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131.
132.
V. V. Prokopenko G. P. Okonnishnikova I. P. Klimenko E. V. Shulishov Yu. V. Tomilov 《Russian Chemical Bulletin》2007,56(8):1515-1521
Methyl 2-cyclopropyl-2-diazoacetate was synthesized from acetylcyclopropane in few chemical steps in ∼55% total yield. Its
copper or rhodium-catalyzed dediazoniation exclusively proceeds through the intramolecular isomerization of generated cyclopropyl(methoxycarbonyl)carbene
to 1-methoxycarbonylcyclobutene, irrespective of the presence or the absence of unsaturated compounds. However, in the presence
of acrylates or strained cycloalkenes, this diazo ester is being slowly involved into the 1,3-dipolar cycloaddition, giving
cyclopropyl-substituted pyrazolinecarboxylates, which in case of 1-pyrazolines easily lose nitrogen molecule to selectively
afford 1-cyclopropylcyclopropanecarboxylate derivatives.
Dedicated to Academician V. A. Tartakovsky in honor of his 75th anniversary.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1459–1465, August, 2007. 相似文献
133.
134.
Dzhemilev U. M. Ibragimov A. G. Khafizova L. O. Parfenova L. V. Yalalova D. F. Khalilov L. M. 《Russian Chemical Bulletin》2001,50(8):1465-1468
The reactions of 3-alkyl-1-ethylalumacyclopentanes with allyl halides in the presence of Ni(acac)2 as a catalyst were studied by dynamic NMR spectroscopy. Under the action of Ni complexes, alumacyclopentanes initially undergo intramolecular hydride transfer to give but-3-enyl(ethyl)aluminum hydrides and then react with the starting allyl halide, yielding but-3-enyl(ethyl)aluminum halides. Subsequent intramolecular carboalumination affords the corresponding 1,1-disubstituted cyclopropanes. 相似文献
135.
S. N. Lakeev F. Z. Galin L. M. Khalilov G. A. Tolstikov 《Russian Chemical Bulletin》1992,41(3):566-570
Some reactions of phthalimide-containing keto-stabilized sulfur ylides have been investigated. It was established that in addition to the formation of the usual products for keto-stabilized sulfur ylides, the reaction with acrylonitrile is accompanied by a rearrangement and leads to 1,1-disubstituted cyclopropanes.Institute of Chemistry, Bashkir Science Center, Urals Branch, Russian Academy of Sciences, 450054 Ufa. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 720–726, March, 1992. 相似文献
136.
Rh2(OAc)4‐Catalyzed decomposition of diazo esters in the presence of perfluoroalkyl‐ or perfluoroaryl‐substituted silyl enol ethers smoothly provided the corresponding alkyl 2‐siloxycyclopropanecarboxylates in very good yields. The generated donor? acceptor cyclopropanes are equivalents of γ‐oxo esters, which we demonstrated by their one‐pot transformations to yield fluorine‐containing heterocycles. A reductive procedure selectively afforded perfluoroalkyl‐substituted γ‐hydroxy esters or γ‐lactones. The treatment of the donor? acceptor cyclopropanes with hydrazine or phenylhydrazine afforded a series of perfluoroalkyl‐ and perfluoroaryl‐substituted 4,5‐dihydropyridazin‐3(2H)‐ones. 相似文献
137.
Charles Fehr Dr. Beat Winter Iris Magpantay 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(38):9773-9784
We describe in detail a direct, stereoselective synthesis of (?)‐cubebol based on a Pt‐, Au‐, or Cu‐catalyzed cycloisomerization in which control of the configuration of the propargylic center is essential for the facial selectivity. In addition, we show that cycloisomerization reactions of enantioenriched propargyl pivalates occur with substantial chirality transfer. We confirm a mechanism by means of cyclization followed by an [1,2]‐acyl migration for the Pt‐ and the Au‐catalyzed cycloisomerization. So far, no evidence supports that the Cu‐catalyzed cycloisomerization follows the same reaction course. 相似文献
138.
Jian‐Mei Lu Dr. Zhi‐Bin Zhu Min Shi Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(4):963-971
Lewis acid or Brønsted acid catalyzed reactions of vinylidene cyclopropanes (VDCPs), 1 , with activated carbon–nitrogen, nitrogen–nitrogen, and iodine–nitrogen double‐bond‐containing compounds have been thoroughly investigated. We found that pyrrolidine and 1,2,3,4‐tetrahydroquinoline derivatives can be formed in good yields in the reactions of VDCPs 1 with ethyl (arylimino)acetates 2 by a [3+2] cycloaddition or intramolecular Friedel–Crafts reaction pathway. Based on these results, we found that activated carbon–nitrogen and nitrogen–nitrogen double‐bond‐containing compounds, such as N‐toluene‐4‐sulfonyl (N‐Ts) imines 5 and diisopropylazodicarboxylate ( 7 ), can also react with VDCPs 1 to give [3+2] cycloaddition products in moderate to good yields in the presence of a Lewis acid. When N‐tert‐butoxycarbonyl aldimine 9 was used as the substrate, six‐membered cycloaddition products 10 and 11 were formed in moderate yields in the presence of a Brønsted acid, trifluoromethanesulfonic acid (TfOH). The reactions of VDCPs 1 with N‐Ts‐iminophenyliodinane ( 12 ) were also carried out in the presence of (CuOTf)2 ? C6H6 and it was found that nitrogen‐containing indene derivatives 13 were obtained, rather than the aziridination products. Plausible mechanisms for all of these transformations are discussed, based on the obtained results. 相似文献
139.
140.