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101.
Ye Wang 《Research on Chemical Intermediates》2006,32(3):235-251
Recent studies on iron-based heterogeneous catalysts for selective oxidation of hydrocarbons are reviewed with emphasis on
the partial oxidation of methane and the epoxidation of alkenes. High dispersion of iron sites is essentially important for
the selective oxidations. The effective catalysts include immobilized or encapsulated iron complexes, iron-doped metal oxides
such as Fe3+-doped silica, iron-containing microporous and mesoporous materials, and iron-containing compounds with isolated iron sites
typified by iron phosphate. The structure-reactivity relationships and the factors affecting the catalytic performances are
discussed with the aim to uncover the requirements of the active iron sites in target-selective oxidation. 相似文献
102.
Joanne F. Kinneary Therese M. Roy Jeffrey S. Albert Heungsik Yoon Thomas R. Wagler Lucy Shen Cynthia J. Burrows 《Journal of inclusion phenomena and macrocyclic chemistry》1989,7(2):155-168
New nickel catalysts have been developed for the oxidation of alkenes to epoxides, alcohols, aldehydes and ketones. Mechanistic studies indicate that the oxidation reactions are very sensitive to the nature of the catalyst; only certain ligands including salen and the macrocycles cyclam and dioxocyclam render Ni(II) effective as a catalyst. A Ni(III) or Ni(IV)-oxo species has been postulated as the catalytically active oxidant which leads to oxygen atom transfer to alkenes in a stepwise process. Both iodosylbenzene and hypochlorite have been used as terminal oxidants; both systems give high yields of epoxidation of alkenes and varying amounts of C=C bond cleavage products. In order to reach an ultimate goal of hydrocarbon oxidation within a molecular recognition system, new molecular receptors for organic substrates have been investigated. The receptors are constructed from two subunits of cholic acid and display amphophilic character — a hydrophobic exterior and a hydrophilic interior. Conformational properties in the presence of polar guests in CDCl3 are described. 相似文献
103.
Maire P Breher F Grützmacher H 《Angewandte Chemie (International ed. in English)》2005,44(39):6325-6329
104.
105.
We have developed a simple and practical process for the oxidation of aromatic alkene to the corresponding carbonyl compounds using NaNO2 as an oxidant. The practical utility of this oxidative process has been demonstrated in the gram-scale oxidation of 1-(tert-butyl)-4-vinylbenzene. 相似文献
106.
Rachel E. M. Brooner Dr. Timothy J. Brown Prof. Ross A. Widenhoefer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(25):8276-8284
Cationic, two‐coordinate triphenylphosphine–gold(I)–π complexes of the form [(PPh3)Au(π ligand)]+ SbF6? (π ligand=4‐methylstyrene, 1? SbF6), 2‐methyl‐2‐butene ( 3? SbF6), 3‐hexyne ( 6? SbF6), 1,3‐cyclohexadiene ( 7? SbF6), 3‐methyl‐1,2‐butadiene ( 8? SbF6), and 1,7‐diphenyl‐3,4‐heptadiene ( 10? SbF6) were generated in situ from reaction of [(PPh3)AuCl], AgSbF6, and π ligand at ?78 °C and were characterized by low‐temperature, multinuclear NMR spectroscopy without isolation. The π ligands of these complexes were both weakly bound and kinetically labile and underwent facile intermolecular exchange with free ligand (ΔG≠≈9 kcal mol?1 in the case of 6? SbF6) and competitive displacement by weak σ donors, such as trifluoromethane sulfonate. Triphenylphosphine–gold(I)–π complexes were thermally unstable and decomposed above ?20 °C to form the bis(triphenylphosphine) gold cation [(PPh3)2Au]+SbF6? ( 2? SbF6). 相似文献
107.
Rachel E. M. Brooner Prof. Ross A. Widenhoefer 《Angewandte Chemie (International ed. in English)》2013,52(45):11714-11724
Cationic, two‐coordinate gold π complexes that contain a phosphine or N‐heterocyclic supporting ligand have attracted considerable attention recently owing to the potential relevance of these species as intermediates in the gold‐catalyzed functionalization of C? C multiple bonds. Although neutral two‐coordinate gold π complexes have been known for over 40 years, examples of the cationic two‐coordinate gold(I) π complexes germane to catalysis remained undocumented prior to 2006. This situation has changed dramatically in recent years and well‐defined examples of two‐coordinate, cationic gold π complexes containing alkene, alkyne, diene, allene, and enol ether ligands have been documented. This Minireview highlights this recent work with a focus on the structure, bonding, and ligand exchange behavior of these complexes. 相似文献
108.
Lucas J. Oxtoby Zi‐Qi Li Van T. Tran Tue G. Erbay Ruohan Deng Peng Liu Keary M. Engle 《Angewandte Chemie (International ed. in English)》2020,59(23):8885-8890
Metal‐coordinating directing groups have seen extensive use in the field of transition‐metal‐catalyzed alkene functionalization; however, their waste‐generating installation and removal steps limit the efficiency and practicality of reactions that rely on their use. Inspired by developments in asymmetric organocatalysis, where reactions rely on reversible covalent interactions between an organic substrate and a chiral mediator, we have developed a transient‐directing‐group approach to reductive Heck hydroarylation of alkenyl benzaldehyde substrates that proceeds under mild conditions. Highly stereoselective migratory insertion is facilitated by in situ formation of an imine from catalytic amounts of a commercially available amino acid additive. Computational studies reveal an unusual mode of enantioinduction by the remote chiral center in the transient directing group. 相似文献
109.
(N‐Phosphinoamidinate)cobalt‐Catalyzed Hydroboration: Alkene Isomerization Affords Terminal Selectivity 下载免费PDF全文
Adam J. Ruddy Dr. Orson L. Sydora Dr. Brooke L. Small Prof. Dr. Mark Stradiotto Prof. Dr. Laura Turculet 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(43):13918-13922
Herein we establish the utility of a three‐coordinate (N‐phosphinoamidinate)cobalt(amido) pre‐catalyst that is capable of effecting challenging alkene isomerization/hydroboration processes at room temperature, leading to the selective terminal addition of the boron group. 相似文献
110.