Fused tricyclic phosphiranes--analysis of phosphorus chemical shieldings.
1,2-Addition of transient W(CO)(5)-complexed phosphinidenes exo to hexamethyl Dewar benzene affords the novel 3-phosphatricyclo[3.2.0.0(2,4)]hept-6-ene complexes. The fused tricyclic phosphiranes are obtained as both the Z and the thermally less stable E isomers, the (31)P NMR chemical shifts of which differ by about 60 ppm. A computational investigation shows that the phosphorus pyramidalization and the presence of the gamma double bond are responsible for this effect. The semiquantitative results contribute to a more systematic understanding of the structural influences on (31)P chemical shieldings. The congested double bond of the Z isomer can be epoxidized with m-chloroperbenzoic acid (MCPBA) to afford a fused tetracyclic P,O bis-adduct.
Couzijn
Erik P A
EP
Department of Organic Chemistry, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1083, Amsterdam, The Netherlands.
Ehlers
Andreas W
AW
Slootweg
J Chris
JC
Schakel
Marius
M
Krill
Steffen
S
Lutz
Martin
M
Spek
Anthony L
AL
Lammertsma
Koop
K
D000465:Algorithms; D002723:Chlorobenzoates / Q000737:chemistry; D004852:Epoxy Compounds / Q000737:chemistry; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D007536:Isomerism; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry*
D002723:Chlorobenzoates; D004852:Epoxy Compounds; D006575:Heterocyclic Compounds, 3-Ring; D008024:Ligands; D009943:Organophosphorus Compounds; D010758:Phosphorus; C000433:3-chloroperbenzoic acid