Silicon–Carbon and Silicon–Nitrogen Multiply Bonded Compounds

Ab initio Study of Some Intramolecularly Donor‐Stabilized Silenes

“…[5] This supports the idea that the interaction of silenes with donor groups leads to an elongation of the Si=C bond [3][4][5][6] caused by a weakening of the Si-C π interaction. The Si=C distances of the kinetically stabilized silenes (Me 3 Si) 2 Si=C-(OSiMe 3 )Ad (1.764 Å, Ad = 1-adamantyl) [13] and (Me 3 Si)-(tBuMe 2 Si)=AdЈ (1.741 Å, AdЈ = 2-adamantylidene) [14] are almost the same as those of the thermodynamically stabilized silenes, but these elongations were accounted for by the electronic effects of the substituents. [14,15] For compound 3 the situation is quite comparable to compound 1, as the results in Table 2 show.…”

“…The rotational barriers determined by this quantum mechanical approach agree surprisingly well with the spectroscopically determined rotational barriers, supporting our interpretation of the experimental data. 2 , where values of 50 kJ/mol and 65 kJ/ mol, respectively, were reported. [25] The calculated rotational barriers of isomer interconversion are smaller than in uncomplexed silenes, which were found to be about 160 kJ/mol.…”

“…Some highly congested silenes could be isolated and structurally characterized. [1,2] Coordination of donor molecules like amines, THF or fluoride anions to the electrophilic silene silicon atom leads to an effective thermodynamic stabilization of the compounds. [3][4][5][6] A particularly effective stabilization is expected, when substituents with donor groups are introduced to the silenes and intramolecular donor-acceptor interaction between this donor group and the electrophilic silicon center is possible.…”

Hosomi–Sakurai reactions of silacyclohexenes

“…Originally considered to be objects of solely theoretical interest, silenes, compounds containing a silicon carbon double bond, have been demonstrated to be accessible species. [1][2][3] Although a number of silenes are isolable, Fig. 1, 4-11 most are highly reactive transient species that exhibit a unique reactivity profile, Fig.…”

Synthesis and Structure of a 2,4‐Unsubstituted cis/trans‐1,3‐Disilacyclobutane by Dehydrofluorination of a Highly Hindered Fluorosilane

“…[3] Alternatively, α-lithiohalosilanes have also been prepared by conjugate addition of organolithium reagents to halovinylsilanes. Since the first reaction of this type, described by Jones and Lim in 1977, [4,5] many other transient silenes have been synthesized by this route, particularly by Auner and coworkers, [6] but also by some other authors. [7] Despite the use of more and more bulky substituents, all these silenes are unstable at room temperature and lead to dimeric 1,3-disilacyclobutanes (head-to-tail dimerization), except for the stable dimesitylneopentylsilene.…”