Elimination formation

A convenient laboratory method for the preparation of BCl is by the reaction of AlCl and BF or BF (47—49). More recently a patent describing the preparation of BCl by halogenating B(OH)2 or esters of B(OH)2 using an excess of the oxychloride of S or P in the presence of a dessicant and catalytic amounts of Fe, Co, or Ni, at temperatures below 100°C was issued (50). This process eliminates formation of carbonic dichloride [75-44-5] ... 

Bischler-Napieralski reaction conditions can be attributed, again, to the destabilizing ability of the trifluoromethyl group to the cationic transition state of the acid catalyzed elimination. Formation of compound 29 was ultimately accomplished by base catalyzed methanol elimination-conditions conditions that are quite unusual for isoquinoline formation. 

Michael addition of the enamine to the 1,3-enyne double bond (intermediate 151) and subsequent intramolecular attack of the triple bond by the amino group (intermediate 152) with the r XH elimination (formation of 2,6-isomer 148). 

The discovery of nitrosamine contaminants In some pesticides has led to a major technological effort to prevent, reduce or eliminate formation of these Inadvertent Impurities In pestlcldp formulations. Although the nitrosamine... 

The damage potential of TKPP fluids was further reduced by the addition of multivalent cations. When these salts were added at approximately their solubility limit in TKPP solutions, damage decreased, lending additional credence to the observation that the addition potassium ions alone is not sufficient to completely eliminate formation damage. 

A nickel(O) complex catalyzes insertion of alkynes into cyclobutanones (Equation (79)).437 Formation of metalla-cycle 194 via oxidative cyclization of an alkyne with the carbonyl group of a cyclobutanone followed by /3-carbon elimination (formation of metallacycle 195) and reductive elimination are postulated for the mechanism (Scheme 92). 

Organic elimination (formation of an ether from an alcohol in the presence of an acid). 

Accordingly, it can be assumed that the peroxoiron(III) intermediate 61 (see also 9, Fig, 3) acts as a nucleophile on the aldehyde 59 to generate the adduct 62 which eliminates formate to give the hydroxyiron(IV) intermediate 40 and the... 

The gas-phase unimolecular pyrolysis of 2,4-dimethylpentane-2,4-diol has been found to occur by eliminative formation of acetone, isobutene, and H20 via a concerted six-membered cyclic transition state (Scheme 10).69 Single-pulse shock tube studies of the eliminative decomposition of ethoxy compounds have also been reported.70... 

The fluorine containing 7t-exTTF 550 was obtained in the 1,3-dipolar cycloaddition of DMAD to dithiocarboxylic moiety of the dithiocrotonate 549 and subsequent reaction of the resulting intermediate ylide with the starting 549 as a Michael acceptor in an addition-elimination process followed by ethyl bromide elimination. Formation of the second 1,3-dithiole moiety in 550 was connected with the consecutive cycloaddition followed by ethyl bromide elimination (Equation 71) <2003CEJ4324>. 

Widely used for foaming HDPE, PP, HIPS, PVC, EVA, acetal, acrylic, and PPO-based plastics. Decomposes at 400°-415°F (204°-213°C). Non-plateout grades are available to eliminate formation of cyanuric acid, which can attack molds. 

Hofmann elimination Formation of alkenes from quaternary ammonium salts. 206... 

Additional experiments were performed using the same procedure as above, except the system was cooled from 450 C to room temperature in pure CO2. Other runs were made in which the temperature at which the system was exposed to CO2/H2 was varied from 400 to 600 C. Cooling in CO2/H2 from 450 C to 25 C enhanced bicarbonate formation and eliminated formate/methoxide formation. 

Guzaev and Lonnberg [221] have proposed an original diethyl 2,2-bis(hydroxymethyl)malonate anchor (Figure 19.11) on LCAA-CPG (up to 60 xmolg 1) that is cleavable under basic conditions via a retroaldol reaction followed by P-elimination. Formation of the 3 -phosphate takes about 20 min in concentrated ammonia and progressively longer under milder conditions 3h in 0.05 M potassium carbonate in methanol and 10 h in 50% ethanolic ethylenedi-... 

In virtue of the characteristic small dimensions and the applied low flow rates, the flow is laminar in perfusion based microfluidic cell culture chips. Consequently, convection only exists in the direction of the applied flow (x-direction), whereas in the directions perpendicular to the flow (y- and z-direction) only diffusion contributes to mass transfer. This is schematically illustrated in Fig. 2b, depicting a pronounced flow in x-direction. Due to short distances, mass transfer by diffusion is sufficiently effective in providing nutrients and removing metabolic waste during continuous perfusion, eliminating formation of concentration gradients, and hence accumulation of metabolic waste. Furthermore, the small dimensions of microfluidic cell... 

A complication of the Thorex process is appearance of a second organic phase at high concentrations of thorium nitrate and nitric acid. To obtain reproducible separation, Thorex process systems are designed to stay below the thorium concentrations at which the second organic phase forms. Figure 10.27 shows these conditions for -dodecane diluent and Ultrasene at SO C. Siddall [SI4] has pointed out that substitution of triamyl phosphate for TBP would essentially eliminate formation of a second organic phase with thorium. 

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