Base Stabilization of Functionalized Silylene Transition Metal Complexes

The UV‐Light Initiated Reaction of Organosilanes with Tungsten Hexacarbonyl: Formation of an Organosilylene Complex and Organosilylium Salts

“…In analogy to previous work [17,18] we have shown that UV-irradiation of diorganosilanes with transition metal carbonyls gives access to organosilylene complexes, and here especially to the novel heteroleptic diorganosilylene tungsten pentacarbonyl complex [4-t-Bu-2,6-{P(O)(Oi-Pr) 2 } 2 C 6 H 2 ](Ph)SiW(CO) 5 , 2. In addition to this previous work, however, we learned that potentially intramolecularly coordinating substituents in the organosilane precursor control the product distribution and support the formation of organosilylium salts Noteworthy, no formation of related organosilylium salts were reported in course of the synthesis of aminoaryl silanediyl-transition metal complexes [18].…”

“…Notably, the organosilylene complex 2-(Me 2 NCH 2 )C 6 H 4 (H)SiCr(CO) 5 was reported to react with Ph 3 C + BF 4 − to give 2-(Me 2 NCH 2 )C 6 H 4 (F)SiCr(CO) 5 , Ph 3 CH, and BF 3 [17].…”

“…Nevertheless, UV-irradiation of Si-H containing organosilanes with transition metal compounds still is a rather fruitful methodology for the synthesis of both base-free [9][10][11][12][13][14][15][16] and base-stabilized [17][18][19] silylene complexes. Associated with this is the desire to get more insight into the mechanism of Si-H bond activation by transition metal compounds [20][21][22][23][24][25][26][27][28][29] which in turn is relevant even for the topic of C-H bond activation [30] as well as for the understanding of transition metal-catalyzed oligo-and polysilane formation [31].…”

Transition metal compounds containing alkynylsilyl groups − complexes with a metal-silicon bond

“…were employed. Further preparation methods toward alkynylsilyl complexes are: silicon-carbon bond formation in a chromium silyl complex [10], oxidative SiÀH addition of diphenylsilane Ph 2 SiH 2 to an IrÀC^C complex and rearrangement [11], oxidative addition of a SiÀC bond to a platinum complex [12], and rearrangement of an oligosilylalkyne cobalt complex [13].…”

Entrapment of THF‐Stabilized Iridacyclic IrIII Silylenes from Double H−Si Bond Activation and H2 Elimination

“…Investigation of natural atomic charges gave some interesting hints about the driving force of this reaction triggered by THF coordination and outlines the “protean” character of the Ir‐bound hydrido ligand, which is capable of behaving as H − in key hydrosilylation steps or as H + , as shown here. Bonding of THF to the Si center indeed induces a net increase of the formal natural negative charge of the Si‐bound H atoms and a 50 % increase of the natural charge difference Δ q between the H Si1 and H Ir atoms in TS ‐ I ‐ thf compared to TS ‐ I (Δ q (H Ir −H Si ) TS‐I‐ thf =0.26, Δ q (H Ir −H Si ) TS‐I =0.17; Figure b). The formation of H 2 is essentially assisted by coulombic interactions between H Si1 and H Ir .…”