Syntheses and Reactivities of Stable Halosilylenoids, (Tsi)X₂SiLi (Tsi=C(SiMe₃)₃, X=Br, Cl)

Abstract

Halosilylenoids, stable at room temperature (Tsi)X(2)SiLi (Tsi=C(SiMe(3))(3), X=Br, Cl), were synthesized from the reaction of TsiSiX(3) with lithium naphthalenide. Bromosilylenoid reacted with tBuOH and MeI both at -78 degrees C and at room temperature to give (Tsi)HSiBr(2) and (Tsi)MeSiBr(2), respectively, in high yields; this clearly shows its nucleophilicity. In the reaction of bromosilylenoid with methanol, 2-propanol, and 2,3-dimethyl-1,3-butadiene, the corresponding products, (Tsi)HSi(OMe)(2), (Tsi)HSi(OiPr)Br, and bromo(Tsi)silacyclopent-3-ene, were obtained in high yields; this demonstrates its amphiphilic property, as if bromosilylene would be trapped. Chlorosilylenoid also exhibited both nucleophilic and amphiphilic properties. The (29)Si chemical shifts for (Tsi)Br(2)SiLi, (Tsi)Br(2)SiK, and (Tsi)Cl(2)SiLi were 106, 70, and 87 ppm, respectively.

Stable N‐Heterocyclic Carbene Adducts of Arylchlorosilylenes and Their Germanium Homologues

“…[4c,5] In general, haloorganosilylenes were generated in situ on thermolysis or photolysis of halodisilanes, [6] halotrisilanes, [7] or 7-silanorbonadienes. [8,9] The generated species were either trapped by chemical means or detected by low-temperature matrix-spectroscopic methods. [6][7][8][9] However, all attempts to isolate organosili-A C H T U N G T R E N N U N G con(II) halides that can be manipulated at room temperature have been unsuccessful to date owing to their extremely high reactivity.…”

“…[8,9] The generated species were either trapped by chemical means or detected by low-temperature matrix-spectroscopic methods. [6][7][8][9] However, all attempts to isolate organosili-A C H T U N G T R E N N U N G con(II) halides that can be manipulated at room temperature have been unsuccessful to date owing to their extremely high reactivity. [10] Recent developments in the chemistry of low-coordinate germanium, tin, and lead compounds have shown that the organotetrel(II) halides EXR (E = Ge II , Sn II , Pb II ; X= halogen; R = sterically demanding alkyl or aryl group) have great synthetic potential providing access to tetrel compounds with unusual bonding modes.…”

Theoretical studies on the pentacoordinate silylenoid PhCH2(NH2)CH3SiLiF

“…Most recently, a great breakthrough in the research of silylenoids has been made. Lee et al [15] reported the syntheses of stable halosilylenoids (Tsi)X 2 SiLi (Tsi = C(SiMe 3 ) 3 , X = Br, Cl) at room temperature.…”

Insight into the substitution reactions of silylenoid H2SiLiF with GeH3X (X = F, Cl, Br): a theoretical study

“…Experimental aspects of a few stable silylenoids, Ph 2 Si(O t Bu)Li [32], Tbt(Dip)SiLiBr [33][34][35] (Tbt=2,4,6-tris[bis(trimethylsilyl)-methyl]phenyl; Dip=2,6-diisopropylphenyl), aminonaphthylphenylsilylenoid [30], (Mes) 2 Si(SMes)Li [36], TsiSiX 2 Li [6] (Tsi=C(SiMe) 3 ; X= Br, Cl), and (R 3 Si) 2 SiFLi [10] (R 3 Si=t-Bu 2 MeSi), have been reported. On the other hand, since Clark et al [37] studied the isomers of lithoflurosilylenoid H 2 SiLiF theoretically using ab initio calculations for the first time in 1980, many silylenoids such as R 1 R 2 SiMX (R 1 , R 2 =H, F, OH, NH 2 , Me, Et; M=Li, Na, K, Be, Mg, etc.…”