7510-30-7Relevant academic research and scientific papers
Novel Si(II)+and Ge(II)+Compounds as Efficient Catalysts in Organosilicon Chemistry: Siloxane Coupling Reaction ?
Fritz-Langhals, Elke,Kneissl, Sotirios,Piroutek, Phillip,Werge, Sven
, (2020/09/02)
Novel catalytically active cationic Si(II) and Ge(II) compounds were synthesized and isolated in pure form. The Ge(II)+-based compounds proved to be stable against air and moisture and therefore can be handled very easily. All compounds efficiently catalyze the oxidative coupling of hydrosil(ox)anes with aldehydes and ketones as oxidation reagents and simultaneously the reductive ether coupling at very low amounts of 0.01 mol %. Because the catalysts also catalyze the reversible cyclotrimerization of aldehydes, paraldehyde can be used as a convenient source for acetaldehyde in siloxane coupling. It is shown that the reaction is especially suitable to make siloxane copolymers. Moreover, a new fluorine-free weakly coordinating boronate anion, B(SiCl3)4-, was successfully combined with the Si(II) and Ge(II) cations to give the stable catalytically active ion pairs Cp*Si:+B(SiCl3)4-, Cp*Ge:+B(SiCl3)4-, and [Cp(SiMe3)3Ge:+]B(SiCl3)4-.
A convenient approach for the synthesis of 1,3,5-trioxanes under solvent-free conditions at room temperature
Li, Xinzhong,Lin, Qi,Cao, Rong
, p. 1017 - 1022 (2014/06/09)
A series of environmentally benign bis-SO3H-functionalized Bronsted acidic ionic liquids were synthesized by using aliphatic polyamines and 1,3-propanesultone as the source chemicals. These ionic liquids acted as efficient inexpensive and recyclable catalysts for cyclotrimerization of aliphatic aldehydes at room temperature under solvent-free conditions. The reactions proceeded smoothly with good to excellent isolated yields (66.9-97.6 %=) and were generally complete in 1.5 h when the amount of ionic liquids was 0.1 mol%. The ionic liquids could be recovered readily and reused five times without any significant loss in their catalytic activity. Graphical abstract: [Figure not available: see fulltext.]
Novel acidic ionic liquids as efficient and recyclable catalysts for the cyclotrimerization of aldehydes
Song, Heyuan,Chen, Jing,Xia, Chungu,Li, Zhen
experimental part, p. 266 - 273 (2011/10/31)
A mild, efficient, and ecofriendly procedure for cyclotrimerization of aldehydes was realized by using a series of novel Brnsted acidic ionic liquids (BAILs) consisting of double-SO3H groups in cations as catalysts. Good conversion of aldehydes and selectivity of trialkyl-1,3,5-trioxanes were achieved by using 1mol% of BAILs. In addition, the catalyst system could be recycled and reused at least eight times without apparent loss of activity. Taylor & Francis Group, LLC.
Cyclotrimerization of Aliphatic Aldehydes Catalysed by Keggin-type Heteropoly Acids and Concomitant Phase Separation
Sato, Satoshi,Furuta, Hiromi,Sodesawa, Toshiaki,Nozaki, Fumio
, p. 385 - 390 (2007/10/02)
The acid-catalysed cyclotrimerization of aliphatic aldehydes has been examined through comparison of heteropoly acids with other acid catalysts.A Keggin-type heteropoly acid such as phosphomolybdic acid catalyses the cyclotrimerization of aldehydes, such as ethanal, propanal, butanal, 2-methylpropanal, 2,2-dimethylpropanal, hexanal, octanal, and decanal, to produce the respective 2,4,6-trialkyl-1,3,5-trioxanes in high yields.Catalysts turnover number of the heteropoly acid is more than 10000 for propanal cyclotrimerization.In addition to the high catalytic activities, the reaction mixture spontaneously separates into two phases, a produ ct phase and a catalyst phase, at high conversions of aldehyde.For propanal cycltrimerization, the reaction mixture separates into two liquid phases, and the recovered catalyst phase may be repeatedly applied to the reaction without additional care in isolation of the catalyst.The phase separation phenomenon has been concluded to be caused by the insolubility of the heteropoly acid coordinated with propanal in the product 2,4,6-triethyl-1,3,5-trioxane.
Process for the manufacture of cyclic acetals of aliphatic aldehydes
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, (2008/06/13)
A process for preparing a cyclic acetal from a saturated, aliphatic aldehyde comprises contacting a saturated, aliphatic aldehyde of 2-16 carbon atoms with a silica gel.
