TY - JOUR
T1 - Reactions of co-ordinated ligands. Part 15. The cycloaddition of electronegatively substituted unsaturated systems to tricarbonyl(η-N-methoxycarbonyl-1H-azepine)-iron and -ruthenium and tricarbonyl(η-cyclohepta-2,4,6-trien-1-one)iron
AU - Green, Michael
AU - Heathcock, Susan M.
AU - Turney, Terence W.
AU - Mingos, D. Michael P.
PY - 1977/12/1
Y1 - 1977/12/1
N2 - Hexafluoroacetone, tetracyanoethylene, and 1,1 dicyano-2,2-bis(trifluoromethyl)ethyiene form exo-1,3 adducts with tricarbonyl(η-cyclohepta-2,4,6-trien-1-one)iron and tricarbonyl(η-N-methoxycarbonyl-1H-azepine)-iron and -ruthenium. A 1,6 adduct is also obtained with the azepineiron system. Deuteriation experiments show that the unco-ordinated double bond is the initial site of electrophilic attack. The 1,3-tetracyanoethylene adduct of the cycloheptatrienoneiron complex readily isomerises to a 1,5 adduct in solution. The generally accepted dipolar mechanism for these cycloaddition reactions is critically assessed and an alternative concerted reaction path is presented.
AB - Hexafluoroacetone, tetracyanoethylene, and 1,1 dicyano-2,2-bis(trifluoromethyl)ethyiene form exo-1,3 adducts with tricarbonyl(η-cyclohepta-2,4,6-trien-1-one)iron and tricarbonyl(η-N-methoxycarbonyl-1H-azepine)-iron and -ruthenium. A 1,6 adduct is also obtained with the azepineiron system. Deuteriation experiments show that the unco-ordinated double bond is the initial site of electrophilic attack. The 1,3-tetracyanoethylene adduct of the cycloheptatrienoneiron complex readily isomerises to a 1,5 adduct in solution. The generally accepted dipolar mechanism for these cycloaddition reactions is critically assessed and an alternative concerted reaction path is presented.
UR - http://www.scopus.com/inward/record.url?scp=37049101267&partnerID=8YFLogxK
U2 - 10.1039/DT9770000204
DO - 10.1039/DT9770000204
M3 - Article
AN - SCOPUS:37049101267
SP - 204
EP - 211
JO - Dalton Transactions
JF - Dalton Transactions
SN - 1477-9226
IS - 2
ER -