111209-36-0Relevant academic research and scientific papers
New CpFeCO[P(OPh)3](η1-alkenyl) and CpFeCO[P(OPh)3](η1-alkenylacyl) complexes. Crystal and molecular structure of CpFeCO[P(OPh)3](η1-(E)-COC(CH2OMe)=C(Me)Ph) and an NMR method to assign alkenyl ligand structure
Reger, Daniel L.,Klaeren, Stephen A.,Babin, James E.,Adams, Richard D.
, p. 181 - 189 (2008/10/08)
The reaction of [CpFeCO[P(OPh)3](η2-MeC≡CCH 2OMe)]BF4 with three nucleophiles is stereo- and regioselective, yielding CpFeCO[P(OPh)3](η1-(E)-C(CH2OMe)=C(Me)Nuc) (Nuc = Me, Ph, SC6H4Me). These complexes react with CO using [Cp2Fe]BF4 as an oxidative catalyst to yield CpFeCO[P-(OPh)3](η1-(E)-COC(CH 2OMe)=C(Me)Nuc). The alkenylacyl ligand is cleaved with excess oxidant in the presence of alcohol to yield (E)-RO2CC(CH2OMe)=C(Me)Nuc. The reaction of [CpFeCO[P-(OPh)3](η2-MeC≡C-i-Pr)]BF4 with two nucleophiles is selective, yielding CpFeCO[P(OPh)3](η1-(Z)-C-(Me)=C(i-Pr)Me) and CpFeCO[P(OPh)3](η1-(E)-C(Me)=C(i-Pr)SPh), but is not regioselective for Nuc = phenyl, yielding both CpFeCO[P(OPh)3](η1-(E)-C(Me)=C(i-Pr)Ph) and CpFeCO[P(OPh)3](η1-(E)-C-(i-Pr)=C(Me)Ph). For these complexes, oxidatively catalyzed CO insertion reactions go with partial or complete Z-E isomerization of the double bond to yield a mixture of products. Examination of the 13C NMR spectra of previously prepared alkenyl complexes and the new complexes prepared here allow the formulation of two rules based on P-C coupling and chemical shift arguments that assign the structure of the tri- and tetrasubstituted alkenyl ligands in these types of complexes. The solid state structure of CpFeCO[P(OPh)3](η1-(E)-COC(CH2OMe)=C(Me)Ph) was determined by X-ray crystallography and supports these new rules. The molecule crystallizes in space group P1 with a = 13.318 (5) A?, b = 13.400 (3) A?, c = 10.460 (3) A?, α = 104.81 (2)°, β = 103.64 (2)°, γ = 108.10 (2)°, V = 1611 (1) A?3, and Z = 2.
