Triethylamine as catalyst for reaction

Triethylamine as catalyst for reaction of phthalic anhydride with l-phenylalanine, 40, 83 Triethyl phosphite for ethylation of hexachlorocydopentadiene, 43,... 

The biotinylation of amine-dendrimers may be accomplished using either an organic reaction environment or an aqueous medium. For modification of PAMAM dendrimers with a biotinidase resistant biotin compound, Wilbur et al. (1998) performed the reaction in DMF with triethylamine as catalyst (proton acceptor). The following protocol illustrates this type of procedure using the biotinylation reagent NHS-PEG/pbiotin, which closely compares to the biotinidase insensitive compound used in the published procedure. 

Mixtures of regioisomers are frequendy obtained in these reactions.80 The problem is most serious with primary allylic alcohols without a- or p-substituents. Even the 2-arylated products generally rearrange to saturated aldehydes. Ally alcohol itself, when reacted with iodobenzene and triethylamine, with palladium acetate as catalyst, for example, produces a 71 % yield of an 84 16 mixture of 3-phenyl- and 2-phenyl-propanal (equation 28). 

After the reaction reached completion, the solid product was filtered off and identified by NMR spectroscopy and X-ray crystallography. By analyzing the data, the unexpected formation of amide product 40 from benzaldehyde 37C and its corresponding intermediate 39C was revealed. This represented a new transformation pathway, for which only a few related systems have been reported [58-60]. Scheme 14 displays the proposed mechanistic formation of amide product 40, supported by density functional theory (DFT) calculations [61]. In the presence of triethylamine as catalyst, the key intermediate 39C was formed from nitroaldol (Henry) reaction of 2-cyanobenzaldehyde 37C and nitroethane 38. The nitroaldol adduct 39C then underwent internal cyclization (5-exo-dig) to give iminolactone 41,... 

Polymer 149, prepared by ring-opening polymerization (ROMP) of the corresponding functionalized norbornene, provides a clear illustration of the potential of this kind of materials. This resin catalyzes (12% molar) the reaction of linear aliphatic aldehydes with unsaturated ketones to provide 1,4-dicarbonyl compounds (153, Scheme 10.23) and was used for four consecutive cycles without any detectable decrease in performance [358]. A similar dimethylthiazolium structure supported on 2% cross-linked PS-DVB (150) was studied as catalyst for the acyloin condensation of a large variety of aldehydes [364], Catalyst 150 is used in 10 mol.% and the reaction takes place in ethanol at room temperature, with triethylamine as the base, to afford the corresponding a-hydroxyketones in excellent yields. Remarkably, the catalyst can be reused 20 times without losing its activity. 

Trimerization of phenyl isocyanate with triethylamine as catalyst has also been reported and patented. Reactions were carried out at 8000 kg cm and 40°C for 20 h to give 78% of (186) <91JAP03109382>. This contrasts poorly with the 98.8% yield at room temperature in 5 min when tbaf is used. 

However, the addition occurs contrary to the Markovnikov rule under irradiation by ultraviolet light or in the presence of peroxides 1 for instance, allyl-amine hydrochloride or a derivative thereof in alcoholic solution is thiolated by an excess of hydrogen sulfide under UV-irradiation, exclusively (yields up to 57%), to give 3-aminoalkanethiols.2 Addition of hydrogen sulfide is of use in the laboratory only when the reaction can be carried out in the liquid phase and is then preferably effected under the influence of a basic catalyst Dahl-bom,3 for instance, obtained 3-mefcapto-butyric acid from crotonic acid hydrogen sulfide in the presence of diethylamine in a closed vessel at 70° and 4-mercapto-4-methyl-2-pentanone is obtained in 80% yield from mesityl oxide and hydrogen sulfide with triethylamine as catalyst.4... 

The nickel(o)-catalysed oligomerization of butadiene has been further studied. Cyclo-octa-1,5-diene is a major product in hydroxylic solvents, and a minor product in the presence of secondary amines." The oligomerization of butadiene in the presence of nickel(ii)acetylacetonate, triethylamine, alkyl cyanamides, and miscellaneous heterocycles has also been studied, and catalyst systems causing an almost quantitative conversion into trans,trans,trans-, cis,trans,trans-, or cis,cis,trans-cyclododeca-l,5,9-triene were found." The ability of some hydrides, trans-MHX-(PR3)2 (M = Ni or Pd), to act as catalysts for butadiene oligomerization has been found to depend upon the substituent, X, and the solvent the reactions of some cationic palladium hydrides with butadiene was also examined. Unlike other organo-cobalt catalyst systems, CoCUPPhjjj has been found to catalyse the dimerization... 

The full-scale test were performed to find the influence of reaction time, solvent nature, temperature, and reagents feed ration on intrinsic viscosity of polyarylate oximates to find out the optimal reaction conditions for their preparation in accordance with the Scheme 1. It was found that synthesis of polyarylate oximates can be carried out more efficiently in dioxane at 303 K during 40 min. with triethylamine as catalyst and molar ratio DKO/ (CAT) / (DCAIP) = 2/1/1. The reduced specific viscosity r red for a resulting polyarylate oximate was within the range of 0.71-0.81 dl/g. It should be noted that synthesis of polyarylate oximates from phenyl ketoximes in acetone as a solvent proceeded as a heterogeneous proeess and the resulting polymer precipitated from a solution. 

The hemicellulose was modified by reaction with HEMA-Im in DMSO at 45°C with triethylamine as catalyst. HEMA-Im was prepared by the reaction of HEMA with l,r-carbonyldiimidazole in chloroform. The synthetic pathway for the methacrylation is outlined in Scheme 1. 

A -methylglucamine synthesis in the second reaction step in the first step, A -methyllactitolamine was obtained from lactose in a reductive amination reaction similar to that shown in Fig. 2a. Long-chain acyl chlorides were used for the amidation of the A -methyllactitolamine (XVII, Fig. 5) and the reaction was conducted in dimethylformamide (DMF) using triethylamine as catalyst at 5-10°C for 2 h. The yield of pure products XVIII, for which the... 

Reza Nabid et al. [61] used ultrasonic irradiation for the synthesis of lH-pyrazolo[l,2-i7]phthalazine-5,10-diones (46) from the reaction of phthalhydrazide (43), malononitrile or cyanoacetate (44), and aromatic aldehydes (45) using triethylamine as catalyst xmder ethanolic medium. The principal advantage of the protocol is the use of an inexpensive and readily available catalyst, improving yields to 87-98%. Moreover, ethanol as solvent is considered to be relatively environmentally safe (Scheme 13). 

Alkyl- and aryl-pyridazines can be prepared by cross-coupling reactions between chloropyridazines and Grignard reagents in the presence of nickel-phosphine complexes as catalysts. Dichloro[l,2-bis(diphenylphosphino)propane]nickel is used for alkylation and dichloro[l,2-bis(diphenylphosphino)ethane]nickel for arylation (78CPB2550). 3-Alkynyl-pyridazines and their A-oxides are prepared from 3-chloropyridazines and their A-oxides and alkynes using a Pd(PPh3)Cl2-Cu complex and triethylamine (78H(9)1397). 

In recent years there has been some substitution of TDI by MDI derivatives. One-shot polyether processes became feasible with the advent of sufficiently powerful catalysts. For many years tertiary amines had been used with both polyesters and the newer polyethers. Examples included alkyl morpholines and triethylamine. Catalysts such as triethylenediamine ( Dabco ) and 4-dimethyla-minopyridine were rather more powerful but not satisfactory on their own. In the late 1950s organo-tin catalysts such as dibutyl tin dilaurate and stannous octoate were found to be powerful catalysts for the chain extension reactions. It was found that by use of varying combinations of a tin catayst with a tertiary amine... 

The treatment of enamines with acid halides which possess no a hydrogens results in the simple acylation of the enamine (7,12,62-67). If the acid halide possesses an a hydrogen, however, ketenes are produced in situ through base-catalyzed elimination of hydrogen chloride from the acid halide. The base catalyst for this reaction may be the enamine itself or some other base introduced into the reaction mixture such as triethylamine. However, if the ketene is produced in situ instead of externally, there still remains the possibility of a side reaction between the acid halide and the enamine other than the production of ketene (67,84). 

A mixture of monolauryl phosphate sodium salt and triethylamine in H20 was treated with glycidol at 80°C for 8 h to give 98% lauryl 2,3-dihydro-xypropyl phosphate sodium salt [304]. Dyeing aids for polyester fibers exist of triethanolamine salts of ethoxylated phenol-styrene adduct phosphate esters [294], Fatty ethanolamide phosphate surfactant are obtained from the reaction of fatty alcohols and fatty ethanolamides with phosphorus pentoxide and neutralization of the product [295]. A double bond in the alkyl group of phosphoric acid esters alter the properties of the molecule. Diethylethanolamine salt of oleyl phosphate is effectively used as a dispersant for antimony oxide in a mixture of xylene-type solvent and water. The composition is useful as an additive for preventing functional deterioration of fluid catalytic cracking catalysts for heavy petroleum fractions. When it was allowed to stand at room temperature for 1 month it shows almost no precipitation [241]. 

To explore the feasibility of these polymers as a pendant delivery drug delivery system, 5-fluorouracil activated by 1,1,1,3,3,3-hexamethyl disilazane was coupled to the phosphite via the Todd reaction as shown in Scheme 2. Briefly, the polymer (PPU-7) solution in dimethylacetamide was mixed with a 1 1 v/v solution of carbon tetrachloride and methylene chloride containing 0.5 volume percent of triethylamine (TEA) as catalyst. The activated drug dissolved in methylene chloride was added slowly into the mixture and allowed to react for 48 hours at room temperature. The product was isolated by precipitation into carbon tetrachloride. 

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