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Cuprous acetylides react with aryl halides to yield aryl acetylenes and with o-halophenols to give benzofurans.1,2 The broad scope of this latter reaction for the synthesis of benzofuran natural products is shown by application inter alia to norlignans,3 euparinoids,4 phytoalexins,5 furanocoumarins,6 fomannoxin,7 isotubaic acid8 and machicendiol. 相似文献
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Arunachalam Sagadevan Ayyakkannu Ragupathi Kuo Chu Hwang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(47):14102-14107
The first successful example of a visible‐light‐induced copper‐catalyzed process for C H annulation of arylamines with terminal alkynes and benzoquinone is described. This three‐component reaction allows use of a variety of commercial terminal alkynes as coupling partners for the one‐step regioselective synthesis of functionalized indoles. Moreover, the current process represents a sustainable and atom‐economical approach for the preparation of complex indoles from easily accessible starting materials under visible‐light irradiation, without the need for expensive metals and harsh reaction conditions. 相似文献
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Photoinduced Copper‐Catalyzed Regioselective Synthesis of Indoles: Three‐Component Coupling of Arylamines,Terminal Alkynes,and Quinones
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Dr. Arunachalam Sagadevan Ayyakkannu Ragupathi Prof. Kuo Chu Hwang 《Angewandte Chemie (International ed. in English)》2015,54(47):13896-13901
The first successful example of a visible‐light‐induced copper‐catalyzed process for C? H annulation of arylamines with terminal alkynes and benzoquinone is described. This three‐component reaction allows use of a variety of commercial terminal alkynes as coupling partners for the one‐step regioselective synthesis of functionalized indoles. Moreover, the current process represents a sustainable and atom‐economical approach for the preparation of complex indoles from easily accessible starting materials under visible‐light irradiation, without the need for expensive metals and harsh reaction conditions. 相似文献
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A soluble polymer-supported synthesis of indoles via palladium-mediated heteroannulation of terminal alkynes with o-iodoanilines has been described. The protocol provides a useful tool for constructing combinatorial indole libraries. 相似文献
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Dr. Florian Albrecht Dulce Rey Dr. Shadi Fatayer Dr. Fabian Schulz Dr. Dolores Pérez Dr. Diego Peña Dr. Leo Gross 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(51):23189-23193
Glaser-like coupling of terminal alkynes by thermal activation is extensively used in on-surface chemistry. Here we demonstrate an intramolecular version of this reaction performed by atom manipulation. We used voltage pulses from the tip to trigger a Glaser-like coupling between terminal alkyne carbons within a custom-synthesized precursor molecule adsorbed on bilayer NaCl on Cu(111). Different conformations of the precursor molecule and the product were characterized by molecular structure elucidation with atomic force microscopy and orbital density mapping with scanning tunneling microscopy, accompanied by density functional theory calculations. We revealed partially dehydrogenated intermediates, providing insight into the reaction pathway. 相似文献
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V. M. Lyubchanskaya L. M. Alekseeva S. A. Savina V. G. Granik 《Chemistry of Heterocyclic Compounds》2003,39(1):61-64
The reaction of naphthoquinone with nitroenamines and the interaction of benzimidazolequinones with derivatives of -aminocrotonic ester have been studied. It was shown that in the first case only the synthesis of naphthofurans occurs but in the second imidazoindoles are formed. 相似文献
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A cobalt-catalyzed reductive coupling of terminal alkynes, RC?CH, with activated alkenes, R'CH?CH(2) , in the presence of zinc and water to give functionalized trans-disubstituted alkenes, RCH?CHCH(2) CH(2) R', is described. A variety of aromatic terminal alkynes underwent reductive coupling with activated alkenes including enones, acrylates, acrylonitrile, and vinyl sulfones in the presence of a CoCl(2) /P(OMe)(3) /Zn catalyst system to afford 1,2-trans-disubstituted alkenes with high regio- and stereoselectivity. Similarly, aliphatic terminal alkynes also efficiently participated in the coupling reaction with acrylates, enones, and vinyl sulfone, in the presence of the CoCl(2) /P(OPh)(3) /Zn system providing a mixture of 1,2-trans- and 1,1-disubstituted functionalized terminal alkene products in high yields. The scope of the reaction was also extended by the coupling of 1,3-enynes and acetylene gas with alkenes. Furthermore, a phosphine-free cobalt-catalyzed reductive coupling of terminal alkynes with enones, affording 1,2-trans-disubstituted alkenes as the major products in a high regioisomeric ratio, is demonstrated. In the reactions, less expensive and air-stable cobalt complexes, a mild reducing agent (Zn) and a simple hydrogen source (water) were used. A possible reaction mechanism involving a cobaltacyclopentene as the key intermediate is proposed. 相似文献
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Terminal alkynes couple smoothly in the presence of Phl(OAc)2 or Phl(OH)OTs, catalytic amount of Cul and base, affording conjugated diynes. 相似文献
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Avijit Hazra Mitchell T. Lee Justin F. Chiu Prof. Gojko Lalic 《Angewandte Chemie (International ed. in English)》2018,57(19):5492-5496
We have developed a photoinduced copper‐catalyzed alkylation of terminal alkynes with primary, secondary, or tertiary alkyl iodides as electrophiles. The reaction has a broad substrate scope and can be successfully performed in the presence of ester, nitrile, aryl halide, ketone, sulfonamide, epoxide, alcohol, and amide functional groups. The alkylation is promoted by blue light (λ≈450 nm) and proceeds at room temperature in the absence of any additional metal catalysts. The use of a terpyridine ligand is essential for the success of the reaction and is shown to prevent photoinduced copper‐catalyzed polymerization of the starting materials. 相似文献
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Dr. Rosana Álvarez Claudio Martínez Youssef Madich J. Gabriel Denis Dr. José M. Aurrecoechea Prof. Dr. Ángel R. de Lera 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(42):12746-12753
Structurally diverse C3‐alkenylbenzofurans, C3‐alkenylindoles, and C4‐alkenylisoquinolones are efficiently prepared by using consecutive Sonogashira and cascade Pd‐catalyzed heterocyclization/oxidative Heck couplings from readily available ortho‐iodosubstituted phenol, aniline, and benzamide substrates, alkynes, and functionalized olefins. The cyclization of O‐ and N‐heteronucleophiles follows regioselective 5‐endo‐dig‐ or 6‐endo‐dig‐cyclization modes, whereas the subsequent Heck‐type coupling with both mono‐ and disubstituted olefins takes place stereoselectively with exclusive formation of the E isomers in most cases. 相似文献
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Cobalt(III)‐Catalyzed Intramolecular Cross‐Dehydrogenative C−H/X−H Coupling: Efficient Synthesis of Indoles and Benzofurans
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Jayanta Ghorai Angula Chandra Shekar Reddy Prof. Dr. Pazhamalai Anbarasan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(45):16042-16046
An efficient cobalt(III)‐catalyzed intramolecular cross‐dehydrogenative C?H/N?H coupling of ortho‐alkenylanilines has been developed utilizing O2 as a terminal oxidant. The developed reaction tolerates various reactive functional groups and allows the synthesis of diverse indole derivatives in good to excellent yields. The method was successfully extended to the synthesis of benzofurans through the intramolecular cross‐dehydrogenative C?H/O?H coupling of ortho‐alkenylphenols. 相似文献
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Dr. Subramaniyan Mannathan Prof. Dr. Chien‐Hong Cheng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(37):11771-11777
A cobalt‐catalyzed reductive coupling of terminal alkynes, RC?CH, with activated alkenes, R′CH?CH2, in the presence of zinc and water to give functionalized trans‐disubstituted alkenes, RCH?CHCH2CH2R′, is described. A variety of aromatic terminal alkynes underwent reductive coupling with activated alkenes including enones, acrylates, acrylonitrile, and vinyl sulfones in the presence of a CoCl2/P(OMe)3/Zn catalyst system to afford 1,2‐trans‐disubstituted alkenes with high regio‐ and stereoselectivity. Similarly, aliphatic terminal alkynes also efficiently participated in the coupling reaction with acrylates, enones, and vinyl sulfone, in the presence of the CoCl2/P(OPh)3/Zn system providing a mixture of 1,2‐trans‐ and 1,1‐disubstituted functionalized terminal alkene products in high yields. The scope of the reaction was also extended by the coupling of 1,3‐enynes and acetylene gas with alkenes. Furthermore, a phosphine‐free cobalt‐catalyzed reductive coupling of terminal alkynes with enones, affording 1,2‐trans‐disubstituted alkenes as the major products in a high regioisomeric ratio, is demonstrated. In the reactions, less expensive and air‐stable cobalt complexes, a mild reducing agent (Zn) and a simple hydrogen source (water) were used. A possible reaction mechanism involving a cobaltacyclopentene as the key intermediate is proposed. 相似文献