- Rhodium-catalyzed 1,4-addition of terminal alkynes to vinyl ketones
-
The metal complex Rh(acac)(CO)2 in the presence of an eqimolar amount of tris(o-methoxyphenyl)phosphine provides a useful catalyst system for the 1,4-addition of alkynes to unsubstituted vinyl ketones. Best yields are obtained when the transfor
- Lerum, Ronald V.,Chisholm, John D.
-
-
Read Online
- The first palladium-catalyzed 1,4-addition of terminal alkynes to conjugated enones
-
The first palladium-catalyzed 1,4-addition of terminal alkynes to conjugated enones has been developed in water and in acetone, producing the corresponding γ,δ-alkynyl ketones in high yields.
- Chen, Liang,Li, Chao-Jun
-
-
Read Online
- Enantioselective Nickel-Catalyzed anti-Arylmetallative Cyclizations onto Acyclic Ketones
-
Domino reactions involving nickel-catalyzed additions of (hetero)arylboronic acids to alkynes, followed by cyclization of the alkenylnickel intermediates onto tethered acyclic ketones to give chiral tertiary-alcohol-containing products in high enantioselectivities, are described. The reversible E/Z isomerization of the alkenylnickel intermediates enables overall anti-arylmetallative cyclization to occur. The ring system of the products are substructures of certain diarylindolizidine alkaloids.
- Green, Harley,Argent, Stephen P.,Lam, Hon Wai
-
supporting information
p. 5897 - 5900
(2021/03/16)
-
- K2CO3-Mediated Cyclization and Rearrangement of γ,δ-Alkynyl Oximes to Form Pyridols
-
A novel K2CO3-mediated cyclization and rearrangement of γ,δ-alkynyl oximes for the synthesis of pyridols is described. The process accomplishes an efficient [1,3] rearrangement of the O-vinyl oxime intermediate which is in situ generated from the intramolecular nucleophilic addition of γ,δ-alkynyl oximes. The reaction employs readily accessible starting materials, tolerates a wide range of functional groups, and gives a variety of synthetically challenging pyridols in good yields.
- Wang, Shun,Guo, Yong-Qiang,Ren, Zhi-Hui,Wang, Yao-Yu,Guan, Zheng-Hui
-
supporting information
p. 1574 - 1577
(2017/04/13)
-
- Gold-catalyzed enantioselective ring-expanding cycloisomerization of cyclopropylidene bearing 1,5-enynes
-
An enantioselective ring-expanding cycloisomerization of 1,5-enynes bearing a cyclopropylidene moiety has been developed. This methodology provides a new approach to bicyclo[4.2.0]octanes, a structural motif present in many biologically active natural products.
- Zheng, Hongchao,Felix, Ryan J.,Gagne, Michel R.
-
supporting information
p. 2272 - 2275
(2014/05/06)
-
- Direct conjugate addition of alkynes with α,β-unsaturated carbonyl compounds catalyzed by NCN-pincer Ru complexes
-
NCN-pincer Ru-complexes containing bis(oxazolinyl)phenyl ligands serve as suitable catalysts in the direct conjugate additions of α,β- unsaturated carbonyl compounds, including ketones, esters, and amides, as well as vinylphosphonates, giving various β-alkynyl carbonyl and phosphonate compounds. A bis(oxazolinyl)phenyl (phebox)-Ru complex also catalyzes the asymmetric conjugate addition of an alkyne with a β-substituted, α,β-unsaturated ketone to produce a chiral β-alkynyl ketone. Copyright
- Ito, Jun-Ichi,Fujii, Kohei,Nishiyama, Hisao
-
supporting information
p. 601 - 605
(2013/03/13)
-
- Ruthenium-catalyzed three-component coupling via hydrative conjugate addition of alkynes to alkenes: One-pot synthesis of 1,4-dicarbonyl compounds
-
A catalytic three-way rendezvous: Terminal alkynes undergo metal vinylidene formation, anti-Markovnikov hydration to give a metal acyl complex, and conjugate addition to produce synthetically useful 1,4-dicarbonyl compounds under ruthenium catalysis. This one-pot three-component coupling reaction is a useful platform for further exploration in alkyne functionalization.
- Chen, Yiyun,Park, Sung Hwan,Lee, Chung Whan,Lee, Chulbom
-
supporting information; experimental part
p. 2000 - 2004
(2011/11/07)
-
- 1, 4-addition of terminal alkynes to conjugated enones in water using green catalyst bis[(l)prolinato-N,O]Zn-An environmentally benign protocol
-
An easy, low cost, and green procedure is proposed for the 1, 4-addition of terminal alkynes to conjugated enones in water as a sole medium using easily accessible Zn[(l)Proline]2. This protocol has advantages of high yield, mild reaction condi
- Kidwai, Mazaahir,Jain, Arti,Bhardwaj, Saurav
-
experimental part
p. 183 - 190
(2011/10/05)
-
- A homogeneous, recyclable polymer support for rh(I)-catalyzed c-c bond formation
-
A robust and practical polymer-supported, homogeneous, recyclable biphephos rhodium(I) catalyst has been developed for C-C bond formation reactions. Control of polymer molecular weight allowed tuning of the polymer solubility such that the polymer-supported catalyst is soluble in nonpolar solvents and insoluble in polar solvents. Using the supported rhodium catalysts, addition of aryl and vinylboronic acids to the electrophiles such as enones, aldehydes, N-sulfonyl aldimines, and alkynes occurs smoothly to provide products in high yields. Additions of terminal alkynes to enones and industrially relevant hydroformylation reactions have also been successfully carried out. Studies show that the leaching of Rh from the polymer support is low and catalyst recycle can be achieved by simple precipitation and filtration.
- Jana, Ranjan,Tunge, Jon A.
-
experimental part
p. 8376 - 8385
(2011/12/04)
-
- Palladium-catalyzed 1,4-addition of terminal alkynes to unsaturated carbonyl compounds promoted by electron-rich ligands
-
The efficient palladium-catalyzed conjugate addition of terminal alkynes to α,β-unsaturated carbonyl compounds has been developed using electron-rich ligands, producing the corresponding γ,δ-alkynyl ketone and γ,δ-alkynyl esters in good yields. The Royal Society of Chemistry.
- Zhou, Lei,Chen, Liang,Skouta, Rachid,Jiang, Huan-Feng,Li, Chao-Jun
-
scheme or table
p. 2969 - 2977
(2009/02/03)
-
- Ruthenium/halide catalytic system for C-C bond forming reaction between alkynes and unsaturated carbonyl compounds
-
A ruthenium complex [triruthenium dodecacarbonyl, Ru3(CO) 12] in the presence of bis(triphenylphosphine)iminium chloride ([PPN]Cl) catalyzes the conjugate addition of terminal alkynes to alkyl acrylates to give high yields of γ,δ-alkynyl esters. On the other hand, the linear codimerization reaction of terminal alkynes with alkyl acrylates proceeds in the presence of a catalytic amount of Ru 3(CO)12 and lithium iodide to give the corresponding conjugate dienes. These two different types of catalytic carbon-carbon bond forming reactions are controlled only by the nature of halide ions, either a chloride or an iodide, with other conditions being kept almost the same.
- Nishimura, Takahiro,Washitake, Yosuke,Uemura, Sakae
-
p. 2563 - 2571
(2008/09/19)
-
- Synthesis and pyrolytic and kinetic behaviour of β,δ′-dioxo-stabilised phosphorus ylides: Convenient preparation of γ,δ-alkynyl ketones and 2,3-functionalised butadienes
-
Both ketone- and ester-stabilised phosphorus ylides undergo Michael addition to vinyl ketones to give the β,δ′-dioxo ylides 3 and 5, respectively, although in the latter case careful temperature control is required to avoid an undesired side-reaction. Under conditions of flash vacuum pyrolysis at 650 °C the ylides 3 generally undergo Ph3PO extrusion to afford the γ,δ-alkynyl ketones 14, although these are found to partly undergo a secondary fragmentation. In contrast, the ylides 5 react under the same conditions to give the synthetically useful 1,3-dienes 20 by way of cyclobutenes. Rate constants for the reaction of selected ylides 3 and 5 are reported. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
- Aitken, R. Alan,Al-Awadi, Nouria A.,Balkovich, Mark E.,Bestmann, Hans Juergen,Clem, Oliver,Gibson, Scott,Gross, Andreas,Kumar, Ajith,Roeder, Thomas
-
p. 840 - 847
(2007/10/03)
-
- Stereoselective synthesis of 2-methylenepyrrolizidines by tandem cyclization of N-propargylaminyl radicals
-
Tandem cyclization of N-propargylaminyl radicals, generated by N-chlorination of (E)-alk-4-enylamines 2a-d and 2f followed by treatment with tributyltin radical, afforded 2-methylenepyrrolizidines 3a-d and 3f in a highly stereoselective manner. A similar
- Hasegawa, Hikaru,Senboku, Hisanori,Kajizuka, Yoshinori,Orito, Kazuhiko,Tokuda, Masao
-
p. 827 - 832
(2007/10/03)
-
- Ir-catalyzed substitution of propargylic-type esters with enoxysilanes
-
Propargylic-type acetates react readily with enoxysilanes in the presence of 1 mol % of [Ir(cod){P(OPh)3}2]OTf activated preliminarily with molecular H2 to give β-alkynyl ketones in high to excellent yields. Substitution a
- Matsuda, Isamu,Komori, Ken-ichi,Itoh, Kenji
-
p. 9072 - 9073
(2007/10/03)
-
- Michael additions of carbonucleophiles to butenone catalyzed by the non- hydride [Ru(O2CH)(CO)2(PPH3)]2 complex
-
[Ru(μ-O2CH)(CO)2(PPh3)]2 in acetonitrile is an efficient catalyst precursor for the Michael addition of soft carbonucleophiles to butenone. The utilization of terminal alkynes as donors makes possible the selective formation of γ,δ-ynones.
- Picquet,Bruneau,Dixneuf
-
p. 3937 - 3948
(2007/10/03)
-
- Sequential epoxide fragmentation/radical cyclizations mediated by samarium(II) iodide
-
A sequential reductive coupling process promoted by samarium(II) iodide is described. Cascade epoxide ring opening and two sequential radical cyclizations lead to a variety of bicyclo[m.n.0] systems as mixtures of diastereomers.
- Molander, Gary A.,Del Pozo Losada, Carlos
-
p. 5819 - 5832
(2007/10/03)
-
- New anionic cyclization of 4- and 5-alkynylamines: Synthesis of 2-Benzylidene pyrrolidines and piperidines
-
Treatment of 4- and 5-alkynylamines with 0.5-1.2 equiv. of butyllithium brought about a facile anionic cyclization, giving the corresponding enamine pyrrolidines and piperidines having an exo double bond in high yields. Treatment of 4-alkynamides with lit
- Tokuda, Masao,Fujita, Hirotake,Nitta, Makoto,Suginome, Hiroshi
-
p. 385 - 395
(2007/10/02)
-
- NOVEL VINYL KETONE - ACETYLENE CROSS-COUPLING CATALYZED BY RhCl(PMe3)3
-
RhCl(PMe3)3 is an effective catalyst of cross-coupling of vinyl ketones with terminal acetylenes to form γ,δ-acetylenic ketones.
- Nikishin, Gennady I.,Kovalev, Igor P.
-
p. 7063 - 7064
(2007/10/02)
-
- NEW FACILE SYNTHESIS OF SUBSTITUTED 2-BENZYLIDENEPYRROLIDINES BY THE ANIONIC CYCLIZATION OF δ-ALKYNYLAMINES
-
Treatment of δ-alkynylamines with butyllithium or lithium aluminum hydride brought about a facile anionic cyclization, giving high yields of the corresponding enamine pyrrolidines having an exo double bound.
- Tokuda, Masao,Fujita, Hirotake,Suginome, Hiroshi
-
p. 5353 - 5356
(2007/10/02)
-