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1.
Yu. I. Pyatnitskii P. E. Strizhak N. K. Lunev 《Theoretical and Experimental Chemistry》2009,45(5):325-330
A model is proposed for the kinetics of the direct conversion of synthesis gas to dimethyl ether (DME) on a bifunctional catalyst
in a flow reactor. Calculations for the yield of methanol and DME were carried out using literature data for the kinetics
of methanol synthesis and methanol dehydration. 相似文献
2.
β,γ‐Unsaturated ketones are an important class of organic molecules. Herein, copper catalysis has been developed for the synthesis of β‐γ‐unsaturated ketones through 1,2‐addition of α‐carbonyl iodides to alkynes. The reactions exhibit wide substrate scope and high functional group tolerance. The reaction products are versatile synthetic intermediates to complex small molecules. The method was applied for the formal synthesis of (±)‐trichostatin A, a histone deacetylase inhibitor. 相似文献
3.
An Improved Protocol for Synthesis of 3‐Substituted 5‐Arylidene‐2‐thiohydantoins: Two‐step Procedure Alternative to Classical Methods
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Olga Yu Kuznetsova Roman L. Antipin Anna V. Udina Olga O. Krasnovskaya Elena K. Beloglazkina Vladimir I. Terenin Victor E. Koteliansky Nikolay V. Zyk Alexander G. Majouga 《Journal of heterocyclic chemistry》2016,53(5):1570-1577
A novel method for the direct synthesis of 5‐arylidene‐2‐thiohydantoins from thioureas and aromatic aldehydes in the presence of base in ethanol was developed. Application of this efficient method allowed preparing thiohydantoins, which are difficult to synthesis by traditional methods. 相似文献
4.
A General Entry to Antifeedant Sesterterpenoids: Total Synthesis of (+)‐Norleucosceptroid A, (−)‐Norleucosceptroid B,and (−)‐Leucosceptroid K
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M. Sc. Cedric L. Hugelshofer Dr. Thomas Magauer 《Angewandte Chemie (International ed. in English)》2014,53(42):11351-11355
The first asymmetric total synthesis of the antifeedant terpenoids (+)‐norleucosceptroid A, (?)‐norleucosceptroid B, and (?)‐leucosceptroid K has been accomplished. This highly concise synthetic route was guided by our efforts to develop a platform for the collective synthesis of a whole family of antifeedant natural products. The synthesis features a Hauser–Kraus‐type annulation followed by an unprecedented, highly efficient intramolecular dilactol aldol‐type condensation reaction to produce the 5,6,5 skeleton. The developed synthetic route proceeds for norleucosceptroid A and B in 16 steps (longest linear sequence) from known compounds. 相似文献
5.
Cedric L. Hugelshofer Thomas Magauer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(42):11533-11537
The first asymmetric total synthesis of the antifeedant terpenoids (+)‐norleucosceptroid A, (−)‐norleucosceptroid B, and (−)‐leucosceptroid K has been accomplished. This highly concise synthetic route was guided by our efforts to develop a platform for the collective synthesis of a whole family of antifeedant natural products. The synthesis features a Hauser–Kraus‐type annulation followed by an unprecedented, highly efficient intramolecular dilactol aldol‐type condensation reaction to produce the 5,6,5 skeleton. The developed synthetic route proceeds for norleucosceptroid A and B in 16 steps (longest linear sequence) from known compounds. 相似文献
6.
A simple and convenient one-pot synthesis route is described for the synthesis of 3,5-diaryl-1H-pyrazoles in short reaction times from the reaction of α-epoxyketones with semicarbazide hydrochloride under mild conditions.
Correspondence: Farzad Nikpour, Department of Chemistry, Faculty of Sciences, University of Kurdistan, P.O. Box 66315-416,
Sanandaj, Iran. 相似文献
7.
Xianwei Sun Prof. Dr. Zhenlei Song Hongze Li Changzheng Sun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(51):17589-17594
A [1,4]‐S‐ to O‐silyl migration has been exploited to chemoselectively transform esters into ketones by using organolithium reagents, allowing multicomponent synthesis of α‐thioketones. Mechanistic studies reveal that this migration proceeds in an intramolecular manner and is more favorable than the corresponding [1,5]‐S‐ to O‐ and [1,3]‐C‐ to O‐silyl migrations. The resulting α‐thioketones are valuable building blocks for the synthesis of cyclic or multifunctionalized organosulfur compounds. 相似文献
8.
A new route towards the synthesis of N‐substituted‐4‐formylpiperidine using N‐benzyl or tryptaminyl‐sulfonylacetamide and α,β‐unsaturated ester as starting materials is described. Formal synthesis of Aricept®, deethylibophyllidine, and isoguvacine, which have potential biological activities, were synthesized via this strategy. 相似文献
9.
Heteroannulation of Arynes with α‐Amino Imides: Synthesis of 2,2‐Disubstituted Indolin‐3‐ones and Application to the Enantioselective Total Synthesis of (+)‐Hinckdentine A
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Dr. Rubén O. Torres‐Ochoa Dr. Thomas Buyck Dr. Qian Wang Prof. Dr. Jieping Zhu 《Angewandte Chemie (International ed. in English)》2018,57(20):5679-5683
A novel heteroannulation reaction between α‐amino imides and in situ generated arynes has been developed for the synthesis of 2,2‐disubstituted indolin‐3‐ones. An enantioselective total synthesis of the marine alkaloid (+)‐hinckdentine A was subsequently accomplished using this reaction as a key step. A catalytic enantioselective Michael addition of an α‐aryl‐α‐isocyanoacetate to phenyl vinyl selenone was employed for the construction of the enantioenriched α‐quaternary α‐amino ester. 相似文献
10.
Debendra K. Mohapatra Dr. Pragna P. Das Manas Ranjan Pattanayak J. S. Yadav Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(7):2072-2078
A novel iodine‐catalyzed highly diastereoselective synthesis of trans‐2,6‐disubstituted‐3,4‐dihydropyrans have been achieved from δ‐hydroxy α,β‐unsaturated aldehydes by treating with allyltrimethyl silane in THF at room temperature with good to excellent yields. This methodology has been successfully implemented for a concise asymmetric synthesis of C28–C37 dioxabicyclo[3.2.1]octane ring system of (+)‐sorangicin A in 8 steps with 21 % overall yield. 相似文献
11.
Palladium‐Catalyzed Intramolecular Trost–Oppolzer‐Type Alder–Ene Reaction of Dienyl Acetates to Cyclopentadienes
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Siddheshwar K. Bankar Bara Singh Pinku Tung Prof. Dr. S. S. V. Ramasastry 《Angewandte Chemie (International ed. in English)》2018,57(6):1678-1682
A new approach to the synthesis of highly substituted cyclopentadienes, indenes, and cyclopentene‐fused heteroarenes by means of the Pd‐catalyzed Trost–Oppolzer‐type intramolecular Alder–ene reaction of 2,4‐pentadienyl acetates is described. This unprecedented transformation combines the electrophilic features of the Tsuji–Trost reaction with the nucleophilic features of the Alder–ene reaction. The overall outcome can be perceived as a hitherto unknown “acid‐free” iso‐Nazarov‐type cyclization. The versatility of this strategy was further demonstrated by the formal synthesis of paucifloral F, a resveratrol‐based natural product. 相似文献
12.
Yu‐Feng Liu Dan‐Dan Zhai Xiang‐Yu Zhang Prof. Dr. Bing‐Tao Guan 《Angewandte Chemie (International ed. in English)》2018,57(27):8245-8249
Direct functionalization of the benzylic C?H bond of diarylmethanes is an important strategy for the synthesis of diarylmethine‐containing compounds. However, the methods developed to date for this purpose require a stoichiometric amount (usually more) of either a strong base or an oxidant. Reported here is the first catalytic benzylic C?H bond addition of diarylmethanes to styrenes and conjugated dienes. A potassium zincate complex, generated from potassium benzyl and zinc amide, acts as a catalyst and displays good activity and chemoselectivity. Considering the atom economy of the reaction and the ready availability of the catalyst, this reaction constitutes a practical, efficient method for diarylalkane synthesis. 相似文献
13.
Prof. Dr. Li‐Jun Gu Cheng Jin Hong‐Tao Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(24):8741-8744
A novel nickel N‐heterocyclic carbene catalyzed cross‐coupling reaction of aryl aldehydes with boronic esters for the synthesis of aryl ketones was developed. This reaction provides a mild, practical method toward aryl ketones, which are versatile intermediates and building blocks in organic synthesis. 相似文献
14.
Mechanochemical Strecker Reaction: Access to α‐Aminonitriles and Tetrahydroisoquinolines under Ball‐Milling Conditions
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Dr. José G. Hernández Mathias Turberg Dr. Ingo Schiffers Prof. Dr. Carsten Bolm 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(41):14513-14517
A mechanochemical version of the Strecker reaction for the synthesis of α‐aminonitriles was developed. The milling of aldehydes, amines, and potassium cyanide in the presence of SiO2 gave the corresponding α‐aminonitriles in good to high yields. The high efficiency of the mechanochemical Strecker‐type multicomponent reaction allowed the one‐pot synthesis of tetrahydroisoquinolines after a subsequent internal N‐alkylation reaction. 相似文献
15.
Chepuri V. Suneel Kumar Dr. Vedavati G Puranik Dr. Chepuri V. Ramana 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(31):9601-9611
A strategy directed towards the total synthesis of isatisine A that involves several late‐stage metal‐catalyzed transformations that address the key carbon–carbon and carbon–heteroatom bond formations has been developed. As a part of this strategy, methods for the addition of indoles to isatogens that lead selectively to either 2,2‐disubstituted N‐hydroxyindolin‐3‐one or 2,2‐disubstituted indolin‐3‐one compounds have been developed by employing InCl3 as a catalyst or as the reagent. The present methods provide the first examples of the additions of indoles to the isatogen nucleus. To demonstrate its viability, the synthesis of 13‐deoxy‐isatisine A has been completed in ten steps from a known and easily available lactone. 相似文献
16.
Marc Montesinos‐Magraner Matteo Costantini Rodrigo Ramírez‐Contreras Michael E. Muratore Magnus J. Johansson Abraham Mendoza 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(18):5991-5996
Asymmetric cyclopropane synthesis currently requires bespoke strategies, methods, substrates, and reagents, even when targeting similar compounds. This approach slows down discovery and limits available chemical space. Introduced herein is a practical and versatile diazocompound and its performance in the first unified asymmetric synthesis of functionalized cyclopropanes. The redox‐active leaving group in this reagent enhances the reactivity and selectivity of geminal carbene transfer. This effect allowed the asymmetric cyclopropanation of various olefins, including unfunctionalized aliphatic alkenes, that enables the three‐step total synthesis of (?)‐dictyopterene A. This unified synthetic approach delivers high enantioselectivities that are independent of the stereoelectronic properties of the functional groups transferred. Our results demonstrate that orthogonally differentiated diazocompounds are viable and advantageous equivalents of single‐carbon chirons. 相似文献
17.
Asymmetric Ruthenium‐Catalyzed Hydrogenation of 2,6‐Disubstituted 1,5‐Naphthyridines: Access to Chiral 1,5‐Diaza‐cis‐Decalins
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Jianwei Zhang Fei Chen Yan‐Mei He Prof. Dr. Qing‐Hua Fan 《Angewandte Chemie (International ed. in English)》2015,54(15):4622-4625
The first asymmetric hydrogenation (AH) of 2,6‐disubstituted and 2,3,6‐trisubstituted 1,5‐naphthyridines, catalyzed by chiral cationic ruthenium diamine complexes, has been developed. A wide range of 1,5‐naphthyridine derivatives were efficiently hydrogenated to give 1,2,3,4‐tetrahydro‐1,5‐naphthyridines with up to 99 % ee and full conversions. This facile and green protocol is applicable to the scaled‐up synthesis of optically pure 1,5‐diaza‐cis‐decalins, which have been used as rigid chelating diamine ligands for asymmetric synthesis. 相似文献
18.
Visible‐Light‐Induced CS Bond Activation: Facile Access to 1,4‐Diketones from β‐Ketosulfones
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Jun Xuan Zhu‐Jia Feng Prof. Dr. Jia‐Rong Chen Dr. Liang‐Qiu Lu Prof. Dr. Wen‐Jing Xiao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(11):3045-3049
A novel method for the synthesis of 1,4‐diketones from β‐ketosulfones was developed by means of a visible light‐induced C?S bond activation process. Symmetrical and unsymmetrical 1,4‐diketones can be easily prepared in moderate to good yields. 相似文献
19.
Srikanth Annareddygari Venkateshwer Reddy Kasireddy Jayachandra Reddy 《Journal of heterocyclic chemistry》2019,56(12):3267-3276
A new and efficient method for the synthesis of various aza‐fused poly‐hetero aromatics has been described. This protocol includes an intermolecular condensation followed by metal‐free base‐promoted intramolecular C―N coupling reaction. The advantage of this one‐pot transformation lies in the use of simple cyclic amidines‐like compounds without prefunctionalization of the starting heterocycles. 相似文献
20.
Palladium‐Catalyzed Enantioselective Reductive Heck Reactions: Convenient Access to 3,3‐Disubstituted 2,3‐Dihydrobenzofuran
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Zhan‐Ming Zhang Bing Xu Yanyan Qian Lizuo Wu Yuanqi Wu Lujia Zhou Prof. Dr. Yu Liu Prof. Dr. Junliang Zhang 《Angewandte Chemie (International ed. in English)》2018,57(32):10373-10377
The first example of highly enantioselective intramolecular hydroarylation of allyl aryl ethers was realized by palladium‐catalyzed reductive heck reactions utilizing a new chiral sulfinamide phosphine ligand (N‐Me‐ XuPhos ). N‐Me‐ XuPhos can be easily prepared on gram scale from readily available starting materials in a one‐pot synthesis approach. A series of optically active 2,3‐dihydrobenzofurans bearing a quaternary stereocenter were obtained in good yields and with excellent enantioselectivities. The practicality of this reaction was validated in the straightforward synthesis of CB2 receptor agonists. Moreover, deuterium was efficiently incorporated into the products. 相似文献