Synthesis of titanium tetraalkoxides from hydrous titanium dioxideand dialkyl carbonates

Abstract

The reaction of hydrous titanium dioxide (TiO 2•nH 2 O, n=0.15-1.23) and dialkyl carbonates at 453-573 K offers a convenient synthetic method for titanium tetraalkoxides which are free from chlorine-containing impurities. Thus, hydrous titanium dioxide was almost completely converted into Ti(OEt) 4 by its reaction with diethyl carbonate at 493 K for 16 h. The reaction proceeded faster in the presence of a sodium hydroxide catalyst. From the hydrous titanium dioxide and dipropyl carbonate, Ti(OPrn) 4 was obtained in a high yield.

Halogen‐Free Synthesis of Carbamates from CO2 and Amines Using Titanium Alkoxides

“…Ono et al. reported a synthesis of Ti(OEt) 4 ( 3 ) from titanium dioxide hydrate (TiO 2 ⋅ x H 2 O) using diethyl carbonate (DEC) as the dehydrating agent over 16 h at 260 °C; however, DEC must be synthesized separately, resulting in a multistep reaction process.…”

“…The process involved in regenerating the metal alkoxide from am etal oxide or hydroxide in the presence of ad ehydrating agent is known. [9,11] Ono et al reported as ynthesis of Ti(OEt) 4 (3)f rom titanium dioxide hydrate (TiO 2 ·xH 2 O) using diethylc arbonate (DEC) as the dehydrating agent over 16 ha t2 60 8C; [11b] however, DEC must be synthesized separately,r esulting in am ultistep reaction process.…”

Synthesis of organic carbamates as polyurethane raw materials from CO2: the quest for metal alkoxides as regenerable reagents

“…56 Ono et al reported that Ti(OR′) 4 can be obtained by the reaction of dialkyl carbonate on hydrated titanium dioxide with the Ti–OH moiety, and this reaction should also be helpful for the regeneration and reuse of Ti(OR′) 4 . 58 Furthermore, Ti(OR′) 4 has low toxicity, is easy to handle, and does not undergo disproportionation reactions unlike dialkyltin dialkoxide. Based on the above, we investigated the synthesis of organic carbamates from CO 2 and amines using Ti(OR′) 4 .…”

Formation of hollow silica spheres with ordered mesoporous structure by treatment with dimethyl carbonate for selective decomposition of mesoporous silica core

“…Metal oxides react with dimethyl carbonate (DMC) to afford metal methoxides [30][31][32]. For example, silica is decomposed by the reaction with DMC using an alkali metal salt catalyst to form tetramethoxysilane and carbon dioxide [30,31].…”