全文获取类型
收费全文 | 425篇 |
免费 | 68篇 |
国内免费 | 15篇 |
专业分类
化学 | 499篇 |
晶体学 | 3篇 |
综合类 | 2篇 |
物理学 | 4篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 3篇 |
2020年 | 29篇 |
2019年 | 17篇 |
2018年 | 20篇 |
2017年 | 16篇 |
2016年 | 27篇 |
2015年 | 24篇 |
2014年 | 42篇 |
2013年 | 46篇 |
2012年 | 33篇 |
2011年 | 25篇 |
2010年 | 22篇 |
2009年 | 31篇 |
2008年 | 24篇 |
2007年 | 35篇 |
2006年 | 25篇 |
2005年 | 10篇 |
2004年 | 25篇 |
2003年 | 19篇 |
2002年 | 1篇 |
2001年 | 6篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1989年 | 1篇 |
排序方式: 共有508条查询结果,搜索用时 786 毫秒
91.
92.
Christian P. R. Hackenberger Dr. Dirk Schwarzer Dr. 《Angewandte Chemie (International ed. in English)》2008,47(52):10030-10074
The investigation of biological processes by chemical methods, commonly referred to as chemical biology, often requires chemical access to biologically relevant macromolecules such as peptides and proteins. Building upon solid‐phase peptide synthesis, investigations have focused on the development of chemoselective ligation and modification strategies to link synthetic peptides or other functional units to larger synthetic and biologically relevant macromolecules. This Review summarizes recent developments in the field of chemoselective ligation and modification strategies and illustrates their application, with examples ranging from the total synthesis of proteins to the semisynthesis of naturally modified proteins. 相似文献
93.
Daniel Moser Dr. Kalipada Jana Prof. Dr. Christof Sparr 《Angewandte Chemie (International ed. in English)》2023,62(39):e202309053
Herein, we describe the feasibility of atroposelective PIII/PV=O redox organocatalysis by the Staudinger–aza-Wittig reaction. The formation of isoquinoline heterocycles thereby enables the synthesis of a broad range of valuable atropisomers under mild conditions with enantioselectivities of up to 98 : 2 e.r. Readily prepared azido cinnamate substrates convert in high yield with stereocontrol by a chiral phosphine catalyst, which is regenerated using a silane reductant under Brønsted acid co-catalysis. The reaction provides access to diversified aryl isoquinolines, as well as benzoisoquinoline and naphthyridine atropisomers. The products are expeditiously transformed into N-oxides, naphthol and triaryl phosphine variants of prevalent catalysts and ligands. With dinitrogen release and aromatization as ideal driving forces, it is anticipated that atroposelective redox organocatalysis provides access to a multitude of aromatic heterocycles with precise control over their configuration. 相似文献
94.
Wojtczak BA Andrysiak A Grüner B Lesnikowski ZJ 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(34):10675-10682
A general approach to the synthesis of nucleoside conjugates containing carborane and metallocarborane complexes, based on Huisgen 1,3-dipolar cycloaddition ("chemical ligation"), is described. Boron-cluster-donors bearing terminal azide or ethynyl groups were prepared in the ring-opening reaction of dioxane-boron-cluster adducts and an azide anion or suitable alkynol-derived alcoholate nucleophile. Analogous derivatives bearing terminal sulfhydryl groups were also prepared. Nucleosides with various spacers containing terminal azide or ethynyl groups, located within nucleobases or sugar residues, were used as boron-cluster acceptors. The proposed methodology provides a convenient way to synthesize libraries of boron-cluster-modified nucleosides for various applications. 相似文献
95.
Dr. Andrew R. Thomson Prof. Dr. Derek N. Woolfson 《Angewandte Chemie (International ed. in English)》2016,55(3):987-991
An ability to control the assembly of peptide nanotubes (PNTs) would provide biomaterials for applications in nanotechnology and synthetic biology. Recently, we presented a modular design for PNTs using α‐helical barrels with tunable internal cavities as building blocks. These first‐generation designs thicken beyond single PNTs. Herein we describe strategies for controlling this lateral association, and also for the longitudinal assembly. We show that PNT thickening is pH sensitive, and can be reversed under acidic conditions. Based on this, repulsive charge interactions are engineered into the building blocks leading to the assembly of single PNTs at neutral pH. The building blocks are modified further to produce covalently linked PNTs via native chemical ligation, rendering ca. 100 nm‐long nanotubes. Finally, we show that small molecules can be sequestered within the interior lumens of single PNTs. 相似文献
96.
Efficient Palladium‐Assisted One‐Pot Deprotection of (Acetamidomethyl)Cysteine Following Native Chemical Ligation and/or Desulfurization To Expedite Chemical Protein Synthesis
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Suman Kumar Maity Muhammad Jbara Shay Laps Prof. Ashraf Brik 《Angewandte Chemie (International ed. in English)》2016,55(28):8108-8112
The acetamidomethyl (Acm) moiety is a widely used cysteine protecting group for the chemical synthesis and semisynthesis of peptide and proteins. However, its removal is not straightforward and requires harsh reaction conditions and additional purification steps before and after the removal step, which extends the synthetic process and reduces the overall yield. To overcome these shortcomings, a method for rapid and efficient Acm removal using PdII complexes in aqueous medium is reported. We show, for the first time, the assembly of three peptide fragments in a one‐pot fashion by native chemical ligation where the Acm moiety was used to protect the N‐terminal Cys of the middle fragment. Importantly, an efficient synthesis of the ubiquitin‐like protein UBL‐5, which contains two native Cys residues, was accomplished through the one‐pot operation of three key steps, namely ligation, desulfurization, and Acm deprotection, highlighting the great utility of the new approach in protein synthesis. 相似文献
97.
98.
Simplest Monodentate Imidazole Stabilization of the oxy‐Tyrosinase Cu2O2 Core: Phenolate Hydroxylation through a CuIII Intermediate
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Linus Chiang William Keown Dr. Cooper Citek Dr. Erik C. Wasinger Prof. T. Daniel P. Stack 《Angewandte Chemie (International ed. in English)》2016,55(35):10453-10457
Tyrosinases are ubiquitous binuclear copper enzymes that oxygenate to CuII2O2 cores bonded by three histidine Nτ‐imidazoles per Cu center. Synthetic monodentate imidazole‐bonded CuII2O2 species self‐assemble in a near quantitative manner at ?125 °C, but Nπ‐ligation has been required. Herein, we disclose the syntheses and reactivity of three Nτ‐imidazole bonded CuII2O2 species at solution temperatures of ?145 °C, which was achieved using a eutectic mixture of THF and 2‐MeTHF. The addition of anionic phenolates affords a CuIII2O2 species, where the bonded phenolates hydroxylate to catecholates in high yields. Similar CuIII2O2 intermediates are not observed using Nπ‐bonded CuII2O2 species, hinting that Nτ‐imidazole ligation, conserved in all characterized Ty, has functional advantage beyond active‐site flexibility. Substrate accessibility to the oxygenated Cu2O2 core and stabilization of a high oxidation state of the copper centers are suggested from these minimalistic models. 相似文献
99.
100.