Rate enhancement by ethylene in the ru-catalyzed ring-closing metathesis of enynes: Evidence for an "ene-then-yne" pathway that diverts through a second catalytic cycle

Angewandte Chemie - International Edition

Volumn 44, Issue 45, 2005, Pages 7442-7447

  Lloyd Jones, Guy C ^a   Margue, Robert G ^a   De Vries, Johannes G ^b  

^a UNIVERSITY OF BRISTOL   (United Kingdom)

^b DSM RESEARCH   (Netherlands)

Author keywords

Carbenes; Isotopic labeling; Metathesis; Reaction mechanisms; Ruthenium

Indexed keywords

ETHYLENE; REACTION KINETICS; RUTHENIUM;

CARBENES; ISOTOPIC LABELING; METATHESIS;

CATALYSIS;

EID: 28044463195     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/anie.200502243     Document Type: Article

References (45)

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38. 2H]-1.
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42. 7,N2))] = 2.8.
43. n]ethylene (94.5% n = 2, 4.9% n = 1, 0.6% n = 0) obtained at the end of co-RCM of 5 and 7 is qualitatively consistent with incomplete equilibration of the gas-solution phases during catalytic turnover.
44. 12C B2/B1 partitioning, which suggests that there may be an additional ethylene accelerating effect, for example, by ethylene acting as a spectator ligand, that increases the rate of pathway A or B1 slightly (for computational analysis of such effects see reference [15c]).
45. 2 when mixed (1/ 1). Since the rate of reaction of 5 with 12, will depend on whether 12 is derived from 7 or 5, this further supports turnover by the primary ene-then-yne (B1) mechanism in the absence of ethylene.