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1.
Xi‐Jie Dai Oliver D. Engl Thierry Len Stephen L. Buchwald 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(11):3445-3449
Herein, we report a practical two‐step synthetic route to α‐arylpyrrolidines through Suzuki–Miyaura cross‐coupling and enantioselective copper‐catalyzed intramolecular hydroamination reactions. The excellent stereoselectivity and broad scope for the transformation of substrates with pharmaceutically relevant heteroarenes render this method a practical and versatile approach for pyrrolidine synthesis. Additionally, this intramolecular hydroamination strategy facilitates the asymmetric synthesis of tetrahydroisoquinolines and medium‐ring dibenzo‐fused nitrogen heterocycles. 相似文献
2.
Eligeti Rajanarendar Baireddy Kishore Saini Ramakrishna 《Journal of heterocyclic chemistry》2015,52(6):1897-1901
An efficient CAN‐catalyzed synthesis of isoxazolyl spiro[indoline‐3,2′‐pyrrolidine]‐2,4′‐diones has been developed via one‐pot three‐component reaction of isoxazole amine, differently substituted isatins, and acetone at room temperature. Several catalysts and solvents have been screened for the efficiency, but the optimum results were obtained with CAN in THF. 相似文献
3.
An atom economic and facile synthesis of novel dispiro–oxindole–pyrrolidines has been achieved via a three‐component tandem cycloaddition of azomethine ylide generated in situ from isatin and sarcosine by decarboxylative condensation with N‐aryl‐3‐benzylidene‐pyrrolidine‐2,5‐dione derivatives as dipolarophiles. The salient features of synthetic procedure are characterized by the mild reaction conditions, high yields, high regioselectivity and stereoselectivity, one‐pot procedure, and operational simplicity. This regioselectivity was assumed to be under the influence of π–π stacking interactions between the aromatic rings of azomethine ylide and N‐aryl‐3‐benzylidene‐pyrrolidine‐2,5‐diones that further control the exo–endo selectivity of the reaction 1,3‐dipolar cycloaddition. The regiochemistry and structures of the cycloadducts were determined with spectroscopic data. 相似文献
4.
Pharmacokinetic study of dendrobine in rat plasma by ultra‐performance liquid chromatography tandem mass spectrometry 下载免费PDF全文
Shuanghu Wang Haiya Wu Peiwu Geng Yingying Lin Zezheng Liu Lijing Zhang Jianshe Ma Yunfang Zhou Xianqin Wang Congcong Wen 《Biomedical chromatography : BMC》2016,30(7):1145-1149
Dendrobine, considered as the major active alkaloid compound, has been used for the quality control and discrimination of Dendrobium which is documented in the Chinese Pharmacopoeia. In this work, a sensitive and simple ultra‐performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS) method for determination of dendrobine in rat plasma is developed. After addition of caulophyline as an internal standard (IS), protein precipitation by acetonitrile–methanol (9:1, v/v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 (2.1 ×100 mm, 1.7 µm) column with acetonitrile and 0.1% formic acid as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reaction monitoring mode was used for quantification using target fragment ions m/z 264.2 → 70.0 for dendrobine and m/z 205.1 → 58.0 for IS. Calibration plots were linear throughout the range 2–1000 ng/mL for dendrobine in rat plasma. The RSDs of intra‐day and inter‐day precision were both <13%. The accuracy of the method was between 95.4 and 103.9%. The method was successfully applied to pharmacokinetic study of dendrobine after intravenous administration. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
5.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(12):3216-3219
Siloxane bonds are usually synthesized by condensation reactions, such as hydrolysis/dehydration and cross‐coupling reactions, in which the generation of by‐products during bond formation can not be avoided. We have developed a one‐pot sequence of iridium‐catalyzed silyl ester hydrosilylation and boron‐catalyzed rearrangement of the resulting disilyl acetals for the construction of siloxane bonds, in principle without the formation of any by‐products. Moreover, the programmed synthesis of tri‐, tetra‐, and pentasiloxanes was possible in a single flask by combining the above sequence of iridium‐catalyzed hydrosilylation and boron‐catalyzed rearrangement with a boron‐catalyzed cross‐coupling reaction. The obtained oligosiloxanes are difficult to synthesize selectively by other known synthetic procedures. 相似文献
6.
Barry M. Trost Zhiwei Jiao Chao‐I. Hung 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(42):15298-15302
A general method for asymmetric synthesis of heteroaryl‐containing cycles via palladium‐catalyzed cyclization is reported. Most classes of nitrogen‐containing aromatics, including pyridines, quinolines, pyrimidines, various azoles and the derivatives of nucleobases are compatible substrates, offering various heteroaryl‐substituted cyclopentane, pyrrolidine, furanidine and bicyclo[4.3.1]decadiene derivatives with good to excellent enantioselectivity and diastereoselectivity. 相似文献
7.
《Journal of heterocyclic chemistry》2017,54(2):859-863
A new class of spiro compounds as dispiro[indoline‐3,2′‐pyrrolidine‐3′,3″‐quinoline] and spiro[imidazole‐4,3′‐quinoline] have been developed from quinolone derivative adopting modern synthetic methodologies. 相似文献
8.
Ottorino DeLucchi Arif Datan Aliye Altunda Fabrizio Fabris Metin Balci 《Helvetica chimica acta》2004,87(9):2364-2367
An efficient synthetic route to the concave‐shaped, potentially ionophoric syn‐ and anti‐isomers of 5,6,11,12,17,18‐hexahydro‐5,18:6,11:12,17‐triepoxytrinaphthylene ( 4 ) was elaborated. Starting from ‘oxabenzonorbornadiene’ ( 5 ), the stannylated precursor 9 was prepared in three steps, followed by cyclotrimerization catalyzed by copper(I) thiophene‐2‐carboxylate (CuTC) , which afforded 4 in a syn/anti ratio of 5 : 4. 相似文献
9.
Feng Cheng Subarna Jyoti Kalita Zhen‐Ni Zhao Xing Yang Yan Zhao Uwe Schneider Norio Shibata Yi‐Yong Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(46):16790-16796
A CuII‐catalyzed asymmetric 1,3‐dipolar cycloaddition using β‐fluoroalkyl alkenyl arylsulfones as dipolarophiles and glycine/alanine iminoesters as azomethine ylide precursors has been developed. Remarkably, a catalyst loading as low as 0.5 mol % is highly efficient. Accordingly, a wide range of enantioenriched 3‐fluoroalkyl pyrrolidines, as well as Δ2‐pyrroline and pyrrole derivatives, are generated in good to excellent yields with high asymmetric induction. This synthetic approach is diastereodivergent in that exo‐adducts could be converted into the corresponding exo′‐adducts by 1,8‐diazabicyclo[5.4.0]undec‐7‐ene mediated epimerization at C2 of the pyrrolidine core. The free‐energy profiles from DFT calculations suggest the Michael addition of the 1,3‐dipole to be the rate‐ and enantiodetermining step, and the origin of stereoselectivity is studied by means of the noncovalent interaction (NCI) analysis. 相似文献
10.
(S,S)‐2‐Substituted‐4,4‐diphenyl‐3,1‐oxazabicyclo[3.3.0]octanes were synthesized diaster‐eospecifically from aldehydes and (S)‐2‐(hydroxydiphenylmethyl)pyrrolidine, which was obtained from L ‐proline, under acid‐catalyzed conditions in anhydrous toluene. The stereospecificity of the condensation reaction is discussed. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:42–45, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10064 相似文献
11.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(14):4060-4063
An enantioselective iridium‐catalyzed allylic substitution with a set of highly unstabilized nucleophiles generated in situ from 2‐methylpyridines is described. Enantioenriched 2‐substituted pyridines, which are frequently encountered in natural products and pharmaceuticals, could be easily constructed by this simple method in good yields and excellent enantioselectivity. The synthetic utility of the pyridine products is demonstrated through the synthesis of a key intermediate of a reported Na+/H+ exchanger inhibitor and the total synthesis of (−)‐lycopladine A. 相似文献
12.
Dual stimuli‐responsive polyamines derived from modified N‐vinylpyrrolidones through CuAAC click chemistry 下载免费PDF全文
Anselmo del Prado Rodrigo Navarro Pavel Levkin Alberto Gallardo Carlos Elvira Helmut Reinecke 《Journal of polymer science. Part A, Polymer chemistry》2016,54(8):1098-1108
The synthesis via copper(I)‐catalyzed azide alkyne cycloaddition (CuAAC) of three new monomer derivatives of N‐vinyl‐2‐pyrrolidone (VP) carrying cyclic pyrrolidine, piperidine, and piperazine groups and the corresponding copolymers with unmodified VP is shown. The systems bearing pyrrolidine and piperidine displayed both thermo‐ and pH‐response, which has not been reported previously for a polymer with polyvinylpyrrolidone (PVP) backbone. A broad modulation of the LCST with the copolymer composition and pH was observed in a temperature range 0–100 °C. The polymers carrying piperazine exhibited broad buffering regions and no thermosensitivity. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1098–1108 相似文献
13.
Mukesh Pappoppula Prof. Aaron Aponick 《Angewandte Chemie (International ed. in English)》2015,54(52):15827-15830
An enantioselective total synthesis of martinellic acid is described. The pyrroloquinoline alkaloid core is efficiently prepared from a quinoline, employing a method which relies on a newly developed Cu‐catalyzed enantioselective alkynylation using the chiral imidazole‐based biaryl P,N ligand StackPhos to establish the absolute stereochemistry. The remaining carbon atoms are then installed by means of a diastereoselective Pd‐catalyzed decarboxylative allylation and the synthesis is completed after straightforward functional‐group manipulation. This new synthetic method enables the most concise enantioselective synthesis of this important class of molecules to date. 相似文献
14.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(15):4265-4269
A carbene‐catalyzed intermolecular C−N bond formation, which initiates a highly selective cascade reaction for the synthesis of pyrrolidine fused β‐lactones, is disclosed. The nitrogen‐containing bicyclic β‐lactone products are obtained with good yields and excellent stereoselectivities. Synthetic transformations of the reaction products into useful functional molecules, such as amino catalysts, can be efficiently realized under mild reaction conditions. Mechanistically, this study provides insights into modulating the reactivities of heteroatoms, such as nitrogen atoms, in challenging carbene‐catalyzed asymmetric carbon–heteroatom bond‐forming reactions. 相似文献
15.
《Angewandte Chemie (International ed. in English)》2017,56(15):4201-4205
A carbene‐catalyzed intermolecular C−N bond formation, which initiates a highly selective cascade reaction for the synthesis of pyrrolidine fused β‐lactones, is disclosed. The nitrogen‐containing bicyclic β‐lactone products are obtained with good yields and excellent stereoselectivities. Synthetic transformations of the reaction products into useful functional molecules, such as amino catalysts, can be efficiently realized under mild reaction conditions. Mechanistically, this study provides insights into modulating the reactivities of heteroatoms, such as nitrogen atoms, in challenging carbene‐catalyzed asymmetric carbon–heteroatom bond‐forming reactions. 相似文献
16.
Gold(I)‐Catalyzed Tandem Transformation with Diynes: Rapid Access to Linear Cyclopentenone‐Fused Polycyclic Molecules 下载免费PDF全文
Congjun Yu Bin Chen Tian Zhou Qingshan Tian Prof. Dr. Guozhu Zhang 《Angewandte Chemie (International ed. in English)》2015,54(37):10903-10907
An efficient and convenient synthesis of useful linear cyclopentenone‐fused polycyclic compounds has been achieved through a novel gold(I)‐catalyzed transformation of diynes. The method demonstrates high product yields and tolerates of a wide variety of important functional groups. Gold‐vinylidene formation, methoxy group migration, and Nazarov‐type cyclization are proposed to be the key steps in the reaction pathway. The synthetic utility of this method is demonstrated by converting the product to eight‐membered‐ring‐fused compound. 相似文献
17.
Pd‐Catalyzed Carboamination of Alkylidenecyclopropanes: Synthesis of Congested Pyrrolidines and Piperidines 下载免费PDF全文
Phillip R. Lazzara Keegan P. Fitzpatrick Dr. Chad C. Eichman 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(47):16779-16782
The synthesis of densely functionalized N‐heterocycles is an ongoing challenge in chemical synthesis. Herein, we report an efficient method for the construction of pyrrolidine and piperidine scaffolds using a palladium‐catalyzed carboamination of alkylidenecyclopropanes. 相似文献
18.
Nickel‐Catalyzed Heck‐Type Monofluoroacetation of Styrenes for Facile Synthesis of Allylic Fluorides 下载免费PDF全文
Zhen‐Yu Wang Jia‐Hao Wan Gao‐Yin Wang Ruo‐Xing Jin Dr. Quan Lan Prof. Dr. Xi‐Sheng Wang 《化学:亚洲杂志》2018,13(3):261-265
An efficient nickel‐catalyzed Heck‐type reaction between styrenes and fluoroalkyl iodine has been developed. This novel transformation has demonstrated a broad substrate scope, mild reaction conditions and excellent E‐stereoselectivity. This efficient synthetic method has been applied to the late‐stage monofluoroacetation of biologically active molecules. Mechanistic investigations indicate that a monofluoroalkyl radical is involved in the catalytic cycle. 相似文献
19.
Shou‐Guo Wang Yang Liu Nicolai Cramer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(50):18304-18308
An efficient CpxRhIII‐catalyzed enantioselective alkenyl C?H functionalization/[4+1] annulation of acryl amides and allenes is reported. The described transformation provides straightforward access to enantioenriched α,β‐unsaturated‐γ‐lactams bearing a quaternary stereocenter. The reaction operates under mild conditions, displays a broad functional‐group tolerance, and provides 2H‐pyrrol‐2‐ones with excellent selectivity of up to 97:3 er. Such scaffolds are frequently found in natural products and synthetic bioactive compounds and are of significant synthetic value. It is noteworthy that the allene serves as a one‐carbon unit in the [4+1]‐annulation. 相似文献
20.
Enantiodivergent Synthesis of (+)‐ and (−)‐Pyrrolidine 197B: Synthesis of trans‐2,5‐Disubstituted Pyrrolidines by Intramolecular Hydroamination 下载免费PDF全文
Dr. Sixto J. Pérez Dr. Martín A. Purino Daniel A. Cruz Juan M. López‐Soria Dr. Rubén M. Carballo Prof. Miguel A. Ramírez Dr. Israel Fernández Prof. Víctor S. Martín Dr. Juan I. Padrón 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(43):15529-15535
A highly efficient, diastereoselective, iron(III)‐catalyzed intramolecular hydroamination/cyclization reaction involving α‐substituted amino alkenes is described. Thus, enantiopure trans‐2,5‐disubstituted pyrrolidines and trans‐5‐substituted proline derivatives were synthesized by means of a combination of enantiopure starting materials, easily available from l ‐α‐amino acids, with sustainable metal catalysts such as iron(III) salts. The scope of this methodology is highlighted in an enantiodivergent approach to the synthesis of both (+)‐ and (?)‐pyrrolidine 197B alkaloids from l ‐glutamic acid. In addition, a computational study was carried out to gain insight into the complete diastereoselectivity of the transformation. 相似文献