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1.
<正>The metal-free combination of catalytic amounts of PPh_3,B(C_6F_5)_3,and PhSiH_3 can efficiently hydrosilylate aldehydes, ketones,aldimines and ketimines to afford the corresponding reduction products in good yields. 相似文献
2.
A simple and convenient procedure for the reduction of aldehydes and ketones with sodium borohydride activated by solid acids such as boric acid, benzoic acid, and p-toluenesulfonic acid monohydrate under solvent-free conditions is described. 相似文献
3.
Sm(i-PrO)3/4A分子筛催化下醛、酮的Meerwein-ponndorf-Verley型还原反应 总被引:1,自引:1,他引:0
Sm(i-Pro)3(2%)/4A分子筛能够有效地催化各类醛、酮的Meerwein-Ponndorf-Verley型还原反应, 反应转化率优良。 相似文献
4.
Indium tri(isopropoxide)-catalyzed Meerwein-Ponndorf-Verley reduction of aliphatic and aromatic aldehydes in 2-propanol gave selectively the corresponding primary alcohols in good to excellent yields at room temperature. A wide range of functional groups including alkene, ether, ketone, ester, nitrile, and nitro were tolerated under the optimum reaction conditions. Chemoselective reductions were also achieved not only between aromatic aldehyde, aromatic ketone, and epoxide but also between aliphatic aldehyde and alkene. 相似文献
5.
Sodium hydride-promoted catalytic hydroboration of aldehydes and ketones with pinacolborane (HBpin) was examined, and 10?mol% of NaH was found to cause the HBpin to participate in hydroboration in a convenient and efficient manner at mild reaction conditions. Further chemoselective hydroboration of aldehyde over ketone functionality was also analyzed. In addition, no hydroboration was observed form ester, acyl chloride, amide, nitrile, alkene, alkyne, alkyl halide and epoxide functional groups indicate that present system (HBpin, NaH) is highly selective for aldehydes and ketones. 相似文献
6.
7.
Sominsky L Rozental E Gottlieb H Gedanken A Hoz S 《The Journal of organic chemistry》2004,69(5):1492-1496
When a solution of a carbonyl compound in alcohol (primary or secondary) is heated to ca. 300 degrees C, a disproportionation reaction, in which a carbonyl compound is reduced to the corresponding alcohol and the alcohol is oxidized to the corresponding ketone, takes place. This uncatalyzed variation of the Meerwein-Ponndorf-Oppenauer-Verley reaction gives, in certain cases, e.g., reduction of acetophenone or benzaldehyde by i-PrOH, almost quantitative yields. Yields are higher with secondary alcohols such as i-PrOH than with a primary alcohol such as EtOH. The reactions were also performed in a flow system by passing at a slow rate the same solutions through a glass or a metal coil heated to elevated temperatures. Ab initio calculations performed at the B3LYP/6-31G* level show that thermodynamically i-PrOH is a more potent reducing agent than EtOH by ca. 4 kcal/mol. The computations also show that in cases of aromatic carbonyl compounds, part of the deriving force is obtained from the entropy change of the reaction. The major contributor to the high yield, however, is the excess alcohol used, which shifts the equilibrium to the right. Calculated entropy of activation as well as isotopic H/D labeling suggest a cyclic transition state. 相似文献
8.
Akira Watanabe 《Tetrahedron letters》2004,45(33):6229-6233
Oxovanadium(V)(salen) complex 4 was found to catalyze Meerwein-Ponndorf-Verley cyanation of aliphatic aldehydes with good to high enantioselectivity. This cyanation showed a positive nonlinear effect. 相似文献
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10.
Glenn C. Andrews 《Tetrahedron letters》1980,21(8):697-700
Ammonia borane and primary amine boranes are highly chemoselective reducing agents for aldehydes and ketones. 相似文献
11.
《Tetrahedron letters》1988,29(31):3741-3744
Various aromatic aldehydes and ketones were reduced to the corresponding hydrocarbons using ammonium formate as the hydrogen source. 相似文献
12.
S. Huwyler 《Microchemical Journal》1976,21(2):135-139
The lithium aluminum hydride reduction of 1 ng of the aldehyde, decanal and of the ketone, 2-decanone is described. The method should be applicable to further classes of compounds amenable to reduction by complex hydrides. 相似文献
13.
Investigation of polarographic reduction of ethacrynic acid (I) in 2% and 60% ethanolic solutions showed that acid I is, similarly to other α,β-unsaturated ketones, reduced first on the CC bond. But the presence of acid-base equilibria for one two-electron reduction wave in the medium pH range, as well as the sensitivity of the reduction wave of the aryl alkyl ketone to the presence of borates and carbonates, makes this reduction process different. Ethacrynic acid proved to be a suitable model compound for the study of addition reactions to a CO-CC system. Preliminary examination of the reaction of ethylamine indicated that Schiff base rather than Mannich base is formed. A 60% ethanolic solution at pH 6–10 or with 1 M ethylamine half-titrated with hydrochloric acid, provided the most suitable conditions for analytical purposes. 相似文献
14.
The complexes formed by the reaction of [Ti(OiPr)(4)] and bicyclo-octanediols (BODOLs) 1 and 2 (1:1) are useful as chiral catalysts in asymmetric reductions and were investigated by (1)H NMR spectroscopy and computational methods. A consistent picture emerged of head-to-tail dimers being kept together via a Ti-O-Ti-O micro-oxo bridge similar to the Ti-tartrates but different from the corresponding Ti-BINOLates and Ti-TADDOLates. 相似文献
15.
The Mannich reaction with methylene- and benzylidenediacetophenones has given: 1,3-dibenzoyl-4-piperidinobutane, 1,3-dibenzoyl-4-morpholinobutane, 1,3-dibenzoyl-4-diethylamino-2-phenylbutane, 1,3-dibenzoyl-2-phenyl-4-piperidinobutane, 1,3-dibenzoyl-4-diethylaminobutane, and 1,3-dibenzoyl-4-dimethylamino-2-phenylbutane. From the latter two compounds, 3-diethylaminomethyl-2,6-diphenylpyridine and 3-dimethylaminomethyl-2,4,6-triphenylpyridine have been obtained.For part XVII, see [7]. 相似文献
16.
Allylboronates derived from 3,3'-disubstituted 2,2'-binaphthols react with aldehydes and ketones to give the expected allylated products with up to >99:1 er. Highest selectivities were observed for aromatic ketones. The bis(trifluoromethyl) derivative is particularly outstanding in terms of reactivity, selectivity, and robustness. [reaction: see text] 相似文献
17.
V. G. Kharchenko N. M. Kupranets M. N. Tilichenko 《Chemistry of Heterocyclic Compounds》1970,4(1):10-11
The alkaline condensation of -aceto-and -propionaphthalenes with furfural has given, respectively, 2-(-furfuryl)-1, 3-di(-naphthoyl)-propane and 3-(-furyl)-2,4-di(-naphthoyl)pentane; both -diketones have also been obtained by the Michael condensation. Under more severe conditions, two molecules of furfural condense with three molecules of -acetonaphthalene to form 2, 4-di(-furyl)-1, 3, 5-tri(-naphthoyl)pentane. Under similar conditions, benzaldehyde exhibits only a feeble capacity for triketone condensation with -acetonaphthalene. The condensation of -propionaphthalene with furfural has given the new compound furylidenepropionaphthalene. It has been shown that both under the conditions of the improved Chichibabin pyridine synthesis and under the conditions of the Leuckhardt reaction, 3-(-furyl)-1, 3-di(-naphthoyl)propane gives 4-(-furyl)-2, 6-di(-naphthyl)pyridine. 相似文献
18.
Acetone is catalytically reduced to isopropyl alcohol by carbon monoxide and water in the presence of iron carbonyls and triethylamine at 100°C and 100 bar. Use of NaOH in place of triethylamine gives a much less efficient catalyst system. The Et3NH·HFe(CO)4 system also catalyses the reduction of n-butyraldehyde to n-butyl alcohol at room temperature in a fast stoichiometric reaction, whereas NaHFe(CO)4 is inactive under the same conditions. The Et3NH+ cation is necessary for the transfer of a proton to the carbonyl group, while the HFe(CO)4? anion carries out nucleophilic attack on carbonyl group and supplies the hydride ion. 相似文献
19.
V. G. Kharchenko N. M. Kupranets M. N. Tilichenko 《Chemistry of Heterocyclic Compounds》1968,4(1):10-11
The alkaline condensation of β-aceto-and β-propionaphthalenes with furfural has given, respectively, 2-(α-furfuryl)-1, 3-di(β-naphthoyl)-propane and 3-(α-furyl)-2,4-di(β-naphthoyl)pentane; both δ-diketones have also been obtained by the Michael condensation. Under more severe conditions, two molecules of furfural condense with three molecules of β-acetonaphthalene to form 2, 4-di(α-furyl)-1, 3, 5-tri(β-naphthoyl)pentane. Under similar conditions, benzaldehyde exhibits only a feeble capacity for triketone condensation with β-acetonaphthalene. The condensation of β-propionaphthalene with furfural has given the new compound furylidenepropionaphthalene. It has been shown that both under the conditions of the improved Chichibabin pyridine synthesis and under the conditions of the Leuckhardt reaction, 3-(α-furyl)-1, 3-di(β-naphthoyl)propane gives 4-(α-furyl)-2, 6-di(β-naphthyl)pyridine. 相似文献