Nine substituted sulfonyl-stabilized phosphorus ylides were prepared by treating their intermediate ylide analogues with phenylmethanesulfonyl fluoride. The stoichiometric ratio of the reactants for each preparation needed to be adjusted according to the basicity of each ylide intermediate. The nine ylide compounds were then subjected to conventional (sealed-tube) gas-phase pyrolysis at 470545 K. The pyrolytic reactions were homogeneous and obeyed a first-order rate equation. The values of the Arrhenius log A (s1) and Ea (kJ mol1) obtained for these reactions averaged 11.12 ± 2.00 and 131.8 ± 24.4, respectively. Analysis of the pyrolysates from conventional pyrolysis and from flash vacuum pyrolysis at 600 K showed the products to be complex mixtures of triphenylphosphine, triphenylphosphine oxide, triphenylphosphine sulfide, and symmetric and unsymmetric alkenes. Conventional pyrolysis also gave novel mixed sulfones and, for the p-methoxyaryl substituent, p-anisaldehyde. The products of the reactions under study are explained on the basis of a mechanism involving a sulfonyl carbene intermediate, and the reaction mechanism is used to rationalize the kinetic results and molecular reactivities.Key words: ylides, synthesis, pyrolysis, kinetics, mechanism.
通过处理它们的中间偶氮化物类似物与苯甲磺酰氟,制备了九种替代磺酰稳定的磷叶类化合物。每种制备所需的反应物的化学计量比需要根据每种叶类中间体的碱性进行调整。然后,这九种叶类化合物经受传统(密封管)气相热解反应,在470-545 K条件下进行。热解反应是均相的,并遵守一级速率方程。对于这些反应获得的阿伦尼乌斯对数A(s-1)和Ea(kJ mol-1)的值分别平均为11.12 ± 2.00和131.8 ± 24.4。从传统热解和600 K的快速真空热解得到的热解产物分析显示,产物是三苯基膦、三苯基膦氧化物、三苯基膦硫化物、对称和非对称烯烃的复杂混合物。传统热解还产生了新型混合磺酮,对于p-甲氧基芳基取代基,产生了对甲醛。根据涉及磺酰卡宾中间体的机制解释了研究中的反应产物,并利用反应机制来解释动力学结果和分子反应性。关键词:叶类化合物,合成,热解,动力学,机制。