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161.
4,5-Diaryl-Δ4-imidazolin-2-ones undergo conversion to 2,2-dialkoxy-4,5-diaryl-Δ4-imidazolines by a characteristic solvent interaction of the carbonyl group on irradiation in alcoholic solvents. The photochemical
oxidative cyclization of the stilbene system in these compounds to the corresponding phenanthrene derivatives does not occur
under the usual conditions. Acidic conditions hinder the ketal formation of the carbonyl group and favour the oxidative dehydrocyclization
reaction to the phenanthrene derivatives. These reactions have been found to be general to the 4,5-diaryl-Δ4-imidazolin-2-ones and plausible mechanistic pathways have been suggested for the two different selective reactions. 相似文献
162.
The title compounds(Z)-3-(2-(3-chloropyridin-2-yl)hydrazono)indolin-2-one(A) and 7-bromo-(Z)-3-((4-pyridinyl)carboxlichydrazono)-2-indolinone(B) have been synthesized and structurally determined by elemental analysis and single-crystal X-ray diffraction studies.Compound A(C13H8ClN4O) belongs to the orthorhombic crystal system,space group Pca21 with a = 20.799(4),b = 4.9312(10),c = 11.764(2),V = 1206.6(4)3,Mr = 271.68,Dc = 1.496 g/cm3,μ = 0.313 mm-1,F(000) = 556,Z = 4,the final R = 0.0346 and wR = 0.0831 for 2683 observed reflections with I > 2σ(I).Compound B(C14H9BrN4O2) belongs to the triclinic crystal system,space group P1 with a = 6.6834(13),b = 7.0727(14),c = 14.285(3),α = 95.56(3),β = 99.00(3),γ = 102.95(3)°,V = 643.8(2)3,Mr = 345.16,Dc = 1.780 g/cm3,μ = 3.203 mm-1,F(000) = 344,Z = 2,the final R = 0.0487 and wR = 0.1167 for 2334 observed reflections with I > 2σ(I).The preliminary herbicidal bioassay reveals that compounds A and B have some inhibition both in vivo and in vitro against AHAS. 相似文献
163.
Novel caged intramolecular ketals of β‐C‐glycosidic ketones were prepared from pyranoses. The structures of the new compounds were elucidated by NMR and HRMS spectral analysis. Preliminary studies revealed that the intramolecular ketal could be used to protect 3‐ and 6‐hydroxyl groups of β‐C‐glycosidic ketones. 相似文献
164.
Because of its various biological activities, isatin plays important roles in organic chemistry. The C-3 carbonyl group of the isatin possesses very high reactivity and thus isatin possesses many diverse applications in organic synthesis. This carbonyl group reacts like a prochiral center. For the organic synthetic chemist, the conception of a spiroheterocyclic building block has always been interesting, as it often requires synthetic design based on specific strategies. This review summarizes the synthesis of various multispiro heterocyclic compounds by using isatin through 1,3-dipolar cycloaddition reactions and multicomponent reactions. 相似文献
165.
Novel 2,2‐bis‐C‐functionalized chain glucosid‐3‐uloses have been synthesized in the form of ketal. The synthesis is rather convenient through one pot multistep reactions and no expensive reagents are involved. The products are formed via autoxidation‐Michael addition mechanism and their structures were characterized by X‐ray crystallographic analysis. Their crystal stuctures are stablilized by intermolecular hydrogen bonds and double‐strand supramolecular stacking is observed. 相似文献
166.
Mojtaba Mirhosseini Moghaddam Ayoob Bazgir Akhondi Mohammad Mehdi Ramin Ghahremanzadeh 《中国化学》2012,30(3):709-714
The combination of isatin, barbituric acid, and cyclohexane‐1,3‐dione derivatives in the presence of alum (KAl(SO4)2·12H2O) as a catalyst for 15 min was found to be a suitable and efficient method for the synthesis of spiro[chromeno[2,3‐d]pyrimidine‐5,3′‐indoline]‐tetraones. 相似文献
167.
Carolyn Selenski 《Tetrahedron》2006,62(22):5298-5307
We report the synthesis of diinsininone (33), the aglycone of (±)-diinsinin (2). Thereby, we complete the first construction of a proanthocyanidin (PA) type-A compound incorporating a [3.3.1]-bicyclic ketal as its characteristic core. Our strategy utilizes a coupling between a benzopyrilium salt and a flavanone that proves applicable to other PA type-A compounds. During this undertaking, treatment of naringenin (9) with 2-iodoxybenzoic acid (IBX) followed by reductive work-up affords eriodictyol (10). This reactivity mirrors that of catechol hydroxylase (F3H) found in the flavonoid pathway. Other interesting transformations include the formation of flavonoids through an ortho-quinone methide (o-QM) cycloaddition-oxidation sequence and regioselective β-glycosidations of several unprotected flavanones suggesting a likely synthesis of 2 from the aglycone 33. 相似文献
168.
SONAWANE Atul E. PAWAR Yogesh A. NAGLE Pramod S. MAHULIKAR Pramod P. MORE Dhananjay H. 《中国化学》2009,27(10):2049-2054
A series of novel 3‐methyl‐N"‐(2‐oxoindolin‐3‐ylidene)‐4H‐benzo[b][1,4]thiazine‐2‐carbohyrazides have been synthesized and studied on their in vitro antimicrobial activity potency to establish structure‐activity relationship. Several compounds demonstrated promising antifungal and antibacterial activity; however, other tested compounds exhibited moderate to poor antimicrobial activity with respect to the reference drug against the test strains. 相似文献