TY - JOUR
T1 - Reactions of molybdenum and tungsten η2-C,C-vinyl complexes [Mη3-C(CF3)C(CF3)SR(CF3CCCF3)(η5-C5H5)] with alkynes leading to novel metallacycles
AU - Carlton, L.
AU - Agh-Atabay, Naz M.
AU - Davidson, Jack L.
PY - 1991/8/7
Y1 - 1991/8/7
N2 - The reactions of [M?3-C(CF3)C(CF3)SR(CF3C=CCF3)(?5-C5H5)](M = Mo, R = iPr; M = W, R = Me, iPr, tBu) with alkynes R'C=CR?, (R' = R? = Me, Et, Ph; R' = Ph, R? = Me) gives isomeric ?2-vinyl [M?3-C(CF3)C(CF3)C(R?)=C(R')(SR)(CF3C=CCF3)(?5-C5H5)] and/or ?4-butadienyl complexes [M?4-C(CF3)C(CF3)=C(R?)C(R')(SR)(CF3C=CCF3)(?5-C5H5)] (not all cases) apparently as a result of insertion of the incoming alkyne into the CS bond of the ?3-C(CF3)C(CF3)SR ligand. Thermolysis of [W?3-C(CF3)C(CF3)C(Me)=C(Ph)SiPr(CF3C=CCF3)(?5-C5H5)] in hexane at 55°C gives [WSiPr?5-C(CF3)C(CF3)C(CF3)C(CF3)C(Me)C(Ph)(?5-C5H5)]. In contrast thermolysis of [Mo?3-C(CF3)C(CF3)C(Me)=C(Me)SiPr(CF3C=CCF3)(?5-C5H5)] in hexane at 70°C gives [Mo?4-C(Me)C(Me)=C(CF3)C(CF3)(H)(CF3C=CCF3)(?5-C5H5)] via the intermediate [Mo?4-C(CF3)C(CF3)=C(Me)C(Me)SiPr(CF3C=CCF3)(?5-C5H5)]. Fluxional behaviour in complexes [M?3-C(CF3)C(CF3)C(R?)=C(R')(SR)(CF3C=CCF3)(?5-C5H5)] has been studied by variable temperature 19F NMR spectroscopy and two processes detected. The first involves rapid exchange between two isomeric forms and is ascribed to inversion at either the sulphur or the ß-carbon of the C(CF3)C(CF3)C(R?)=C(R')SR ligand. The second appears to involve restricted rotation of the CF3 attached to the ß-carbon. © 1991.
AB - The reactions of [M?3-C(CF3)C(CF3)SR(CF3C=CCF3)(?5-C5H5)](M = Mo, R = iPr; M = W, R = Me, iPr, tBu) with alkynes R'C=CR?, (R' = R? = Me, Et, Ph; R' = Ph, R? = Me) gives isomeric ?2-vinyl [M?3-C(CF3)C(CF3)C(R?)=C(R')(SR)(CF3C=CCF3)(?5-C5H5)] and/or ?4-butadienyl complexes [M?4-C(CF3)C(CF3)=C(R?)C(R')(SR)(CF3C=CCF3)(?5-C5H5)] (not all cases) apparently as a result of insertion of the incoming alkyne into the CS bond of the ?3-C(CF3)C(CF3)SR ligand. Thermolysis of [W?3-C(CF3)C(CF3)C(Me)=C(Ph)SiPr(CF3C=CCF3)(?5-C5H5)] in hexane at 55°C gives [WSiPr?5-C(CF3)C(CF3)C(CF3)C(CF3)C(Me)C(Ph)(?5-C5H5)]. In contrast thermolysis of [Mo?3-C(CF3)C(CF3)C(Me)=C(Me)SiPr(CF3C=CCF3)(?5-C5H5)] in hexane at 70°C gives [Mo?4-C(Me)C(Me)=C(CF3)C(CF3)(H)(CF3C=CCF3)(?5-C5H5)] via the intermediate [Mo?4-C(CF3)C(CF3)=C(Me)C(Me)SiPr(CF3C=CCF3)(?5-C5H5)]. Fluxional behaviour in complexes [M?3-C(CF3)C(CF3)C(R?)=C(R')(SR)(CF3C=CCF3)(?5-C5H5)] has been studied by variable temperature 19F NMR spectroscopy and two processes detected. The first involves rapid exchange between two isomeric forms and is ascribed to inversion at either the sulphur or the ß-carbon of the C(CF3)C(CF3)C(R?)=C(R')SR ligand. The second appears to involve restricted rotation of the CF3 attached to the ß-carbon. © 1991.
UR - http://www.scopus.com/inward/record.url?scp=0011591052&partnerID=8YFLogxK
M3 - Article
SN - 0022-328X
VL - 413
SP - 205
EP - 221
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
IS - 1-3
ER -