Note on the Preparation of Alkyl‐ and Oxaälkyl‐dimethylsilanols

Abstract

Summary. The preparation of a series of alkyl-and (mono-, di-and poly-) oxaalkyl-dimethylsilanols is described. The stability of these compounds on storage is considerably increased by previous filtration through a silica gel column.For a study of the reaction of silanols with surface hydroxyl groups of (hydrated) amorphous silicon dioxide, we prepared a series of R-dimethyl-silanols with the following R-substituents:P8 m = 3 P G n = 4 P g m = 4 P 7 n = 5 Of these, trimethylsilanol [l], ethyl-dimethylsilanol [Z] and propyl-dimethylsilanol [3] have been described (see also [4] [S]).The substituents R, to be introduced, were either 1-Bromo-(1A and 1P) or the corresponding 1-vinyl-compounds (2A and 2P). From these, alkyl-dimethyl-chlorosilanes 3A3-3A18 could then be prepared in good yield by reaction of the Grignard derivative of the alkyl-bromides lA3-lAls with dimethyl-dichloro-silane according to reaction (1) [4] [5]:This reaction was not efficacicus for introduction of oxaalkyl substituents. In our attempts to prepare 3 P g in tetrahydrofuran (THF) by reaction (l), a complex mixture resulted, probably because the chlorosilane attacked the solvent, as it is known that dimethyl-dichloro-silane can attack the ether-C-0 bond [6]. In replacing dichlorosilane by dimethyl-diethoxy-silane, the ethoxysilane 4Pg could be isolated from the reaction mixture in good yield.

Design and Fabrication of a Flexible and Self‐Supporting Supramolecular Film by Hierarchical Control of the Interaction between Hydrogen‐Bonded Sheet Assemblies

“…2 was prepared according to the procedure reported previously for similar compounds 9. 4,7‐Dioxaoct‐1‐ene9a (8.12 g, 70 mmol) and a small amount of H 2 PtCl 6 (<1 mg) was heated to 100 °C in an N 2 atmosphere. Chlorodiisopropylsilane (10 mL, 59 mmol) was added dropwise and the mixture stirred overnight.…”

Recent Developments in the Synthesis and Structure of Organosilanols

“…Monosilanols are the largest family of silanols. These are of three types: (a) R 3 SiOH [e.g., Me 3 SiOH, − Et 3 SiOH, ,, n -Bu 3 SiOH, , t -Bu 3 SiOH, s -Bu 3 SiOH, ( c -C 6 H 11 ) 3 SiOH, , Ph 3 SiOH, ,, (1-naphthyl) 3 SiOH, ( t -BuO) 3 SiOH, ,− (Me 3 SiO) 3 SiOH, (PhMe 2 SiO) 3 SiOH, ( neo -C 5 H 12 O) 3 SiOH]; (b) R 2 R‘SiOH [e.g., Me 2 EtSiOH, t -Bu 2 MeSiOH, ( n -C 6 H 11 )Me 2 SiOH, (SiMe 3 ) 3 C(Me) 2 SiOH, , (SiMe 3 ) 3 C(Et) 2 SiOH, t -Bu 2 SiClOH, t -Bu 2 SiBrOH, t -Bu 2 Si(NH 2 )OH, (PhCHCl)Me 2 SiOH, (PhCHBr)Me 2 SiOH, ( t -Bu 2 MeSiO) 2 SiFOH, , (Me 3 SiO) 2 (PhMe 2 SiO)SiOH, (Me 3 SiO)(PhMe 2 SiO) 2 SiOH, [MeO(CH 2 ) 2 O(CH 2 ) 4 ]Me 2 SiOH, (PhMe 2 Si) 3 CSiMe 2 OH, [(Me 3 SiO)(Me 2 SiO)] 2 SiMeOH, [(SiMe 3 ) 2 C(SiMe 2 Br)]SiMe 2 OH, ( neo -C 5 H 11 O)Me 2 SiOH]; (c) RR‘R‘ ‘SiOH [e.g., PhMe(1-naphthyl)SiOH, (SiMe 3 ) 3 CSi(Ph) (OMe)OH, (PhMe 2 Si) 3 CSi(Me)(H)OH, (Cp*(CO) 2 Fe)Si( p -tolyl)(H)OH, (Cp(CO) 2 Fe)Si( i -Pr)(H)OH, (Cp*(CO) 2 (PMe 3 )Fe)SiMe(H)OH 61 ] etc. Examination of all of these silanols reveals that the Si−OH group is reasonably robust and present in various types of compounds which contain many types of bonds such as Si−C, Si−H, Si−M, Si−O, Si−F, Si−Cl, Si−I or Si−Br.…”

Monofunctional (Dimethylamino)silane as Silylating Agent

“…6.14. Chlorodimethyl(4-oxupentyljsilane (Im") and chloro(4.7-dioxaoctyljdimethylsilane (In") were prepared according to [23]; the crude product was used immediately after preparation.…”