共查询到20条相似文献,搜索用时 15 毫秒
1.
Zhuo Xin Dr. Søren Kramer Dr. Jacob Overgaard Prof. Dr. Troels Skrydstrup 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(26):7926-7930
A new synthetic route to the privileged 1,2‐dihydroisoquinolines is reported. This method, which relies on a gold‐catalyzed formal [4+2] cycloaddition between ynamides and imines, provides a new retrosynthetic disconnection of the 1,2‐dihydroisoquinoline core by installing the 1,8a C?C and 2,3 C?N bonds in one step. Both aldimines and ketimines can be used as substrates. In addition, one example of dihydrofuropyridine synthesis is also demonstrated. 相似文献
2.
Gold‐Catalyzed Cascade Cyclization of 2‐Alkynyl‐N‐Propargylanilines by Rearrangement of a Propargyl Group 下载免费PDF全文
Yusuke Tokimizu Dr. Shinya Oishi Prof. Dr. Nobutaka Fujii Prof. Dr. Hiroaki Ohno 《Angewandte Chemie (International ed. in English)》2015,54(27):7862-7866
Gold catalysis enables direct construction of tetracyclic fused indolines through the migration of a propargyl substituent from an aniline nitrogen atom to the C3‐position of an indole from 2‐alkynyl‐N‐propargylanilines. This reaction provides rapid access to fused three‐dimensional indolines in a single operation with the formation of four bonds and three rings. 相似文献
3.
Ana Escribano‐Cuesta Verónica López‐Carrillo Dominic Janssen Dr. Antonio M. Echavarren Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(23):5646-5650
Gold and rings : The gold(I)‐catalyzed addition of aldehydes to 1,6‐enynes gives 1,3‐dienes, by a cycloaddition/fragmentation process. 1,5‐Enynes react with aldehydes and ketones by the 5‐endo‐dig pathway to give the corresponding cycloadducts.
4.
Atom‐Economic Synthesis of Fully Substituted 2‐Aminopyrroles via Gold‐Catalyzed Formal [3+2] Cycloaddition between Ynamides and Isoxazoles 下载免费PDF全文
Xin‐Yu Xiao Ai‐Hua Zhou Chao Shu Fei Pan Dr. Ting Li Prof. Dr. Long‐Wu Ye 《化学:亚洲杂志》2015,10(9):1854-1858
A concise and flexible synthesis of fully substituted 2‐aminopyrroles via gold‐catalyzed formal [3+2] cycloaddition between ynamides and isoxazoles has been developed. Under mild reaction conditions, various 2‐aminopyrrole derivatives were obtained in good to excellent yields, thus providing an efficient and atom‐economic way for the construction of fully substituted 2‐aminopyrroles. 相似文献
5.
6.
Mathias Schelwies Dr. Ralph Moser Adrian L. Dempwolff Frank Rominger Dr. Günter Helmchen Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(41):10888-10900
A full account of a recently discovered gold(I)‐catalyzed reaction, a cycloaddition of carbonyl compounds to enynes yielding 2‐oxabicyclo[3.1.0]hexanes with four stereogenic centers, is presented. The reaction proceeds with very high diastereoselectivity. The scope of the reaction has been investigated. In addition, experiments and DFT calculations concerning mechanistic aspects were carried out. The reaction course varies with the substitution pattern of the alkene moiety of the starting enyne. Branched olefins led to 2‐oxabicyclo[3.1.0]hexanes; terminally substituted olefins proceeded with the incorporation of two carbonyl components to give hexahydrocyclopenta[d][1,3]dioxines. 相似文献
7.
Gold(I)‐Catalyzed 1,2‐Acyloxy Migration/[3+2] Cycloaddition of 1,6‐Diynes with an Ynamide Propargyl Ester Moiety: Highly Efficient Synthesis of Functionalized Cyclopenta[b]indoles 下载免费PDF全文
Dr. Jun Liu Ming Chen Liangwei Zhang Prof. Yuanhong Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(3):1009-1013
A gold‐catalyzed cycloisomerization of 1,6‐diynes containing an ynamide propargyl ester or carbonate moiety has been developed that provides an attractive route to a diverse‐substituted 3‐acyloxy‐1,4‐dihydrocyclopenta[b]indoles. Mechanistic studies indicate that the reaction likely proceeds through a competitive 1,2‐OAc migration followed by [3+2] cycloaddition of the vinyl gold–carbenoid intermediate with the pendant triple bond. The synthetic utility of the obtained cyclopenta[b]indole products was demonstrated by their efficient transformations by deprotection or double‐bond isomerization reactions. 相似文献
8.
Nan Li Tian‐Yi Wang Prof. Dr. Liu‐Zhu Gong Prof. Dr. Liming Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3585-3588
An unprecedented gold‐catalyzed multiple cascade reaction between 2‐alkynyl arylazides and alkynols has been developed, allowing for the step‐economical synthesis of pyrroloindolone derivatives with a wide range of structural diversity. In this reaction, the gold complex participates in triple catalysis in tandem fashion. Moreover, the efficient chirality transfer from optically pure alkynol substrates enables facile access to chiral pyrroloindolone derivatives with two stereogenic centers, including a quaternary one, with excellent levels of optical purity. 相似文献
9.
Teresa de Haro Prof. Dr. Enrique Gómez‐Bengoa Dr. Riccardo Cribiú Dr. Xiaogen Huang Prof. Dr. Cristina Nevado 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(22):6811-6824
The late transition metal catalyzed rearrangement of propargyl acetates offers an interesting platform for the development of synthetically useful transformations. We have recently shown that gold complexes can catalyze a highly selective tandem 1,2‐/1,2‐bis‐acetoxy migration in 1,4‐bis‐propargyl acetates to form 2,3‐bis‐acetoxy‐1,3‐dienes. In this way, (1Z,3Z)‐ or (1Z,3E)‐ and (1E,3Z)‐1,3‐dienes could be obtained in a stereocontrolled manner depending on the electronic and steric features of the ancillary ligand bound to gold and the substituents at the propargylic positions. In this work, we report an experimental study on the scope of this transformation, plus a detailed theoretical examination of the reaction mechanism, which has revealed the key features responsible for the reaction stereoselectivity. Synthetic applications towards the one‐pot synthesis of quinoxaline heterocycles and tandem Diels–Alder processes have also been devised. 相似文献
10.
11.
Gold‐Catalyzed Ring Expansion of Alkynyl Heterocycles through 1,2‐Migration of an Endocyclic Carbon–Heteroatom Bond 下载免费PDF全文
Ming Chen Ning Sun Wei Xu Jidong Zhao Gaonan Wang Prof. Yuanhong Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(51):18571-18575
A mild and efficient gold‐catalyzed oxidative ring‐expansion of a series of alkynyl heterocycles using pyridine‐N‐oxide as the oxidant has been developed, which affords highly valuable six‐ or seven‐membered heterocycles with wide functional group toleration. The reaction consists of a regioselective oxidation and a chemoselective migration of an endocyclic carbon–heteroatom bond (favored over C?H migration) with the order of migratory aptitude for carbon–heteroatom bonds being C?S>C?N>C?O. In the absence of an oxidant, polycyclic products are readily constructed through a ring‐expansion/Nazarov cyclization reaction sequence. 相似文献
12.
Gold‐Catalyzed 6‐Exo‐Dig Cycloisomerization: A Versatile Approach to Functionalized Phenanthrenes 下载免费PDF全文
A novel gold‐catalyzed 6‐exo‐dig cycloisomerization of o‐propargylbiaryls has been developed that provides ready access to functionalized phenanthrenes in largely good to excellent yields. Notable features of this method are readily available starting materials, mild reaction conditions, and broad substrate scope. 相似文献
13.
14.
Competitive Gold‐Promoted Meyer–Schuster and oxy‐Cope Rearrangements of 3‐Acyloxy‐1,5‐enynes: Selective Catalysis for the Synthesis of (+)‐(S)‐γ‐Ionone and (−)‐(2S,6 R)‐cis‐γ‐Irone 下载免费PDF全文
Dr. Serena Bugoni Dr. Valentina Merlini Dr. Alessio Porta Dr. Sylvain Gaillard Prof. Giuseppe Zanoni Prof. Dr. Steven P. Nolan Prof. Giovanni Vidari 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(40):14068-14074
We report a simple, highly stereoselective synthesis of (+)‐(S)‐γ‐ionone and (‐)‐(2S,6R)‐cis‐γ‐irone, two characteristic and precious odorants; the latter compound is a constituent of the essential oil obtained from iris rhizomes. Of general interest in this approach are the photoisomerization of an endo trisubstituted cyclohexene double bond to an exo vinyl group and the installation of the enone side chain through a [(NHC)AuI]‐catalyzed Meyer–Schuster‐like rearrangement. This required a careful investigation of the mechanism of the gold‐catalyzed reaction and a judicious selection of reaction conditions. In fact, it was found that the Meyer–Schuster reaction may compete with the oxy‐Cope rearrangement. Gold‐based catalytic systems can promote either reaction selectively. In the present system, the mononuclear gold complex [Au(IPr)Cl], in combination with the silver salt AgSbF6 in 100:1 butan‐2‐one/H2O, proved to efficiently promote the Meyer–Schuster rearrangement of propargylic benzoates, whereas the digold catalyst [{Au(IPr)}2(μ‐OH)][BF4] in anhydrous dichloromethane selectively promoted the oxy‐Cope rearrangement of propargylic alcohols. 相似文献
15.
16.
Xiaogen Huang Dr. Teresa de Haro Cristina Nevado Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(24):5904-5908
Change the ligand, change the stereochemistry : 2,3‐Bis(acetoxy)‐1,3‐dienes are obtained in a stereocontrolled manner by a novel tandem 1,2‐/1,2‐bis(acetoxy) rearrangement (see scheme, R1 and R2 are δ+ stabilizing). Upon stabilization of the reaction intermediates, the ligand attached to gold controls the stereochemistry of the alkene in the second acetate migration, that is, N‐heterocyclic carbenes (NHC) favor cis alkenes, whereas phosphine ligands selectively afford trans olefins.
17.
Regiocontrolled Gold‐Catalyzed [2+2+2] Cycloadditions of Ynamides with Two Discrete Nitriles to Construct 4‐Aminopyrimidine Cores 下载免费PDF全文
Somnath Narayan Karad Prof. Dr. Rai‐Shung Liu 《Angewandte Chemie (International ed. in English)》2014,53(34):9072-9076
Reported herein is the novel gold‐catalyzed intermolecular [2+2+2] cycloaddition of ynamides with two discrete nitriles to form monomeric 4‐aminopyrimidines, which are pharmaceutically important structural motifs. The utility of this new cycloaddition is demonstrated by the excellent regioselectivity obtained using a variety of ynamides and nitriles. 相似文献
18.
Guozhu Zhang Yu Peng Dr. Li Cui Dr. Liming Zhang Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(17):3112-3115
Oxidizing gold? A gold(I)/gold(III) catalytic cycle is essential for the first oxidative cross‐coupling reaction in gold catalysis. By using Selectfluor for gold(I) oxidation, this chemistry reveals the synthetic potential of incorporating gold(I)/gold(III) catalytic cycles into contemporary gold chemistry and promises a new area of gold research by merging powerful gold catalysis and oxidative metal‐catalyzed cross‐coupling reactions.
19.
Jacob C. Timmerman Bradley D. Robertson Prof. Ross A. Widenhoefer 《Angewandte Chemie (International ed. in English)》2015,54(7):2251-2254
The cationic gold phosphine complex [{PCy2(o‐biphenyl)}Au(NCMe)]+SbF6? (Cy=cyclohexyl) catalyzes the intermolecular, anti‐Markovnikov hydroamination reaction of monosubstituted and cis‐ and trans‐disubstituted alkylidenecyclopropanes (ACPs) with imidazolidin‐2‐ones and other nucleophiles. This reaction forms 1‐cyclopropyl alkylamine derivatives in high yield and with high regio‐ and diastereoselectivity. NMR spectroscopic analysis of gold π‐ACP complexes and control experiments point to the sp hybridization of the ACP internal alkene carbon atom as controlling the regiochemistry of the ACP hydroamination reaction. 相似文献
20.