413621-29-1

Upstream product

• 412347-21-8 Pt(η(2)-(CH3)3SiCCC6H5)(((CH3)2CH)2PCH2CH2N(CH3)2) 
• 412347-28-5 (Pt((CH₃)3Si)(CCC₆H₅)(((CH₃)2CH)2PCH₂CH₂N(CH₃)2))2Pt 
• 12130-66-4 bis(cycloocta-1,5-diene)platinum⁽⁰⁾ 
• 132280-91-2 1-(diisopropylphosphino)-2-(dimethylamino)ethane 
• 2170-06-1 1-Phenyl-2-(trimethylsilyl)acetylene 

Relevant academic research and scientific papers

Experimental and theoretical studies on the platinum-mediated selective C(sp)-Si bond cleavage of alkynylsilanes

A series of cis-alkynyl(silyl)platinum(II) complexes was prepared via the chemoselective C(sp)-Si bond cleavage of alkynylsilanes by a platinum(0) complex ligated with the P-N hemilabile bidentate ligand. The coordination of the triple bond to the platinum center triggers selective C(sp)-Si bond cleavage. Hammett plots of the 31P{1H} NMR spectroscopic properties (δ and J values) reflect an electronic effect on platinum(II) complexes; trans substituents of arylethynyl groups are influenced, but cis-positioned silyl groups are not affected, as evidenced by 29Si{1H} NMR. In comparison, Hammett plots show that C(sp)-Si bond cleavage rates are accelerated by electron-rich alkynylsilanes, which is opposite to the ordinary oxidative addition of aryl halides to transition metals often observed in catalytic cross-coupling reactions. A DFT calculation reveals that intermediates and transition states are stabilized by electron-rich alkynylsilanes and that the five-membered hemilabile P-N ligand is essential, in which a reactive electron-deficient 14-electron platinum(0) species is produced via the dissociation of nitrogen, giving rise to a monodentate phosphine coordination. Electron-rich alkynylsilanes allow decreased π back-donation from the platinum center to the ligand, accelerating the dissociation of the more labile nitrogen. Steric congestion between diisopropylphosphino and silyl groups thermodynamically disfavors C(sp)-Si bond cleavage.

Thermal and photochemical silicon-carbon bond activation in donor-stabilized platinum(0)-alkyne complexes

Reaction of Pt(COD)2 with Me3SiC≡CPh and a bidentate chelating ligand leads to the formation of the corresponding donor-stabilized Pt-η2-alkyne complexes (PN)Pt(η2-Me3SiC≡CPh) (1) and (dcpe)Pt(η2-Me3SiC≡CPh) (3) (PN = (diisopropylphosphinodimethylamino)-ethane; dope = bis(dicyclohexylphosphino)ethane). The nitrogen donor ligand in 1 facilitates the cleavage of the Si-C(sp) bond, and the Pt(II) complex (PN)Pt(SiMe3)(C≡CPh) (2) is formed at room temperature. In contrast, the bisphosphino-substituted compound 3 has been isolated as a thermally robust Pt(0) complex. However, the silicon-carbon bond in the latter compound can be photochemically activated, and the oxidative addition product (dcpe)Pt-(SiMe3)(C≡CPh) (4) is generated. Both Si-C(sp) bonds in Me3Si-C≡C-C≡C-SiMe3 have been thermally activated by a (PN)Pt fragment to afford the dinuclear Pt(II) species (PN)-Pt(SiMe3)-C≡C-C≡C-Pt(SiMe3)(PN) (6).