169780-73-8Relevant academic research and scientific papers
Migratory insertion of a phosphorus ligand into a transition metal-alkyl bond
Nakazawa, Hiroshi,Yamaguchi, Yoshitaka,Mizuta, Tsutomu,Ichimura, Satoshi,Miyoshi, Katsuhiko
, p. 4635 - 4643 (1995)
Treatment of Cp(CO)(R1)Fe{PN(Me)CH2CH2NMe(OR2)} (R1 = R2 = Me, 1a; R1 = Me, R2 = Et, 2a; R1 = CH2Ph; R2 = Me, 3a) with BF3·OEt2 and then with PPh3 yields [Cp(CO)(PPh3)Fe(PN(Me)CH2CH2NMe(R 1)}]+ (R1 = Me, 1b; R1 = CH2Ph, 3b). The reaction proceeds via the formation of a cationic phosphenium complex, [Cp(CO)(R1)Fe{PN(Me)CH2CH2NMe}]+, by the abstraction of an OR group as an anion from a phosphorus atom, and then migratory insertion of the phosphenium ligand into the iron-alkyl bond takes place to give [Cp(CO)(BF2OR2)Fe{PN(Me)CH2CH 2NMe(R1)}]+, which is characterized by spectroscopic data. The cationic complex readily reacts with PPh3 to give the final product. A η5-C5Me5 derivative of 1a and a monoamino-substituted phosphite complex Cp(CO)(Me)Fe{PN(Me)CH2CH2O(OMe)} show the same reactivity. The reaction of silyl complexes Cp(CO)(SiMe3)Fe{PN(Me)CH2CH2NMe(OR)} (R = Me, Et) with BE3·OEt2 affords a phosphenium complex [Cp(CO)(SiMe3)Fe{PN(Me)CH2CH2NMe}]+, which does not show the migratory insertion into an iron-silyl bond. Iron complexes Cp(CO)(CH2OMe)Fe{PN(Me)CH2CH2NMe(OR)} (R = Me, 9a; R = Et, 10a) having an alkoxy group both on a carbon and on a phosphorus react with BF3·OEt2 and then with PPh3 to give [Cp(CO)(CH2PPh3)Fe{PN(Me)CH2CH2NMe(OR)}]+ (R = Me, 9e; R = Et, 10e). The results prove that the OMe in the CH2OMe ligand is selectively abstracted to give the methylidene complex which is trapped with PPh3 to give a phosphine ylide complex. Complexes 1b·BF4 and 10e·BF4 have been characterized by X-ray diffraction (crystal data for 1b·BF4, monoclinic, P21/n, a = 9.099(1) A?, b = 13.727 (2) A?, c = 23.134 (5) A?, β = 91.48 (1)°, Z = 4, R = 0.063; for 10e·BF4, orthorhombic, Pcab, a = 18.033 (6) A?, b = 24.619 (6) A?, c = 14.501 (4) A?, Z = 8, R = 0.059).
