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2‐d‐Acrylamide was synthesized via the 2‐step procedure starting from acrylonitrile and deuterium oxide. This procedure affords 2‐d‐acrylamide in 99.9% chemical purity and 98.4% isotopic enrichment. [ABSTRACT FROM AUTHOR]

ABSTRACT Bifunctional tertiary phosphines with hydrogen-bonding functionalities have recently received a considerable amount of attention due to their efficient application in organocatalysis. To estimate the potential role of the carboxyl group in specific interactions with reaction intermediates, the kinetics of the reactions of 2-(diphenylphosphino)benzoic acid (2-DPPBA) and 4-(diphenylphosphino)benzoic acid (4-DPPBA) with acrylic acid and acrylonitrile was studied in different solvents, and the data were compared with the results obtained previously for the related reactions of triphenylphosphine. The solvent effect on the reaction kinetics was found to be identical to all of the phosphines, suggesting that H bonding with the solvent has no specific influence on the rate for bifunctional tertiary phosphines. Despite of the electron-withdrawing effect of the carboxyl group, the rate of reaction of 2-DPPBA with acrylic acid is 1.4-2.1 times larger than that of triphenylphosphine, implying participation of the neighboring CO2H group of the phosphine in stabilization of the intermediate zwitterion by intramolecular H bonding with the carbonyl oxygen atom of the acrylic acid as a proton acceptor center. The results show that this trend of reactivity was not applicable when acrylonitrile was used as an electrophilic partner since the 2-DPPBA was less reactive than triphenylphosphine. The presence of sp-hybridized atoms of the nitrile group makes intramolecular H bonding with the nitrogen atom of the generated zwitterion strongly disfavored, but leaves the possibility for the H bonding with π electrons of the CN group. Similar effects of anchimeric assistance were not observed for the 4-DPPBA due to disability of the carboxyl group in the para position to participate in any intramolecular H bonding with the reaction intermediates. [ABSTRACT FROM AUTHOR]

ABSTRACT Quaternization of triphenylphosphine with maleic and cis-aconitic acids is strongly accelerated by participation of the cis-carboxyl group in stabilization of the phosphonium zwitterion intermediate by intramolecular hydrogen bonding, in spite of steric hindrance by the acid's reaction center. A similar effect for trans-isomeric acids is not observed, which can be rationalized on the basis of spatial structures of the generated zwitterions, implying an electrostatic interaction between the phosphonium center and carbonyl oxygen atom. The effect of anchimeric assistance decreases when the intramolecular hydrogen bonding disfavors attack of the phosphine on the sterically less hindered carbon atom of the C=C bond, as observed for cis-aconitic acid. [ABSTRACT FROM AUTHOR]

Kinetic data provide evidence that proton transfer to the carbanion centre of a phosphonium zwitterion is the rate-determining step in quarternization reactions of triphenylphosphine with electron-deficient alkenes in solution. This conclusion is based on the third-order , the reactivity of the alkenes, and solvent isotope effects in deuteroacetic acid. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The structures of intermediates and transition states in the reaction of tertiary phosphines with unsaturated carboxylic acids have been calculated at the B3LYP level of theory using the 6-31+G(d,p) basis set. Analysis of the results shows that [1,3]-intramolecular migration of carboxylic proton to carbanionic center of generated zwitterionic intermediate is strongly kinetically unfavorable, and external proton-donor source is essential to complete quaternization. A molecular cluster of the intermediate with one molecule of water has been modeled for intermolecular reaction pathway, but even in this case, the proton transfer remains to be the rate-determining step that is in a good agreement with previous kinetic investigations on this reaction. The data obtained for this reaction have much in common with recent studies on the mechanisms of the Morita-Baylis-Hillman reaction and phosphine-catalyzed [3+2] cycloaddition, which revealed paramount importance of proton-transfer steps. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The optimized reaction conditions allow the regio- and stereoselective synthesis of alkenyl phosphonates. [ABSTRACT FROM AUTHOR]