The mechanism of thermal elimination of urea and thiourea derivatives. Part 1. Rate data for pyrolysis of N-acetylurea,N-acetylthiourea,N,N -diacetylthiourea,and N-acetylthiobenzamide

Rates of thermal decomposition of N-acetylurea (1), N-acetylthiourea (2), N,N′-diacetylthiourea (3), and N-acetylthiobenzamide (4) have been measured over a 45 K range for each compound. The molecules were found to undergo unimolecular first-order elimination reactions for which log A = 11.9, 11.6, 11.8, and 13.4 s^-1, and E_a = 181.2, 135.9, 128.3, and 130.3 kJ mol^-1, respectively. The reactivities of these compounds have been compared with those of amide derivatives and with each other. Product analysis together with the kinetic data were used to outline feasible pathways for the elimination reactions of the compounds under study. © 1996 John Wiley & Sons, Inc.     

(η3-allyl)palladium(II) catalysts for the addition polymerization of norbornene derivatives with functional groups

Cycloaliphatic polyolefins with functional groups were prepared by the Pd(II)-catalyzed addition polymerization of norbornene derivatives. Homo- and copolymers containing repeating units based on bicyclo[2.2.1] hept-5-en-2-ylmethyl decanoate (endo/exo-ratio = 80/20), bicyclo[2.2.1]hept-5-ene-2-carboxylic acid methyl ester (exo/endo = 80/20), bicyclo[2.2.1]hept-5-ene-2-methanol (endo/exo = 80/20), and bicyclo[2.2.1]hept-5-ene-2-carboxylic acid (100% endo) were prepared in 49–99% yields with {(η³-allyl)Pd(BF₄)} and {(η³-allyl)Pd(SbF₆)} as catalysts. The catalyst containing the hexafluoroantimonate ion was slightly more active than the tetrafluoroborate based Pd-complex.