Iron-Catalyzed Chlorination of Silanes

Abstract

A simple and highly efficient iron-catalyzed method for the chlorination of silanes has been developed. By use of 0.5−2% of the Fe(III)based catalyst FeCl 3 or Fe(acac) 3 in the presence of 1−1.5 equiv of acetyl chloride as the chlorine donor, a large number of silanes, alkoxysilanes, and silanols were converted to the corresponding chlorosilanes in 50−93% yields. In contrast to earlier reported methods often suffering from expensive catalysts or use of stoichiometric metal salts, hazardous reagents, and reaction conditions, the presently described methodology allows benign reaction conditions and simple workup while using only catalytic amounts of a readily available and economically viable iron catalyst.

B(C6F5)3 catalysis accelerates the hydrosilane chlorination by Ph3CCl

“…The same catalyst was utilized for the chlorination of polysiloxane bearing pendant Si‐H bonds by CCl 4 . In recent years a shift to cheaper non‐precious metal catalysts is observed and thus Leino published the use of iron salts (FeCl 3 , Fe (acac) 3 ) in combination with acyl chlorides as an efficient system for hydrosilane chlorination . Authors developed a mechanism different to the one described in Scheme , the chloride atom is transferred from either the activated acyl chloride or acetaldehyde‐FeCl 3 adduct and the acyl chloride is gradually reduced to acetaldehyde and ethylacetate .…”

Kinetic and Theoretical Investigation of Iron(III)‐Catalyzed Silane Chlorination

“…Besides on the catalyst loading, the initial reaction rate was also shown to depend on the concentration of the chlorinating agent (1.0–1.5 equivalents). Kinetic modeling was then performed by using the experimental data obtained, based on the earlier proposed reaction mechanism shown in Scheme . Derivation of the rate equation is briefly presented below.…”

“…In our earlier work, the iron‐catalyzed chlorination was tentatively proposed to proceed as shown in Scheme . As a continuation of the previous study, and in order to elucidate the true mechanism of this practical iron‐catalyzed reaction, we herein report detailed experimental kinetic studies on the reaction system, combined with molecular modeling, and using triphenylsilane and triisopropylsilane as the model substrates.…”

“…In silicon chemistry, Voronkov and co‐workers reported in 1986 the formation of chlorosilanes as a side product in the ferric acetylacetonate catalyzed reaction of carboxylic acid chlorides to esters and aldehydes . Inspired by these earlier efforts in the field, we recently developed and reported a highly versatile, robust, and efficient methodology for the chlorination of silanes, methoxysilanes, and silanols using low loadings of FeCl 3 or Fe(acac) 3 (acac=acetylacetonato) catalysts in the presence of 1–1.5 equivalents of acetyl chloride as the chlorine source (Scheme ) …”

Introducing Students to Feedstock Recycling of End-of-Life Silicones via a Low-Temperature, Iron-Catalyzed Depolymerization Process

“…After 1 h, the products were obtained in sufficient yield (63− 72% student and 90% advisor yield) and purity for characterization by 1 H, 13 C{ 1 H}, 19 F, and 29 Si{ 1 H} NMR spectroscopy. Depending on the NMR instrumentation available or cost of NMR time, suitable characterization can be done with 1 H and 19 F NMR data, especially the coupling between 1 H and 19 F, as well as 29 Si, allows students to learn new tools about characterization of chemicals. For instance, 3 30 and 4 31 can be easily distinguished by the different coupling pattern ( Table 1).…”