22808-06-6Relevant academic research and scientific papers
Synthesis of Molybdenum(VI) Neopentylidene Neopentylidyne Complexes
Tafazolian, Hosein,Schrock, Richard R.,Müller, Peter
supporting information, p. 2888 - 2891 (2019/08/30)
Mo(C-t-Bu)(CH-t-Bu)(Cl)(PMe2Ph)2 (1) was prepared as off-white crystals in 26% yield through addition of 2.5 equiv of Mg(CH2-t-Bu)2 to Mo(O)[OC(CF3)3]4 in diethyl ether followed by 3 equiv of PMe2Ph and a workup that includes dichloromethane (the source of Cl). Compound 1 is largely a syn isomer initially that equilibrates to give approximately a 1:1 mixture of syn and anti isomers within 1-2 h. Compound 1 reacts with Li(3,5-dimethylpyrrolide) to give Mo(C-t-Bu)(CH-t-Bu)(η1-Me2Pyr)(PMe2Ph)2 (2a) as a pale yellow solid in 76% yield, and 2a reacts with Ph3SiOH to give a mixture of syn and anti Mo(C-t-Bu)(CH-t-Bu)(OSiPh3)(PMe2Ph)2 (3a) in 84% yield. All three compounds tend to lose PMe2Ph to give 14e monophosphine complexes with the formulas Mo(C-t-Bu)(CH-t-Bu)(X)(PMe2Ph) (X = Cl, Me2Pyr, or OSiPh3), none of which could be isolated. X-ray studies show the structures of 1, 2a, and 3a to be analogous with τ values of 0.45, 0.53, and 0.69, respectively.
Formation of an alkyne during degradation of metal-alkylidyne complexes
Levy, Ophir,Musa, Sanaa,Bino, Avi
, p. 12248 - 12251 (2013/09/02)
The compound [(Ot-Bu)3WCt-Bu] (1) (t-Bu = C(CH3) 3) decomposes upon contact with water and several organic products are formed, including di-tert-butylacetylene, t-BuCCt-Bu. This process is reminiscent of the degradation of trinuclear metal-alkylidyne complexes in which free carbynes are ejected into solution, couple and form alkynes along with many other products. The reactivity pattern of the resulting t-BuC carbynes that includes extensive hydrogen abstraction, cleavage of alkynes and lack of reactivity towards alkenes is indicative of a quartet (S = 3/2) spin state. A similar spin state was assigned to other RC (R = alkyl) species that were produced by degrading M3-alkylidyne (M = transition metal) complexes in water. t-BuCCt-Bu is also produced during thermal decomposition of solid 1. In 1977 Fischer and co-workers reported a very similar process in which solids of Br(CO)4CrCR1 and Br(CO)4CrCR2 were co-thermolyzed to produce R1CCR2, R 1CCR1, and R2CCR2. Fischer had considered the involvement of free carbynes in the making of the alkynes but later resorted to other explanations. The current results suggest that his original proposal is indeed valid.
Oxidative addition of carbon-oxygen and carbon-nitrogen double bonds to WCl2(PMePh2)4. Synthesis of tungsten metallaoxirane and tungsten oxo- and imido-alkylidene complexes
Bryan, Jeffrey C.,Mayer, James M.
, p. 2298 - 2308 (2007/10/02)
WCl2L4 (1, L = PMePh2) reacts rapidly with a variety of ketones and aldehydes to form bis(η2-ketone) or bis(η2-aldehyde) complexes WCl2(η2-O=CRR′)2L2 (2, 3)
