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101.
Inside Back Cover: A Gold(I)‐Catalyzed Domino Coupling of Alcohols with Allenes Enables the Synthesis of Highly Substituted Indenes (Chem. Eur. J. 41/2016)
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102.
Highly Functionalized Cyclopentane Derivatives by Tandem Michael Addition/Radical Cyclization/Oxygenation Reactions
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Ing. Martin Holan Dr. Radek Pohl Dr. Ivana Císařová Dr. Blanka Klepetářová Prof. Dr. Peter G. Jones Dr. Ullrich Jahn 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9877-9888
Densely functionalized cyclopentane derivatives with up to four consecutive stereocenters are assembled by a tandem Michael addition/single‐electron transfer oxidation/radical cyclization/oxygenation strategy mediated by ferrocenium hexafluorophosphate, a recyclable, less toxic single‐electron transfer oxidant. Ester enolates were coupled with α‐benzylidene and α‐alkylidene β‐dicarbonyl compounds with switchable diastereoselectivity. This pivotal steering element subsequently controls the diastereoselectivity of the radical cyclization step. The substitution pattern of the radical cyclization acceptor enables a switch of the cyclization mode from a 5‐exo pattern for terminally substituted olefin units to a 6‐endo mode for internally substituted acceptors. The oxidative anionic/radical strategy also allows efficient termination by oxygenation with the free radical 2,2,6,6‐tetramethyl‐1‐piperidinoxyl, and two C?C bonds and one C?O bond are thus formed in the sequence. A stereochemical model is proposed that accounts for all of the experimental results and allows the prediction of the stereochemical outcome. Further transformations of the synthesized cyclopentanes are reported. 相似文献
103.
Regio‐ and Chemoselective N‐1 Acylation of Indoles: Pd‐Catalyzed Domino Cyclization to Afford 1,2‐Fused Tricyclic Indole Scaffolds
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Yongxian Liu Yuanqiong Huang Hongjian Song Yuxiu Liu Prof. Qingmin Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(14):5337-5340
A concise method for the synthesis of 1,2‐fused tricyclic indole scaffolds by domino cyclization involving a Pd‐catalyzed Sonogashira coupling, indole cyclization, regio‐ and chemoselective N‐1 acylation, and 1,4‐Michael addition is reported. This method provides straightforward access to tetrahydro[1,4]diazepino[1,2‐a]indole and hexahydro[1,5]diazocino[1,2‐a]indole scaffolds. 相似文献
104.
105.
Chanikan Duangjan Vatcharin Rukachaisirikul Saowanit Saithong Juthanat Kaeobamrung 《Tetrahedron letters》2018,59(39):3537-3540
Quinazolinediones were obtained from 2-iodobenzoic acids and carbodiimide derivatives under mild reaction conditions via a copper-catalyzed domino reaction. The absence of an external base was essential to avoid the generation of amide by-products. Both alkyl- and aryl-substituted carbodiimides gave the corresponding quinazolinediones. However, the use of aryl-substituted carbodiimides resulted in low yields due to an undesired elimination process. 相似文献
106.
An efficient and modest protocol has been utilized for the synthesis of bicyclic dilactam derivatives through one-pot multicomponent domino reaction starting from various cyclic ketones under mild condition. The synthesized motif shows four stereogenic centers with two quaternary amine functionalities and such molecular arrangements are very fascinating and rare to obtain. We propose a mechanism for the formation of bicyclic dilactams through aldol condensation/condensation of cyanoacetamides/cyclization of condensed intermediate. 相似文献
107.
Solvent‐Mediated Functionalization of Benzofuroxan on Electron‐Rich Ruthenium Complex Platform
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Dr. Prabir Ghosh Sanchaita Dey Sanjib Panda Prof. Goutam Kumar Lahiri 《化学:亚洲杂志》2018,13(12):1582-1593
An unprecedented reactivity profile of biochemically relevant R‐benzofuroxan (R=H, Me, Cl), with high structural diversity and molecular complexity on a selective {Ru(acac)2} (acac=acetylacetonate) platform, in conjugation with EtOH solvent mediation, is revealed. This led to the development of monomeric [RuIII(acac)2(L1R)] ( 1 a – 1 c ; L1R=2‐nitrosoanilido derivatives) and dimeric [{RuII(acac)2}2(L2R)] ( 2 a – 2 b ; L2R=(1E,2E)‐N1,N2‐bis(2‐nitrosophenyl)ethane‐1,2‐diimine derivatives) complexes in one pot with a change in the metal redox conditions. The functionalization of benzofuroxan in 1 and 2 implied in situ reduction of N=O to NH? in the former and solvent‐assisted multiple N?C coupling in the latter. The aforesaid transformation processes were authenticated through structural elucidation of representative complexes, and evaluated by their spectroscopic/electrochemical features, along with C2D5OD labeling and monitoring of the impact of substituents (R) in the benzofuroxan framework on the product distribution process. The noninnocent potential of newly developed L1 and L2 in 1 and 2 , respectively, was also probed by spectroelectrochemistry in combination with DFT calculations. 相似文献
108.
A self diastereoselective, simple metal free and efficient branch domino reaction gave multiple heteroaryl substituted (±) cyclohexanols with five chiral centres in >95% yields. The reactions that occur are Claisen Schmidt condensation followed by Michael addition and Aldol reactions of heteroaryl carbaldehydes and acetyl pyridine derivatives. Mechanistic study of the reactions shows excellent self diastereoselectivity (dr > 99%) in the intermediate steps which results selectively in the formation of one set of enantiomers out of sixteen possible enantiomeric pairs. The self diastereoselectivity of reaction in all the steps dominates due to the steric hindrance induced by the bulky heteroaryl groups. The stereochemistry of the synthesized compounds is established using single crystal XRD. 相似文献
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