6 research outputs found

    Synthesis of trans-mono(silyl)palladium(II) bromide complexes

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    The stoichiometric reaction of cis-[Pd(ITMe)2(SiR3)2], where (SiR3 = SiMe3 and SiMe2Ph and ITMe = 1,3,4,5-tetramethylimidazol-2-ylidene) with allyl bromide affords the corresponding allylsilanes along with complexes of the type trans-[Pd(ITMe)2(SiR3)(Br)]. The structure of trans-[Pd(ITMe)2(SiMe2Ph)Br] 2b has been determined in the solid state and displays a slightly distorted square-planar geometry with the two N-heterocyclic carbene ligands in a trans-configuration

    Comparison of the reactivity of the low buried-volume carbene complexes (ITMe)2Pd(PhC≡CPh) and (ITMe)2Pd(PhN=NPh)

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    The novel Pd(0)-azobenzene complex (ITMe)2Pd(PhN=NPh) (5) (ITMe = 1,3,4,5-tetramethylimidazol 2-ylidene) has been isolated and characterized in the solid state and by cyclic voltammetry. Its reactivity towards E-E’ bonds (E, E’= Si, B, Ge) has been compared with that of the known palladium carbene complex (ITMe)2Pd(PhC≡CPh) (2). Whereas 2 reacts with all E-E’ bonds studied, 5 only reacted with B-B and B-Si moieties, echoing our previous catalytic studies on azobenzenes

    Transition metal catalyzed element–element′ additions to alkynes

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    The efficient and stereoselective synthesis of, or precursors to, multi-substituted alkenes has attracted substantial interest due to their existence in various industrially and biologically important compounds. One of the most atom economical routes to such alkenes is the transition metal catalyzed hetero element–element′ π-insertion into alkynes. This article provides a thorough up-to-date review on this area of chemistry, including discussions on the mechanism, range of Esingle bondE′ bonds accessible and the stoichiometric/catalytic transition metal mediators employed

    (N-Heterocyclic Carbene)<sub>2</sub>‑Pd(0)-Catalyzed Silaboration of Internal and Terminal Alkynes: Scope and Mechanistic Studies

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    Pd­(ITMe)<sub>2</sub>(PhCCPh) acts as a highly reactive precatalyst in the silaboration of terminal and internal alkynes to yield a number of known and novel 1-silyl-2-boryl alkenes. Unprecedented mild reaction temperatures for terminal alkynes, short reaction times, and low catalytic loadings are reported. During mechanistic studies, <i>cis</i>-Pd­(ITMe)<sub>2</sub>(SiMe<sub>2</sub>Ph)­(Bpin) was directly synthesized by oxidative addition of PhMe<sub>2</sub>SiBpin to Pd­(ITMe)<sub>2</sub>(PhCCPh). This represents a very rare example of a (silyl)­(boryl)palladium complex. A plausible catalyst decomposition route was also examined

    Comparison of the Reactivity of the Low Buried-Volume Carbene Complexes (ITMe)<sub>2</sub>Pd(PhCî—¼CPh) and (ITMe)<sub>2</sub>Pd(PhNî—»NPh)

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    The novel Pd(0)-azobenzene complex (ITMe)<sub>2</sub>Pd­(PhNNPh) (<b>5</b>) (ITMe = 1,3,4,5-tetramethylimidazol-2-ylidene) has been isolated and characterized in the solid state and by cyclic voltammetry. Its reactivity toward E–E′ bonds (E, E′ = Si, B, Ge) has been compared with that of the known carbene complex (ITMe)<sub>2</sub>Pd­(PhCCPh) (<b>2</b>). Whereas <b>2</b> reacts with all E–E′ bonds studied, <b>5</b> only reacted with B–B and B–Si moieties, echoing our previous catalytic studies on azobenzenes
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