Phos-phorus(V) Oxide Phosphorus Oxychloride-Zinc(II) Chloride Thionyl Chloride p-Tolyl Vinyl Sulfoxide Trichloromethyl Chloroformate. [Pg.349]

Related Reagents. Dibromomethane-Zinc-Titanium(IV) Chloride Diiodomethane-Zinc-Titanium(IV) Chloride 4R, 5i )-2,2-Dimethyl-4,5-bis(hydroxydiphenylmethyl)-l,3-di-oxolane-Titanium(IV) Chloride Lithium Aluminum Hydride-Titanium(IV) Chloride Titanium(IV) Chloride-Diazabicyclo-[5.4.0]undec-7-ene Titanium(IV) Chloride-2,2,6,6-Tetramethyl-piperidine Titanium(IV) Chloride-Triethylaluminum Titanium-(IV) Chloride-Zinc. [Pg.388]

Related Reagents. Magnesium Bromide Zinc Chloride Zinc Iodide. [Pg.471]

Related Reagents. Aluminum Chloride Diphenylsilane-Tetrakis(triphenylphosphine)palladium(0)-Zinc Chloride Phos-phorus(in) Chloride-Zinc(II) Chloride Phosphorus Oxychlo-ride-Zinc(II) Chloride Tin(rV) Chloride Tin(IV) Chloride-Zinc Chloride Titanium(IV) Chloride Zinc Bromide. [Pg.477]

Related Reagents. Zinc Bromide Zinc Chloride. [Pg.481]

A related preparation of diethyl 3-oxoalkyIphosphonates uses a zinc-mediated approach from dietliyl 2-bromoethylphosphonate. Thus, treatment of diethyl 2-bromoethylphosphonate with zinc dust in THF at 30°C affords the corresponding alkylzinc bromide in 90% yield. The addition of the soluble CuCN2LiCl at 0°C transmetallates the intermediate zinc compound to the copper compound. This copper-zinc reagent reacts with acyl chlorides in THF at 0°C to provide the corresponding diethyl 3-oxoalkyIphosphonates in high yields (84-96%, Scheme 7.57). ... [Pg.356]

Angelini described the preparation of dihydro- 1,4-benzothiazine and related compounds from analogous esters by a two-stage reduction using tin and HC1 or lithium aluminum hydride.129 It is interesting to compare the reaction of 2-nitrophenol with similar reagents to produce benzooxazine derivatives. 2-Nitrophenol reacts with a-bromoethyl acetate, and the adduct is cyclized with zinc and ammonium chloride to the hydroxamic derivative 85.130 The adduct with phenacyl chloride has been similarly cyclized under a variety of conditions.131,132... [Pg.160]