- Beryllium-Induced Conversion of Aldehydes
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Aldehydes play a key role in the human metabolism. Therefore, it is essential to know their reactivity with beryllium compounds in order to assess its effects in the body. The reactivity of simple aldehydes towards beryllium halides (F, Cl, Br, I) was studied through solution and solid-state techniques and revealed distinctively different reactivities of the beryllium halides, with BeF2 being the least and BeI2 the most reactive. Rearrangement and aldol condensation reactions were observed and monitored by in situ NMR spectroscopy. Crystal structures of various compounds obtained by Be2+-catalyzed cyclization, rearrangement, and aldol addition reactions or ligation of beryllium halides have been determined, including unprecedented one-dimensional BeCl2 chains and the first structurally characterized example of an 1-iodo-alkoxide. Long-term studies showed that only aldehydes without a β-H can form stable beryllium complexes, whereas other aldehydes are oligo- and polymerized or decomposed by beryllium halides.
- Müller, Matthias,Buchner, Magnus R.
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p. 11147 - 11156
(2019/08/12)
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- InCl3 as an efficient catalyst for cyclotrimerization of aldehydes: Synthesis of 1,3,5-Trioxane under solvent-free conditions
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1,3,5-Trioxanes derived from aldehydes were synthesized using indium trichloride as a catalyst. Cyclotrimerization of the aldehydes gave excellent yields under neat conditions within a short span of time. Copyright Taylor & Francis, Inc.
- Elamparuthi,Ramesh,Raghunathan
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p. 2801 - 2804
(2007/10/03)
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- A convenient solvent-free preparation of 1,3,5-trioxanes
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In the presence of a small amount of trimethylsilyl chloride, aldehydes gave at room temperature in solvent-free conditions the corresponding 1,3,5-trioxanes with good to excellent yields.
- Augé, Jacques,Gil, Richard
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p. 7919 - 7920
(2007/10/03)
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- Brominative Deoxygenation of Some Aldehydes and Ethers
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Three aldehydes (4a-c) are transformed into 1,1-dibromides (6a-c) by 2,2,2-tribromo-2,2-dihydro-1,3,2-benzodioxaphosphole (2).This reagent (2) is also very active in the cleavage of ethers; its reactions may show some features of carbonium as well as of SN2 character.
- Roman, Ulrich von,Knorr, Rudolf,Behringer, Claudia,Ruhdorfer, Jakob
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p. 260 - 262
(2007/10/02)
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- Cyclotrimerization of Aliphatic Aldehydes Catalysed by Keggin-type Heteropoly Acids and Concomitant Phase Separation
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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.
- Sato, Satoshi,Furuta, Hiromi,Sodesawa, Toshiaki,Nozaki, Fumio
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p. 385 - 390
(2007/10/02)
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