C-C bond insertion of a complexed phosphinidene into 1,6-methano[10]annulene.
Reaction of electrophilic phosphinidene complex [MePW(CO)5] with 1,6-methano-[10]annulene results in the sole formation of the isomeric C-C insertion products 6 c (main) and 6 d (minor). The single-crystal X-ray structure of the complexed 1,7-methano-3-phospha[11]annulene (6 c) shows a syn-W(CO)5 group at the exo bent phosphorus. The structure displays C-C bond alternation without bonding between the bridgehead carbon atoms. Density functional theory calculations indicate 6 c to result from a concerted disrotatory ring opening of an undetected tricyclic exo-syn phosphirane intermediate. The endo-anti phosphirane cannot undergo ring expansion, due to the high barrier that is associated with an intramolecular antara-antara retro Diels-Alder reaction. The stabilizing effect of transition-metal coordination is discussed.
Bulo
Rosa E
RE
Vrije Universiteit, FEW, Department of Chemistry, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
Trion
Linda
L
Ehlers
Andreas W
AW
de Kanter
Fransiscus J J
FJ
Schakel
Marius
M
Lutz
Martin
M
Spek
Anthony L
AL
Lammertsma
Koop
K