257883-63-9Relevant academic research and scientific papers
Synthesis, structure, and reactivity of titanium phosphinimide thiolate complexes
Ong, Chris,Kickham, James,Clemens, Steve,Guérin, Fred,Stephan, Douglas W.
, p. 1646 - 1653 (2008/10/08)
A series of titanium-phosphinimide thiolate complexes were prepared employing either thiolate for chloride metathesis or protonolysis of metal-carbon bonds by thiols. In these ways the following species were obtained: CpTi(NPR′s)(SR)2 (R′ = i-Pr, R = CH2Ph 3; Ph 4, t-Bu 5, (SR)2 = S2(CH2)2 6, S2(CH2)3 7, S2(CH2)2C6H4 8; R′ = t-Bu, R = CH2Ph 9; Ph 10, t-Bu 11); Cp(t-Bu3PN)TiMe(SPh) 12; and (t-Bu3PN)2Ti(SR)2 (R = CH2Ph 14; Ph 15, t-Bu 16). Reactions of (t-Bu3PN)2TiMe2 with 1 equiv of HSCH2Ph gave a cyclometalated species 17, (t-Bu3PN)2Ti(η2-SCHPh). The analogous reaction of 1 equiv of phenylthiol generated the species (t-Bu3PN)2Ti(Me)(SPh) 18. While 17 and 18 could not be isolated free of 14 and 15, respectively, the analogous reaction of tert-butylthiol afforded (t-Bu3PN)2Ti(Me)(St-Bu) 19 cleanly. Attempts to effect sulfur insertion into Ti-Me bonds were undertaken via the reaction of (t-Bu3PN)2TiMe2 with S8 but gave instead the species (t-Bu3PN)2Ti(η2-S5) 20. The reactivity of the thiolate derivatives, 3-5 with excess AlMe3, was examined. Spectroscopic and crystallographic studies revealed the formation of (CpTi(μ-SR)(μ-NPi-Pr3)(C)(AlMe2)2-(μ-S R)AlMe (R = CH2Ph 21, Ph 22, t-Bu 23). Analogous reactions of 7 and 8 with AlMe3 afforded [Cp(i-Pr3PN)Ti(SRS)].(AlMe3)3 (R = (CH2)3 24, ((CH2)2(C6H4)) 25). The mechanistic implications of the observed multiple C-H bond activation are considered. Crystallographic studies of 4, 6, 7, 14, 16, and 20-23 are reported.
Titanium-thiolate-aluminum-carbide complexes by multiple C-H bond activation
Guerin, Frederic,Stephan, Douglas W.
, p. 3698 - 3701 (2007/10/03)
All three C-H bonds of a methyl group are activated in the reaction of [Cp(iPr3PN)Ti(SR)2] with AlMe3 [Eq. (1)]. The Ti-Al-carbide clusters formed contain a severely distorted tetrahedral carbide carbon atom with a relatively short bond to Ti, which is attributed to a relative increase in the Lewis acidity of the Ti center as a result of the interaction of the S and N donors with Al.
