Asymmetric Direct Aldol Reaction of Cyclohexanone Catalyzed by( N'-Benzyl-N'-D-prolyl)-trans-4-hydroxy-L-proline Hydrazide

A new proline catalyst, namely (N′‐benzyl‐N′‐D‐prolyl)‐trans‐4‐hydroxy‐L‐proline hydrazide, has been prepared and proved to be a superior catalyst for the asymmetric aldol reaction of cyclohexanone and aromatic aldehydes, affording up to 98:2 dr and 98% ee.     

Side Reactions in the Liquid-Phase Cyclohexanone Ammoximation

Influence of metal ions on hydrogen peroxide decomposition on the liquid-phase ammoximation of cyclohexanone was studied in homogeneous and heterogeneous (over titanium silicalite) conditions. The latter reaction is accompanied by side reactions, which deactivate the catalyst. Deactivation behavior is discussed.     

2-乙氧羰基-3-甲基-4,5-四亚甲基吡咯的合成

以乙酰乙酸乙酯(1)为原料,在醋酸中与亚硝酸钠通过肟化反应制得N-羟基亚胺乙酰乙酸乙酯(2);2在醋酸缓冲溶液中经锌粉还原后与环己酮加成环化合成了2-乙氧羰基-3-甲基-4,5-四亚甲基吡咯(3),其结构经1H NMR,IR和元素分析表征。较适宜的反应条件为:1100 mmol,n(Zn)∶n(1)=2.9∶1.0,在醋酸中回流反应,总收率39%;以多步反应的最佳反应条件进行"一锅煮"合成3,收率50%。     

应用正交试验确定环已醇最佳工艺条件

应用正交试验确定环已醇最佳工艺条件．本文采用正交试验的方法，对锦西化工总厂环已酮车间利用环已醇脱氢生产环已酮的生产工艺过程进行了正交试验设计，应用方差分析方法得出了最佳生产工艺条件，同时给出了经济效益分析评价     

Synthesis and Crystal Structure of（2E,6E）-2,6-bis（2,3-dimethoxybenzylidene）cyclohexanone

The new title compound (2E,6E)-2,6-bis(2,3-dimethoxybenzylidene)cyclohexanone (C 24 H 26 O 5,M r=394.45) has been synthesized,and its crystal structure was studied.The title compound crystallizes in the orthorhombic system,space group Pca2 1 with a=17.536(2),b=14.8515(16),c=8.0512(9),V=2096.8(4) 3,Z=4,D c=1.250 g/cm 3,λ=0.71073,μ=0.087 mm-1 and F(000)=840.The structure was solved by direct methods and refined to R=0.0533 and wR=0.1248 from 2727 observed reflections (I > 2σ(Ⅰ)).The title molecules are connected through hydrogen bonds to generate a 3-D supramolecule.The preliminary biological tests showed definitely biological activity for the title compound.     

Nickel Boride Catalysts in Organic Synthesis (IV). The Effect of Water Washing on P-2 Nickel Boride Catalyst

Water washing of P-2 nickel boride brings about a new catalyst designated as P-2W nickel boride. This P-2W catalyst is more reactive than P-1 or P-2 in the hydrogenation of cyclohexanone and nitrobenzene. The P-2W, however, is less selective than P-2 in the hydrogenation of cyclic olefins.     

Baeyer–Villiger oxidation of cyclohexanone by molecular oxygen with Fe–Sn–O mixed oxides as catalysts

Fe–Sn–O mixed oxides were synthesized and used as catalysts for Baeyer–Villiger oxidation of cyclohexanone, which showed both high catalytic activity and selectivity. X‐ray powder diffraction and scanning electron microscopy suggested that the Fe–Sn–O catalysts had a tetragonal structure with a grain size of 29.3 nm. An ε‐caprolactone yield as high as 98.8% was obtained in a small‐scale experiment (5 mmol of cyclohexanone). In a scale‐up test (20 mmol of cyclohexanone), the cyclohexanone conversion and ε‐caprolactone yield were 96.7 and 96.5%, respectively. In addition, the catalysts can be reused five times without any major decline in catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.     

Asymmetric cross-aldol reaction of isatin and ketones catalyzed by crude earthworm extract as efficient biocatalyst

ABSTRACT

The asymmetric cross-aldol reaction of simple ketones (acetone, cyclohexanone) with isatin derivatives in the presence of crude extract from earthworms as green and effective biocatalyst proceeds easily in MeCN/H₂O (1:1) as solvent to afford 3-hydroxy-2-oxindoles derivatives. Ten compounds were synthesized in high yields (62–88%) and moderate ee (29–42%). Structure of the synthesized compounds has been characterized on the basis of NMR spectra and CHN analysis. The ee of the obtained compounds was determined by chiral phase HPLC analysis.     

苯基磺酸官能化中孔硅基材料催化环己酮Aldol缩合反应

2-(1环-己烯基)环己酮是一种植物防腐杀菌剂,作为制备柑桔类水果的保鲜剂、分散染料染色的载体物质邻苯基苯酚(Ortho-phenylphenol,OPP)的原料而备受重视。其与环己叉基环己酮互为同分异构体,均由环己酮A ldol缩合反应合成,该过程是包括醇醛缩合、脱水在内的亲核加成-消除反应,     

Synthesis of hexa-, tetra-, and dihydroxanthene derivatives from salicylaldehyde aminals

Salicylaldehyde aminals react with cyclohexanone upon heating to form tetrahydroxanthene derivatives. The structure of one of these derivatives,viz., 5,7-dichloro-4a-morpholino-1,2,3,4-tetrahydro-4aH-xanthene, was established by X-ray diffraction analysis. The scheme of the reaction was suggested, which involves cycloaddition of intermediateo-methylenequinone (from aminal) and enamine (from cyclohexanone). The reactions of salicylaldehyde aminals with enamines that formed from cyclohexanone can successively afford derivatives of hexahydroxanthene, tetrahydroxanthene, and dihydroxanthene. Procedures were developed for the synthesis of these compounds.N-Substituted 4a-amino-7-nitro-1,2,3,4-tetrahydro-4aH-xanthenes were also prepared by the reactions of dialkylammonium 2-formyl-4-nitrophenoxides with the above-mentioned enamines. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 959–965, May, 1999.