Facile Bond Activation of Small Molecules by an Acyclic Imino(silyl)silylene

Abstract

The activation of small molecules by silylenes bearing unique electronic properties has been well established in the past few decades. Here, we disclose the reactivity study of acyclic imino(silyl)silylene 1 with an N‐heterocyclic imine ligand (NHI) towards various small molecules. Silylene 1 undergoes facile activation of gaseous molecules like dihydrogen, ethylene, and carbon dioxide. While the cycloaddition of carbonyl compounds to 1 was shown as a straightforward synthetic approach of oxasilacycles, reaction with silane as well as borane led to the corresponding E−H (E=Si, B) insertion products. Moreover, reaction with heavier chalcogens allow the isolation of neutral three‐coordinate silicon‐heavier chalcogen double bond complexes.

A Bis(silylene)silole – synthesis, properties and reactivity

“…24,[30][31][32] These 29 Si NMR signals are in the typical region of tetracoordinated amidinate stabilized silicon chalcogenides bracketed by the values for the corresponding hypersilyl-and bissilylaminosubstituted chalcogenides 13 and 14 (see Figure 5). 24,33 Compared to trico-ordinated silicon chalcogenides (heavy silaketones) such as 10-12, the 29 Si resonances of 7-9 are significantly shifted to lower frequencies [34][35][36][37][38][39] but they are clearly distinguished from those of the pentacoordinated silicon chalcogenides 16 (Figure 5). 31 Based on this assessment of the 29 Si NMR chemical shifts, we place the electronic effects of the silole ring in chalcogenides 7-9 between the electron donating hypersilyl group (in 13) and the electronegative aminosubstituent (in 14) or the even more electronegative phenoxysubstituent in the bis(siliconchalcogenide) 15.…”

Dearomatization of C6 Aromatic Hydrocarbons by Main Group Complexes

“…[25] In the reaction of acyclic imino(silyl)silylene 24 with xanthone at ambient temperature, similar [1 + 4] cyclo-addition product 25 was obtained (Scheme 3c). [26] Compound 25 is stable even when heated to 100 °C and rearomatized reaction was not observed. In addition, the first example of insertion of metal-substituted silylene fragment into an aromatic ring of naphthalene and further ring opening and rearrangement were investigated by Lee, [27] Chen, Peng and coworkers (Scheme 3d).…”

“…In addition, the first example of insertion of metal-substituted silylene fragment into an aromatic ring of naphthalene and further ring opening and rearrangement were investigated by Lee, [27] Chen, Peng and coworkers (Scheme 3d). [28] Treatment of a trichlorosilane Cl 3 SiC-(SiMe 3 ) 3 (26) with 3.8 equivalents of lithium naphthalenide at À 35 °C afforded a [1 + 2] cycloaddition product 27, which was first generated by bromodilithiosilane and naphthalene at 110 °C by the Lee group in 2008. [27] Treatment of 27 with an equivalent of KO t Bu at room temperature provided the silacyclopropanyl potassium 28 via transmetallation.…”

Strain‐Driven, Non‐Catalysed Ring Expansion of Silicon Heterocycles

“…[13,14] The same effect could also be utilised in the photolysis of dimesitylalkinylsilanes, as under photolytic conditions dimesitylsilylene would be liberated and react with the remaining alkyne. [15] [2 + 1] cycloaddition reactions of transient silylenes were studied with many silylenes, such as dimesitylsilylene Mes 2 Si by Sekiguchi and Conlin, [16,17] Tokitoh's TbtSiMes (Tbt = 2,4,6tris[bis(trimethylsilyl)methyl]phenyl), [18] bis(diisopropylamino)silylene, [19] t Bu 2 Si [20,21] and, more recently, NHI-substituted (NHI = N-heterocyclic imine), [22] silylsubstituted [23,24] or allylaminosilylenes. [7] The [2 + 1] cycloaddition was also studied with stable silylenes, for instance with Power's acyclic (TerS) 2 Si (Ter = terphenyl) [25] or Kira's dialkylsilylene.…”