Reduction by tributyltin hydride of carbonyl compounds adsorbed on silica gel: selective reduction of aldehydes

1978 ◽  
Vol 43 (20) ◽  
pp. 3977-3979 ◽  
Author(s):  
Norman Y. M. Fung ◽  
Paul De Mayo ◽  
J. Herman Schauble ◽  
Alan C. Weedon
Keyword(s):  
Silica Gel ◽  
Carbonyl Compounds ◽  
Selective Reduction ◽  
Tributyltin Hydride

Selective reduction of less reactive carbonyl groups in the presence of diborane and sodium bisulfite on silica gel

1990 ◽  
Vol 68 (5) ◽  
pp. 720-724 ◽  
Author(s):  
Teiji Chihara ◽  
Tamie Wakabayasi ◽  
Kazuo Taya ◽  
Haruo Ogawa
Keyword(s):  
Carbonyl Group ◽  
Carbonyl Compound ◽  
Silica Gel ◽  
Carbonyl Compounds ◽  
Selective Reduction ◽  
Aromatic Aldehydes ◽  
Sodium Bisulfite ◽  
Carbonyl Groups ◽  
Selective Reaction ◽  
Reactive Carbonyl

The less reactive carbonyl group of a mixture of reducible groups of carbonyl compounds was preferentially reduced with diborane on silica gel by first forming an adduct of the more reactive carbonyl group with sodium bisulfite. For example, 4-acetylbenzaldehyde could be converted to 4-(1-hydroxylethyl)benzaldehyde in 93% selectivity; in a mixture of 4-phenyl-acetophenone and 4-phenylbenzaldehyde, biphenylethanol was preferentially formed in 95% yield with 16% yield of 4-phenylbenzyl alcohol. Silica gel and sodium bisulfite were essential for this selective reaction. Aliphatic and aromatic aldehydes and unhindered cyclohexanones could be selectively protected by this method. Keywords: sodium bisulfite, silica gel, carbonyl compound, selective reduction, diborane.

HNO3/Silica Gel supported CAN; Oxidative Deprotection of Benzylic Tetrahydropyranyl Ethers under Solvent-free Conditions using Microwaves

2005 ◽  
Vol 2005 (2) ◽  
pp. 105-106 ◽  
Author(s):  
Majid M. Heravi ◽  
Pegah Kazemian ◽  
Hossein A. Oskooie ◽  
Mitra Ghassemzadeh
Keyword(s):  
Ammonium Nitrate ◽  
Silica Gel ◽  
Carbonyl Compounds ◽  
Solvent Free ◽  
Cerium Ammonium Nitrate ◽  
Solvent Free Conditions ◽  
Cerium Ammonium

Benzylic tetrahydropyranyl ethers are rapidly and selectively oxidised to the corresponding carbonyl compounds by HNO3/ silica gel supported cerium ammonium nitrate (CAN) under solvent free conditions using microwave.

Caro?s Acid Supported on Silica Gel. Part 6. A Mild Reagent for Regeneration of Carbonyl Compounds from Acetals, Ketals, and 1,1-Diacetates.

ChemInform ◽  
2005 ◽  
Vol 36 (18) ◽  
Author(s):  
M. M. Lakouraj ◽  
M. Tajbakhsh ◽  
V. Khojasteh ◽  
M. H. Gholami
Keyword(s):  
Silica Gel ◽  
Carbonyl Compounds

DEVELOPMENT OF MODIFIED SORBENT FOR INCREASE IN EFFICIENCY OF ADSORPTIVE PURIFICATION OF CORN OIL

2019 ◽  
Author(s):  
К.К. ДАВЫДОВ
Keyword(s):  
Silica Gel ◽  
Carbonyl Compounds ◽  
Methylene Chloride ◽  
Corn Oil ◽  
Amino Groups ◽  
Absorption Bands ◽  
Temperature Method ◽  
Version 2.0 ◽  
Surface Silica ◽  
Production Conditions

Проведена модификация сорбента, повышающего эффективность адсорбционной очистки кукурузного масла. Для получения сорбента использовали силикагель с поверхностью 300 м2/г, в качестве модификатора – гамма-аминопропилтриэтоксисилан из расчета 4 аминогруппы на 1 нм2поверхности. Силикагель (СГ) перед модификацией высушивали до постоянной массы. Навеску СГ диспергировали в разных органических растворителях – н-гексане, хлороформе и хлористом метилене – и вносили модификатор. Реакцию проводили при перемешивании реакционной смеси в ротационном вакуумном испарителе. Далее растворитель отделяли декантированием и промывали осадок. Остатки растворителя отгоняли под вакуумом. Полученный модифицированный СГ высушивали при заданной температуре. Для подтверждения модификации применяли метод ИК-спектроскопии с преобразованием Фурье на спектрометре FSM-1201. Для первичной обработки спектров использовали программное обеспечение F-Spec, для отнесения полос поглощения – IR Pal версии 2.0. С целью проверки способности синтезированного сорбента к сорбции карбонильных соединений использовали кукурузное масло, полученное в производственных условиях, после отбелки, с высоким значением анизидинового числа (около 8). Установлено, что использование модифицированного СГ значительно повышает эффективность адсорбционной очистки кукурузного масла: анизидиновое число масла, обработанного модифицированным сорбентом, снижается до 8 раз по сравнению с аналогичным показателем масла, обработанного немодифицированным СГ; на величину изменения анизидинового числа влияет дозировка модифицированного сорбента; свойства растворителя, в котором проводилась модификация, не оказывают существенного влияния на активность сорбента. Modification of the sorbent, which increases the efficiency of adsorption purification of corn oil, was carried out. Silica gel with a surface 300 m2/g was used to produce a sorbent, as a modifier – gamma-aminopropyltriethoxysilane at the rate of 4 amino groups per 1 nm2 surface. Silica gel (SG) before modification was dried to a constant mass. The sample of SG is dispersed in different organic solvents – n-hexane, chloroform and methylene chloride – and the modifier was introduced. Further, the solvent was separated by decanting, and the precipitate was washed. Residues of solvent are removed under vacuum. The obtaining modified SG was dried at a given temperature. Method of IR-spectroscopy with transform Fourier on the FSM-1201 spectrometer is used to confirm the modification. Software F-Spec is used for primary processing of spectra, IR Pal version 2.0 – for assignment of absorption bands. Corn oil obtained in production conditions, after bleaching, with a high anisidine number (about 8) was used to test the ability of the synthesized sorbent to sorption of carbonyl compounds. It was found that the use of modified SG significantly increases the efficiency of adsorption purification of corn oil: the anisidine number of oil treated with a modified sorbent is reduced to 8 times compared to the same indicator of oil treated with unmodified SG; the dosage of the modified sorbent affects the amount of change in the anisidine number; the properties of the solvent, in which the modification was carried out, do not have a significant effect on the activity of the sorbent.

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