Acetamide catalyst

Chapter III. 1 Heptene (111,10) alkyl iodides (KI H3PO4 method) (111,38) alkyl fluorides (KF-ethylene glycol method) (111,41) keten (nichrome wire method) (111,90) ion exchange resin catalyst method for esters (111,102) acetamide (urea method) (111,107) ethyl a bromopropionate (111,126) acetoacetatic ester condensation using sodium triphenylmethide (111,151). 

Water hydroly2es pure diketene only slowly to give acetoacetic acid [541-50-4] which quickly decomposes to acetone and carbon dioxide, but increasing the pH or adding catalysts (amines, palladium compounds) increases the rate of hydrolysis. The solvolysis of diketene in ammonia results in aceto acetamide [5977-14-0] if used in stoichiometric amounts (99), and P-arninocrotonarnide [15846-25-0] if used in excess (100). 

Similar disproportionation reactions are catalyzed by organic catalysts, eg, adiponittile, pyridine, and dimethyl acetamide. Methods for the redistribution of methyUiydridosilane mixtures from the direct process have been developed to enhance the yield of dimethylchlorosilane (158). 

Sulfation by sulfamic acid has been used ia the preparation of detergents from dodecyl, oleyl, and other higher alcohols. It is also used ia sulfating phenols and phenol—ethylene oxide condensation products. Secondary alcohols react ia the presence of an amide catalyst, eg, acetamide or urea (24). Pyridine has also been used. Tertiary alcohols do not react. Reactions with phenols yield phenyl ammonium sulfates. These reactions iaclude those of naphthols, cresol, anisole, anethole, pyrocatechol, and hydroquinone. Ammonium aryl sulfates are formed as iatermediates and sulfonates are formed by subsequent rearrangement (25,26). 

With hydrogen sulfide at 500—600°C, monochlorotoluenes form the corresponding thiophenol derivatives (30). In the presence of palladium catalysts and carbon monoxide, monochlorotoluenes undergo carbonylation at 150—300°C and 0.1—20 MPa (1—200 atm) to give carboxyHc acids (31). Oxidative coupling of -chlorotoluene to form 4,4 -dimethylbiphenyl can be achieved in the presence of an organonickel catalyst, generated in situ, and zinc in dipolar aprotic solvents such as dimethyl acetamide (32,33). An example is shown in equation 4. 

Pd-catalyzed asymmetric allylic alkylation is a typical catalytic carbon-carbon bond forming reaction [ 126 -128]. The Pd-complex of the ligand (R)-3b bearing methyl, 2-biphenyl and cyclohexyl groups as the three substituents attached to the P-chirogenic phosphorus atom was found to be in situ an efficient catalyst in the asymmetric allylic alkylation of l-acetoxy-l,3-diphenylprop-2-en (4) with malonate derivatives in the presence of AT,0-bis(trimethylsilyl)acetamide (BSA) and potassium acetate, affording enantioselectivity up to 96% and quantitative... 

Scheme 9.14 Decarbonylation of diazo-acetamides with catalyst 43-NHC...

The original catalyst was Rh2(02CCH3)4, but other carboxylates such as nonafluo-robutanoate and amide anions, such as those from acetamide and caprolactam, also have good catalytic activity.199... 

Amides and sulfonamides undergo intramolecular chemistry to form aryl amides and aryl sulfonamides (Equations (17)—(19)) in the presence of palladium catalysts ligated by arylphos-phines.35,89 Initially, complexes of P(furyl)3 and P(o-tol)3 were most effective catalysts, but complexes of Hayashi s MOP and van Leeuwen s DPEphos and xantphos have lately been shown to be more active.90 In the presence of catalysts containing one of these ligand systems, five-, six-, and seven-membered rings were formed from halogenated benzamides or from substrates containing an acetamide, an A-carbobenzyloxy, or a t-butylcarbamate substituent tethered to the aryl halide (Equations (18) and (19)) ... 

Borohydride reduction of NiCl2 in dimethylformamide or dimethyl-acetamide leads to very active catalysts, thought to be homogeneous, for hydrogenation of monoolefins, unsaturated fats, cyclic dienes to monoenes, and saturated aldehydes and ketones (165, 538, 539). Cobaltous chloride systems have also been used (540). 

Stereoselective inns-cyclopropanation. Rhodium(II) carboxylates are generally the preferred catalysts for cyclopropanation of alkenes with diazoacetates (7,313 9,406,10,340) even though they show only low tram-selectivity. The tram-selectivity can be markedly enhanced by use of rhodium(II) acetamide. Use of rhodium(II) 2,4,6-triarylbenzoates favors ds-stereoselectivity.1... 

Aliquat is an efficient catalyst for the acetoacetylation of amines by diketene. The initially formed amides react with an excess of the diketene to form, after cyclization of the secondary product, 1-substituted 3-acetyl-4-hydroxy-6-methylpyrid-2-ones [39]. Amides react under similar conditions with diketene to form A-acyl aceto-acetamides, which react further with a second molecule of diketene to yield, after cleavage of the A-acyl group, 3-acetyl-4-hydroxy-6-methylpyrid-2-one [39]. 

A heterogeneous and recyclable palladium catalyst, Pd/A10(OH), is excellent for the racemization of primary amines. We have demonstrated successful DKR of various primary amines by combining the palladium catalyst and a lipase to produce the corresponding (/ )-acetamides in high yields and in high optical purities. Tables 4.3 and 4.4 show the results of the DKR of benzyhc and aliphatic primary amines. 

A facile method for the oxidation of nucleoside H-phosphonates to phosphates has been developed with BTSP and N,0-bis(trhnethylsilyl)acetamide, MeC(NSiMe3)OSiMe3, in the presence of Me3Si0S02CF3 as a catalyst (equations 67 and 68) °. 

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