排序方式: 共有76条查询结果,搜索用时 785 毫秒
21.
Satyajit Dey 《Tetrahedron letters》2005,46(33):5483-5486
The first synthesis of BE-23254, an unusual angucycline antibiotic, is reported. It involves regioselective condensation of naphthalenone 4 and chlorine-containing isobenzofuranone 16 as the key step. 相似文献
22.
Satyajit Saha 《Pramana》2001,57(1):149-159
In the coming decade, the expanding field of experimental nuclear physics in our country is going to see a quantum leap in
research and developmental activities with new accelerator facilities like the variable energy cyclotron with ECR heavy ion
source, the upcoming K-500 superconducting cyclotron, both at VECC, Calcutta, and the superconducting linac boosters at both
the Pelletron Accelerator Facilities at TIFR, Mumbai and NSC, New Delhi. When heavy ion beam available from such machines
fall on a target and undergo collision, very rich and often pristine fields of research open up. In order to carry on such
activities, we have taken up a project to build a multi element gamma, heavy ion and neutron array of detectors (MEGHNAD)
to detect and study the properties of a wide variety of particles like neutrons, protons, light mass clusters, massive ejected
fragments, and gamma rays with good solid angle coverage and efficiency. Design of the detector array, performance of the
prototype detector and brief outline of the research programme to be undertaken with the detector array will be discussed.
For MEGHNAD Project. 相似文献
23.
24.
Dendrimers: Nano Molecular‐Platform: A Protocol to Write Energy Transmission Program Inside a Molecule for Bio‐Inspired Supramolecular Engineering (Adv. Funct. Mater. 10/2014)
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Subrata Ghosh Mrinal Dutta Satyajit Sahu Daisuke Fujita Anirban Bandyopadhyay 《Advanced functional materials》2014,24(10):1338-1338
25.
Brønsted Acid‐Catalyzed,Highly Enantioselective Addition of Enamides to In Situ‐Generated ortho‐Quinone Methides: A Domino Approach to Complex Acetamidotetrahydroxanthenes
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Satyajit Saha Prof. Dr. Christoph Schneider 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(6):2348-2352
The highly enantioselective conjugate addition of enamides and enecarbamates to in situ‐generated ortho‐quinone methides, upon subsequent N,O‐acetalization, gives rise to acetamido‐substituted tetrahydroxanthenes with generally excellent enantio‐ and diastereoselectivities. A chiral BINOL‐based phosphoric acid catalyst controls the enantioselectivity of the carbon–carbon bond‐forming event. The products are readily converted into other xanthene‐based heterocycles. 相似文献
26.
27.
Dr. Sandip Kumar Das Dr. Satyajit Roy Prof. Dr. Buddhadeb Chattopadhyay 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202210912
Over the past few years, the development of efficient methods to construct high-valued N-heterocyclic molecules have received massive attention owing to their extensive application in the areas of medicinal chemistry, drug discovery, natural product synthesis and so on. To access those high-valued N-heterocycles, many methods have been developed. In this context, transition-metal-catalyzed denitrogenative annulation of 1,2,3-triazoles and 1,2,3,4-tetrazoles has appeared as a powerful synthetic tool because it offers a step- and atom-economical route for the preparation of the nitrogen-rich molecules. Compared with the denitrogenative annulation of various 1,2,3-triazole frameworks, annulation of 1,2,3,4-tetrazole remains more challenging due to the inertness of the tetrazole moiety. This Review summarizes the significant achievements made in the field of denitrogenative annulation of various 1,2,3-triazoles and 1,2,3,4-tetrazoles including some pioneering examples in this area of research. We anticipate that this denitrogenative annulation reaction will find broad applications in the pharmaceutical industry, drug discovery and other fields of medicinal chemistry. 相似文献
28.
Dr. Saibal Bera Dr. Satyajit Das Prof. Dr. Manuel Melle-Franco Prof. Dr. Aurelio Mateo-Alonso 《Angewandte Chemie (International ed. in English)》2023,62(5):e202216540
Organic cages have gained increasing attention in recent years as molecular hosts and porous materials. Among these, barrel-shaped cages or molecular nanobarrels are promising systems to encapsulate large hosts as they possess windows of the same size as their internal cavity. However, these systems have received little attention and remain practically unexplored despite their potential. Herein, we report the design and synthesis of a new trigonal prismatic organic nanobarrel with two large triangular windows with a diameter of 12.7 Å optimal for the encapsulation of C60. Remarkably, this organic nanobarrel shows a high affinity for C60 in solvents in which C60 is virtually insoluble, providing stable solutions of C60. 相似文献
29.
A series of pH-responsive random copolymers comprised of 2-hydroxyethyl methacrylate (HEMA) and tert-butyl carbamate (Boc)-protected phenylalanine methacryloyloxyethyl ester (Boc-Phe-EMA) were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization in N,N′-dimethylformamide (DMF) at 70 °C. The synthesized copolymers were comprehensively characterized using a combination of techniques, including 1H NMR, FT-IR spectroscopy and size exclusion chromatography (SEC). Reactivity of each monomers towards controlled radical polymerization was evaluated by determining the reactivity ratios by virtue of extended Kelen-Tüdös method at high conversions revealed the higher reactivity of non-modified HEMA (rHEMA=1.03) in contrast to Boc-Phe-EMA (rBoc-Phe-EMA=0.48). Furthermore, the expulsion of the Boc-groups resulted copolymers with ionizable pendant primary ammonium and hydroxyl groups. To understand the glass transition behaviours of homo- and co-polymers, differential scanning calorimetric (DSC) measurements were carried out. The effect of HEMA content on the pH-sensitivity of the copolymers in aqueous medium was investigated through turbidity measurements. Finally, the counteranion exchange from trifluoroacetate to chloride provided copolymers with enhanced water solubility and unaltered phase transition pH. 相似文献
30.
We present the next-to-leading order QCD corrections to the associated production of the vector gauge boson (Z/W±) and the graviton in the large extra dimension model at the LHC. We estimate the impact of the QCD corrections on the total cross sections as well as the differential distributions of the gauge bosons and find that they are significant. We also study the dependence of the cross sections on the arbitrary factorization scale and show the reduction in the scale uncertainties at NLO level. Further, we discuss the ultraviolet sensitivity of the theoretical predictions. 相似文献