Reversible CO₂ Addition to a Si=O Bond and Synthesis of a Persistent SiO₂–CO₂ Cycloadduct Stabilized by a Lewis Donor–Acceptor Ligand

Abstract

The donor-stabilized sila-β-lactone 1 reacts with CO via a remarkable reversible [2+2]-cycloaddition reaction to form the spiro-cyclic silicon carbonate derivative 2. Furthermore, photolysis of 2 under pressure of CO affords the first persistent SiO -CO cycloadduct 3, presenting a Si O -like structure, which is stabilized by a Lewis donor-acceptor type ligand. As predicted by theoretical calculations, in marked contrast to the thermodynamically stable SiO dimer, the SiO -CO mixed cycloadduct 3 is labile and readily releases CO .

Disilene–Silylene Interconversion: A Synthetically Accessible Acyclic Bis(silyl)silylene

“…Despite this challenge, the SiO moiety could be tamed , and a series of donor- ,, and donor–acceptor-stabilized , heavier carbonyl compounds have been reported. Even a few examples of donor-free, three-coordinate silanones (silicon analogues of ketones) have been isolated. , Nevertheless, silanoic esters, the heavier congeners of carboxylate esters, remain rather elusive compounds with scarcely any reported example species …”

Nachweis des Lewis‐amphoteren Charakters von Tris(pentafluorethyl)silanid, [Si(C2F5)3]−

“…[40] Die meisten Silylene bilden dimere Spezies wie beispielsweise Verbindung IV, [41] während nur einige wenige von ihnen zu Verbindungen wie V-VIII mit chelatisierenden Carbonatliganden führen (Abbildung 6). [42] Wenn ein [Si(C 2 F 5 ) 3 ] À -Salz mit einem Überschuss an CO 2 umgesetzt wird, wird das entsprechende Siliciumcarbonat 3 erhalten (Schema 5). Die Bildung von CO wurde durch IR-spektroskopische Untersuchungen der Gasphase nachgewiesen.…”

The Quest for Stable Silaaldehydes: Synthesis and Reactivity of a Masked Silacarbonyl

“…Recenty ears have witnessed considerable advancesi nt he isolation of monomeric silacarbonylcompounds including silanones (R 2 SiO) and silanoic acid (RSi(O)OH) derivatives. [3][4][5][6][7][8][9] Rational steric and electronic protection, Lewis base or Lewis base/acid complex formation are the key approaches to achieve the required stabilization. [3][4][5][6][7][8][9][10] Nevertheless, despite this success, our knowledge aboutt he reactivity of silicon analogues of carbonyl compounds and their synthetic potential remains limited.…”