Heterogeneous Organocatalysts for the Reduction of Carbon Dioxide with Silanes

Abstract

The utilization of carbon dioxide (CO 2) as feedstock for chemical industries is gaining interest as a sustainable alternative to nonrenewable fossil resources. However, CO 2 reduction is necessary to increase its energy content. Hydrosilane is a potential reducing agent that exhibits excellent reactivity under ambient conditions. CO 2 hydrosilylation yields versatile products such as silylformate and methoxysilane, whereas formamides and N-methylated products are obtained in the presence of amines. In these transformations, organocatalysts are considered as the more sustainable choice of catalyst. In particular, heterogeneous organocatalysts featuring precisely designed active sites offer higher efficiency due to their recyclability. Herein, an overview is presented of the current development of basic organocatalysts immobilized on various supports for application in the chemical reduction of CO 2 with hydrosilanes, and the potential active species parameters that might affect the catalytic activity are identified.

Catalytic reduction and reductive functionalisation of carbon dioxide with waste silicon from solar panel as the reducing agent

“…The use of hydrosilane or molecular hydrogen for reductive functionalisation is well known. 23 However, this is the first report on reductive functionalisation using powdered Si wafer, a waste material, as the reducing agent.…”

“…S2, ESI†) indicates the coupling of 13 C– 1 H through a split of the formyl peak around 8 ppm with J 1H–13C = 215 Hz. 20,23 A similar experiment of formic acid synthesis was performed using 10 mmol of D 2 O (>99.8 atom% D) instead of H 2 O in typical experiments, in order to confirm the source of proton. After 24 h, the reaction mixture was examined using 2 H NMR, where the formic acid- d showed a clear peak at 7.82 ppm (Fig.…”

有機分子触媒もしくは金属触媒を用いた二酸化炭素変換反応

“…Carbon Dioxide Utilization by Using Organic or Metal Catalysts lysts 14) have also been actively investigated 11) . Simple fluoride or carbonate salts also act as high-activity catalysts in the reaction 15) .…”

Mild Synthesis of a Dimethoxy‐Terminated Siloxane through a Ring‐Opening Reaction

“…[1j] The gradual reduction of CO 2 with hydrosilanes can generate silylformate, bis(silyl)acetal, methoxysilane and CH 4 in sequence. [2] Methoxysilane can be obtained with high selectivity by controlling the reaction conditions (Scheme 1 (a)). [3] However, most of the hydrosilylation reactions of CO 2 require high CO 2 pressure and expensive transition metal catalysts.…”