- A straightforward, efficient and versatile preparation of propargylic alcohols from 1-alkynes and aldehydes via GaI3 and amine
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The straightforward additions of 1-alkynes to aldehydes in the presence of GaI3 and an amine give propargylic alcohol in moderate to high yields.
- Han,Huang
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Read Online
- Organocatalytic alkynylation of aldehydes and ketones under phase-transfer catalytic conditions
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We developed alkynylations of various aldehydes and ketones under practical phase-transfer conditions at room temperature. The straightforward methodology combines one-pot synthesis and simple workup with good to excellent yields for propargylic alcohols derived from aliphatic aldehydes and ketones. Even aromatic aldehydes and ketones, could be transformed to the corresponding propargylic alcohols in somewhat lower yields. The yield depending on the amount of PT catalyst and NaOH concentration was also determined. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).
- Weil, Torsten,Schreiner, Peter R.
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Read Online
- Visible Light-Induced Reductive Alkynylation of Aldehydes by Umpolung Approach
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Reductive alkynylation of aldehydes by the Umpolung approach was developed using a photoredox catalyst under blue LED irradiation. Ketyl radicals, generated by single-electron reduction of aldehydes through proton-coupled electron transfer (PCET), reacted with electrophilic alkynylsulfones. Sterically demanding bulky aldehydes reacted smoothly under the Umpolung reaction conditions. Moreover, the alkynylation proceeded chemoselectively with an aryl aldehyde group in the presence of other carbonyl groups including an aliphatic aldehyde group.
- Tanaka, Ibuki,Sawamura, Masaya,Shimizu, Yohei
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supporting information
p. 520 - 524
(2022/01/20)
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- Atom-Economic Synthesis of Highly Functionalized Bridged Ring Systems Initiated by Ring Expansion of Indene-1,3-dione
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An atom economic procedure for the regioselective synthesis of bridged seven-membered-ring compounds from simple reactants such as ynones and indene-1,3-dione has been developed. This process was realized through the one-pot reactions of ring-expansion of
- Mu, Yuanyang,Yao, Qiyi,Yin, Liqiang,Fu, Siyi,Wang, Mengdan,Yuan, Yang,Kong, Lingkai,Li, Yanzhong
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p. 6755 - 6764
(2021/05/06)
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- Straightforward Stereoselective Synthesis of Seven-Membered Oxa-Bridged Rings through in Situ Generated Cycloheptenol Derivatives
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An iodine-mediated stereoselective synthesis of seven-membered oxa-bridged rings via in situ generated cycloheptenols was reported. This process was realized through the combination of C-C σ-bond cleavage and C-O bond-forming reactions in a one-pot fashion from simple and easily accessible raw materials. The formation of carbon radicals initiated by I2 was the key to the reaction.
- Wang, Mengdan,Yin, Liqiang,Cheng, Lu,Yang, Yajie,Li, Yanzhong
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p. 12956 - 12963
(2021/09/13)
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- Selective Insertion of Alkynes into C-C σ Bonds of Indolin-2-ones: Transition-Metal-Free Ring Expansion Reactions to Seven-Membered-Ring Benzolactams or Chromone Derivatives
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An unprecedented ring expansion reaction of indolin-2-ones with alkynyl ketones under transition-metal-free conditions has been developed. Base-promoted selective cleavage of a C-C σ bond of the amide is the key in this process, which provides a straightf
- Wang, Mengdan,Yang, Yajie,Song, Bo,Yin, Liqiang,Yan, Shuhui,Li, Yanzhong
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supporting information
p. 155 - 159
(2020/01/03)
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- HighlyZ-selective synthesis of 1,3-oxathiol-2-ylidenes and 4-methylene-oxazolidine-2-thionesviaatom-specific 5-exo-digcyclization of propargyl alcohol with isothiocyanate
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DBU mediated 5-exo-digcyclization of isothiocyanate and propargyl alcohol leading to valuable heterocyclic compounds has been accomplished. The different modes of nucleophilicity (eitherS-selective orN-selective) of isothiocyanates were found to depend on
- Antony Savarimuthu, S.,Augustine Thomas, S.,Bera, Mrinal K.,Gandhi, Thirumanavelan,Leo Prakash, D. G.
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supporting information
p. 3552 - 3562
(2020/05/25)
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- DBU-Catalyzed Rearrangement of Secondary Propargylic Alcohols: An Efficient and Cost-Effective Route to Chalcone Derivatives
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A 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed rearrangement of diarylated secondary propargylic alcohols to give α,β-unsaturated carbonyl compounds has been developed. The typical 1,3-transposition of oxy functionality, characteristic of Mayer-Schuster rearrangements, is not observed in this case. A broad substrate scope, functional-group tolerance, operational simplicity, complete atom economy, and excellent yields are among the prominent features of the reaction. Additionally, the photophysical properties and crystal-structure-packing behavior of selected compounds were investigated and found to be of interest.
- De, Rimpa,Savarimuthu, Antony,Ballav, Tamal,Singh, Pijush,Nanda, Jayanta,Hasija, Avantika,Chopra, Deepak,Bera, Mrinal K.
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supporting information
p. 1587 - 1592
(2020/08/28)
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- Transition-metal-free C-C σ-bond activation of α-aryl ketones and subsequent Zn-catalyzed intramolecular cyclization: synthesis of tetrasubstituted furans
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A highly atom-economical protocol for the synthesis of tetrasubstituted furans has been developed. This process is realized through the tandem reactions of Cs2CO3 promoted C-C σ-bond activation of α-aryl ketones followed by Zn-cataly
- Yuan, Yang,Tan, Hailu,Kong, Lingkai,Zheng, Zhong,Xu, Murong,Huang, Jiaqi,Li, Yanzhong
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p. 2725 - 2733
(2019/03/12)
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- Phosphorous acid promoted isomerization of propargyl alcohols to α,β-unsaturated carbonyl compounds
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A metal-free and two-phase protocol for the Meyer-Schuster isomerization of propargyl alcohols to the corresponding α,β-unsaturated carbonyl compounds has been achieved in the presence of stoichiometric phosphorous acid aqueous solution, which produces the desired products in high yields with excellent stereoselectivity. Compared with the traditional methods, the procedure features broad scope of the substrates, mild conditions, and easy separation, providing an appealing alternative to the Meyer-Schuster reaction.
- Gan, Xiaotang,Fu, Zuqi,Liu,Yan, Yani,Chen, Chao,Zhou, Yongbo,Dong, Jianyu
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supporting information
(2019/07/12)
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- Cascade and Effective Syntheses of Functionalized Tellurophenes
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A one-pot and transition-metal-catalyst-free synthetic strategy to construct functionalized tellurophenes has been developed. Substituted 1,1-dibromo-1-en-3-ynes are smoothly converted to tellurophenes with telluride salts in high yield via a series of cascade reactions through reductive debromination, hydrotelluration, nucleophilic cyclization, and aromatization. Close inspection of the results clearly showed that the reactivity of in situ prepared telluride salts are significantly influenced by the polarity of the solvent system and the electronic nature of the substituent on the enyne substrate. This method reports the first direct synthesis of 3-aryltellurophenes in high yields at room temperature. This novel reaction strategy is also found to be a promising synthetic method for multisubstituted tellurophenes and selenophenes.
- Karapala, Vamsi Krishna,Shih, Hong-Pin,Han, Chien-Chung
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supporting information
p. 1550 - 1554
(2018/03/23)
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- Transition-Metal-Free Ring Expansion Reactions of Indene-1,3-dione: Synthesis of Functionalized Benzoannulated Seven-Membered Ring Compounds
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A novel ring expansion reaction of indene-1,3-dione with alkynyl ketones under transition-metal-free conditions has been developed. This process offers an efficient and direct way to synthesize benzoannulated seven-membered rings or fused-ring compounds t
- Yao, Qiyi,Kong, Lingkai,Wang, Mengdan,Yuan, Yang,Sun, Ruizhuo,Li, Yanzhong
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supporting information
p. 1744 - 1747
(2018/04/14)
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- Gold(I)-Catalyzed [2 + 2 + 2] Cyclotrimerization of 1,3-Diarylpropargyl Acetals
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A gold-nitrone catalyzed [2 + 2 + 2] cyclotrimerization of 1,3-diarylpropargyl acetals into cyclohexylidene products (up to 74% yield) is reported. The trimerization is proposed to proceed through allenic intermediates via gold-catalyzed 1,3-alkoxy rearra
- Jónsson, Helgi Freyr,Evjen, Sigvart,Fiksdahl, Anne
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supporting information
p. 2202 - 2205
(2017/05/12)
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- Highly Efficient Synthesis of Multi-Substituted Allenes from Propargyl Acetates and Organoaluminum Reagents Mediated by Palladium
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A simple and mild catalytic S N 2′ substitution reaction of propargyl acetates with organoaluminum reagents is reported. The S N 2′ substitution reaction of propargyl acetates with organoaluminum reagents mediated by Pd(PhP 3) 2 Cl 2 (1 mol%)/PPh 3 (2 mol%)/K 2 CO 3 in tetrahydrofuran at 60 °C for 3-4 hours afforded the corresponding multi-substituted allenes in good yields (up to 94%) with high selectivities (up to 99%). The process was simple and easily performed, which offers an efficient method to synthesize the multi-substituted allene derivatives.
- Zhang, Zhen,Shao, Xuebei,Zhang, Gang,Li, Qinghan,Li, Xinying
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p. 3643 - 3653
(2017/08/16)
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- Expedient synthesis of new cinnoline diones by Ru-catalyzed regioselective unexpected deoxygenation-oxidative annulation of propargyl alcohols with phthalazinones and pyridazinones
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Ruthenium-catalyzed simple, cascade and one-pot synthesis of cinnoline-fused diones has been carried out by the C-H activation of phthalazinones/pyridazinones accomplished by the unusual deoxygenation of propargyl alcohols. The bond selectivity is accredited to the traceless directing nature of the hydroxyl group of propargyl alcohol. A sequential C-H activation, insertion and deoxy-oxidative annulation has been proposed based on the preliminary mechanistic study.
- Rajkumar, Subramani,Antony Savarimuthu,Senthil Kumaran, Rajendran,Nagaraja,Gandhi, Thirumanavelan
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supporting information
p. 2509 - 2512
(2016/02/12)
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- Synthesis of 2-Sulfenylindenones via One-Pot Tandem Meyer-Schuster Rearrangement and Radical Cyclization of Arylpropynols with Disulfides
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A tandem annulation of arylpropynols with disulfides has been developed for the synthesis of 2-sulfenylindenone derivatives. The reaction pathway involves one-pot tandem Meyer-Schuster rearrangement of arylpropynols and successive radical cyclization with disulfides. Various arylpropynols and disulfides with a number of functional groups are compatible in this reaction that affords the corresponding 2-sulfenylindenones in moderate to good yields.
- Zhang, Xing-Song,Jiao, Jun-Ying,Zhang, Xiao-Hong,Hu, Bo-Lun,Zhang, Xing-Guo
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p. 5710 - 5716
(2016/07/13)
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- Insertion of Isolated Alkynes into Carbon–Carbon σ-Bonds of Unstrained Cyclic β-Ketoesters via Transition-Metal-Free Tandem Reactions: Synthesis of Medium-Sized Ring Compounds
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The transition-metal-free insertion of isolated alkynes into carbon–carbon σ-bonds of unstrained cyclic β-dicarbonyl compounds has been reported. These tandem reactions offer an efficient synthesis of medium-sized ring or fused-ring compounds through ring expansion. The methodology has the potential to be widely used throughout organic synthesis due to the easily accessible starting materials and mild reaction conditions.
- Zhou, Yuanyuan,Tao, Xianghua,Yao, Qiyi,Zhao, Yulei,Li, Yanzhong
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supporting information
p. 17936 - 17939
(2016/12/16)
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- Addition of terminal alkynes to α-ketone esters to synthesize α-tertiary-hydroxy esters promoted by zinc and an alkyl halide
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A convenient method to synthesize various α-tertiary-hydroxy esters at room temperature has been developed. This method uses the readily available and inexpensive Zn powder in combination with an alkyl halide to promote the addition of alkynes to α-ketone
- Zhang, Wen,Cao, Yuan,Chen, Wei,Zhao, Gang,Pu, Lin
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supporting information
p. 6430 - 6432
(2015/11/16)
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- Modulation of silver-titania nanoparticles on polymethylhydrosiloxane-based semi-interpenetrating networks for catalytic alkynylation of trifluoromethyl ketones and aromatic aldehydes in water
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In this work, we have developed a new approach to monodispersed hybrid Ag@TiO2 nanocomposites using a titanium-promoted cross-linking reduction in the Si-H functional material, polymethylhydrosiloxane (PMHS)-based semi-interpenetrating networks
- Wang, Hu,Yang, Ke-Fang,Li, Li,Bai, Ying,Zheng, Zhan-Jiang,Zhang, Wei-Qiang,Gao, Zi-Wei,Xu, Li-Wen
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p. 580 - 591
(2014/03/21)
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- Direct synthesis of 4-fluoroisoxazoles through gold-catalyzed cascade cyclization-fluorination of 2-alkynone O-methyl oximes
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A tandem protocol for the synthesis of fluorinated isoxazoles has been developed via catalytic intramolecular cyclizations of 2-alkynone O-methyl oximes and ensuing fluorination. The reactions proceed smoothly at room temperature in the presence of 5 mol
- Jeong, Yunkyung,Kim, Bom-I,Lee, Jae Kyun,Ryu, Jae-Sang
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p. 6444 - 6455
(2014/08/05)
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- Synthesis of quinazoline based chiral ligands and application in the enantioselective addition of phenylacetylene to aldehydes
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Five novel 4-phenylquinazolinols were synthesised in three steps. Their application as ligands in the titanium tetraisopropoxide promoted catalytic enantioselective addition of phenylacetylene to a variety of aldehydes gave propargylic alcohols. Under the
- Karakaya, Idris,Karabuga, Semistan,Altundas, Ramazan,Ulukanli, Sabri
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supporting information
p. 8385 - 8388
(2015/03/05)
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- Redox and Lewis acid relay catalysis: A titanocene/zinc catalytic platform in the development of multicomponent coupling reactions
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A titanocene-catalyzed multicomponent coupling is described herein. Using catalytic titanocene, phosphine, and zinc dust, zinc acetylides can be generated from the corresponding iodoalkynes to affect sequential nucleophilic additions to aromatic aldehydes. The intermediate propargylic alkoxides are trapped in situ with acetic anhydride, which are susceptible to a second nucleophilic displacement upon treatment with a variety of electron-rich species, including acetylides, allyl silanes, electron-rich aromatics, silyl enol ethers, and silyl ketene acetals. Additionally, employing cyclopropane carboxaldehydes led to ring-opened products resulting from iodine incorporation. Taken together, these results form the basis for a new mode of three-component coupling reactions, which allows for rapid access to value added products in a single synthetic operation.
- Gianino, Joseph B.,Campos, Catherine A.,Lepore, Antonio J.,Pinkerton, David M.,Ashfeld, Brandon L.
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p. 12083 - 12095
(2015/02/19)
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- A mild and efficient AgSbF6-catalyzed synthesis of fully substituted pyrroles through a sequential propargylation/amination/ cycloisomerization reaction
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Development of an efficient synthesis of fully substituted pyrroles via a sequential propargylation/amination/cycloisomerization was accomplished using AgSbF6 as a catalyst. The one-pot three-component reaction of propargylic alcohols, 1,3-dica
- Gujarathi, Satheesh,Liu, Xingui,Song, Lin,Hendrickson, Howard,Zheng, Guangrong
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p. 5267 - 5273
(2014/07/08)
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- A mild and efficient AgSbF6-catalyzed synthesis of fully substituted pyrroles through a sequential propargylation/amination/cycloisomerization reaction
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Development of an efficient synthesis of fully substituted pyrroles via a sequential propargylation/amination/cycloisomerization was accomplished using AgSbF6as a catalyst. The one-pot three-component reaction of propargylic alcohols, 1,3-dicar
- Gujarathi, Satheesh,Liu, Xingui,Song, Lin,Hendrickson, Howard,Zheng, Guangrong
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p. 5267 - 5273
(2014/12/10)
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- Catalytic asymmetric enyne addition to aldehdyes and Rh(I)-catalyzed stereoselective domino Pauson-Khand/[4 + 2] cycloaddition
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The 1,1′-bi-2-naphthol-ZnEt2-Ti(OiPr) 4-Cy2NH system is found to catalyze the 1,3-enyne addition to aliphatic aldehydes as well as other aldehydes at room temperature with 75-96% yield and 82-97% ee. This system is also broadly applicable for the highly enantioselective reaction of other alkyl-, aryl-, and silylalkynes with structurally diverse aldehydes. The propargylic alcohols prepared from the catalytic asymmetric enyne addition to aliphatic aldehydes are used to prepare a series of optically active trienynes. In the presence of a catalytic amount of [RhCl(CO)2]2 and 1 atm of CO, the optically active trienynes undergo highly stereoselective domino Pauson-Khand/[4 + 2] cycloaddition to generate optically active multicyclic products. The Rh(I) catalyst is also found to catalyze the coupling of a diyne with CO followed by [4 + 2] cycloaddition to generate an optically active multicyclic product. These transformations are potentially useful for the asymmetric synthesis of polyquinanes containing a quaternary chiral carbon center.
- Chen, Wei,Tay, Jia-Hui,Ying, Jun,Yu, Xiao-Qi,Pu, Lin
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p. 2256 - 2265
(2013/04/24)
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- Synthesis and biological evaluation of 3-amino-2-pyrones as selective cyclooxygenase-1 (COX-1) inhibitors
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A group of 3-amino-2-pyrones were synthesized and their biological activities were evaluated for inhibiting cyclooxygenase (COX) activity. This study has led to the identification of COX-1-selective inhibitors. Among the tested compounds, the compound 5j exhibited the most potent COX-1 inhibitory activity (IC50 = 19.32 μg/mL) and COX-1 selectivity index (SI = 41.98).
- Chu, Xue-Ping,Zhou, Qing-Fa,Zhao, Shen,Ge, Fei-Fei,Fu, Mian,Chen, Jia-Peng,Lu, Tao
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p. 120 - 122
(2013/06/27)
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- Condensation of propargylic alcohols with N-methylcarbazole and carbazole in [bmim]PF6 ionic liquid; Synthesis of novel dipropargylic carbazoles using TfOH or Bi(NO3)3·5H2O as catalyst
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A series of doubly-propargylated N-methylcarbazole and carbazole derivatives were synthesized in good to excellent isolated yields in (bmim)PF6 using triflic acid (10 mol %). The use of bismuth nitrate (20 mol %) instead of triflic acid allowed stepwise propargylation employing two different propargylic alcohols, to prepare mixed bis-propargylated carbazoles. Simple product isolation, mild reaction conditions, and repeated recycling and reuse of (bmim)PF6 are added advantages of this IL-mediated synthetic method.
- Kumar, G.G.K.S. Narayana,Laali, Kenneth K.
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supporting information
p. 965 - 969
(2013/03/13)
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- Heteropolyacid-catalyzed direct deoxygenation of propargyl and allyl alcohols
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The combination of H3[PW12O40] ?nH2O (1 mol %) and Et3SiH led to the direct catalytic deoxygenation of propargyl alcohols, in which proper solvent selection Cl(CH2)2Cl vs CF3CH2OH was the key to obtaining better product yields. Under similar conditions, the deoxygenation of allyl alcohols proceeded to give thermodynamically stable alkenes with migration of the double bonds in good yields.
- Egi, Masahiro,Kawai, Takuya,Umemura, Megumi,Akai, Shuji
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experimental part
p. 7092 - 7097
(2012/10/07)
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- A convenient approach to β-heteroarylated (C-N bond) ketones from Cs2CO3 promoted reaction between propargyl alcohols and nitrogen-heterocycles
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An efficient and direct approach to β-heteroarylated (C-N bond) ketones is demonstrated. Base promoted redox isomerization of propargyl alcohol to α,β-unsaturated ketone followed by conjugate addition to NH-heteroarenes affords a wide range of β-heteroarylated ketones in good to excellent yields. Aryl, heteroaryl, alkyl C(sp), and terminal alkynes containing unactivated propargyl alcohols effectively undergo redox-isomerization conjugate addition (RICA) with NH-heteroarenes. Reaction of 3-substituted pyrazoles or indazole with propargyl alcohols enables highly regioselective products. A diverse range of NH-bearing nucleophiles such as: pyrazoles, imidazole, triazoles, pyrrole, indoles and aniline participate in this reaction and deliver the corresponding β-heteroarylated ketones.
- Bhanuchandra,Kuram, Malleswara Rao,Sahoo, Akhila K.
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experimental part
p. 3538 - 3555
(2012/05/20)
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- Tandem amination/cycloisomerization of aryl propargylic alcohols with 2-aminopyridines as an expedient route to imidazo[1,2-a]pyridines
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A new tandem route leading to imidazo[1,2-a]pyridines has been explored through the direct amination of aryl propargylic alcohols with 2-aminopyridines and their subsequent intramolecular cycloisomerization. A ZnCl2/CuCl system has been develop
- Liu, Ping,Deng, Chun-Lin,Lei, Xinsheng,Lin, Guo-Qiang
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experimental part
p. 7308 - 7316
(2012/01/06)
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- TBuOLi-mediated alkynylation of aldehydes
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The lithium tert-butoxide reagent was found to promote the addition of terminal aromatic alkynes to various aromatic aldehydes. This reaction was efficiently carried out in anhydrous dimethylformamide at room temperature in air for 50min, and the correspo
- Li, Chuanbin,Li, Xiaolong,Meng, Xu,Wang, Tiansheng,Li, Jihui,Chen, Baohua
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experimental part
p. 1208 - 1217
(2011/05/04)
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- Solvent-free synthesis of propargylic alcohols using zno as a new and reusable catalyst by direct addition of alkynes to aldehydes
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Under solvent-free conditions, the synthesis of propargylic alcohols by direct addition of terminal alkynes to aldehydes promoted by ZnO as a novel, commercially, and cheap catalyst is described. Furthermore, the catalyst can be reused for several times w
- Hosseini-Sarvari, Mona,Mardaneh, Zahra
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experimental part
p. 4297 - 4303
(2012/02/16)
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- Three component tandem reactions involving protected 2-amino indoles, disubstituted propargyl alcohols, and I2/ICl: Iodo-reactant controlled synthesis of dihydro-α-carbolines and α-carbolines via iodo-cyclization/iodo-cycloelimination
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Two simple, highly efficient three component tandem reactions for the synthesis of diversified Na Nb di-carbamate-4,9-dihydro-3- iodo-α-carbolines and Na-carbamate-3-iodo-α-carbolines have been described. The strategy invo
- Sharma, Sudhir K.,Gupta, Sahaj,Saifuddin, Mohammad,Mandadapu, Anil K.,Agarwal, Piyush K.,Gauniyal, Harsh M.,Kundu, Bijoy
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supporting information; experimental part
p. 65 - 68
(2011/02/26)
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- Electrophilic carbocyclization of aryl propargylic alcohols: A facile synthesis of diiodinated carbocycles and heterocycles
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Diiodinated carbocycles and oxygen heterocycles can be readily synthesized by electrophilic carbocyclization of aryl propargylic alcohols in moderate to good yields under mild conditions. The resulting diiodide can be further exploited by subsequent oxidi
- Zhu, Hai-Tao,Ji, Ke-Gong,Yang, Fang,Wang, Li-Jing,Zhao, Shu-Chun,Ali, Shaukat,Liu, Xue-Yuan,Liang, Yong-Min
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supporting information; experimental part
p. 684 - 687
(2011/05/03)
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- Synthesis of phosphonylated and thiolated indenones by manganese(III)- mediated addition of phosphorus- and sulfur-centered radicals to 1,3-diarylpropynones
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Phosphorus- or sulfur-centered radicals generated from the reaction of manganese(III) acetate with dialkyl phosphonates or arylthiols undergo selective additions to conjugated alkynes followed by cyclization and rearomatization to afford 2-phosphonyl- or
- Zhou, Jun,Zhang, Guang-Liang,Zou, Jian-Ping,Zhang, Wei
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supporting information; experimental part
p. 3412 - 3415
(2011/09/12)
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- A new and general one-pot synthesis of propargyl alcohols from esters
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Intermediates easily prepared by partial reduction of various esters with LDBBA as a reducing agent smoothly react with lithium acetylides to give propargyl alcohols, without isolation of partial reduction intermediates, in good yields (73-83%).
- Chae, Min Jung,Jeon, Ah Ram,Livinghouse, Tom,An, Duk Keun
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experimental part
p. 3281 - 3283
(2011/05/05)
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- Enantioselective alkynylation of aldehydes with 1-haloalkynes catalyzed by tethered bis(8-quinolinato) chromium complex
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The first example of Cr-catalyzed asymmetric alkynylation of aldehydes with 1-iodo- and 1-bromoalkynes was developed. The use of tethered bis(8-quinolinato) chromium catalyst (3 mol %) allowed preparation of enantioenriched propargyl alcohols with good yields and enantioselectivities up to 92% ee. 1-Bromoalkynes can be activated by the introduction of a cobalt porphine cocatalyst, which enables shorter reaction times without any loss of enantiocontrol.
- Usanov, Dmitry L.,Yamamoto, Hisashi
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p. 1286 - 1289
(2011/04/16)
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- Synthesis of phosphine-ligated zinc acetylide dimers: Enhanced reactivity in carbonyl additions
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Phosphine-ligated dinuclear zinc acetylides effectively promote the alkynylation of carbonyl derivatives. Good to excellent yields (46-91%) of the corresponding propargylic alcohols were obtained from a wide range of substrates. Crystallographic evidence
- Wilson, Erin E.,Oliver, Allen G.,Hughes, Russell P.,Ashfeld, Brandon L.
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experimental part
p. 5214 - 5221
(2011/11/13)
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- Au(PPh3)Cl-AgSbF6-catalyzed rearrangement of propargylic 1,3-dithianes: Formation of 8-membered 1,3-bisthio-substituted cyclic allenes
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Au(PPh3)Cl-AgSbF6-catalyzed rearrangement of propargylic 1,3-dithiane leads to the formation of 8-membered dithio-substituted cyclic allenes, which are remarkably stable. The Royal Society of Chemistry 2009.
- Zhao, Xia,Zhong, Zhenzhen,Peng, Lingling,Zhang, Wenxiong,Wang, Jianb
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supporting information; experimental part
p. 2535 - 2537
(2009/09/30)
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- 3,3′-anisyl-substituted BINOL, H4BINOL, and H 8BINOL ligands: Asymmetric synthesis of diverse propargylic alcohols and their ring-closing metathesis to chiral cycloalkenes
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(Chemical Equation Presented) A series of optically active BINOL, H 4BINOL, and H8BINOL derivatives were prepared. These compounds in combination with ZnEt2 and Ti(OiPr) 4 were used to catalyze the asymmetric reaction of alkynes with aldehydes to generate chiral propargylic alcohols at room temperature. Through this comparative study, a 3,3′-bisanisyl-substituted H8BINOL (S)-7 was found to be a generally enantioselective catalyst for the reaction of structurally diverse terminal alkynes with a variety of aldehydes. It catalyzed the reactions of alkyl propiolates with 88-99% ee; the reactions of phenylacetylene with 81-87% ee; the reactions of 4-phenyl-1-butyne, an alkyl alkyne, with 77-89% ee; and the reactions of trimethylsilylacetylene with 92-97% ee. The optically active propargylic alcohols generated from this catalytic asymmetric alkyne addition were observed to undergo efficient ring-closing-metathesis (RCM) reaction in the presence of the Grubbs II catalyst to produce chiral cycloalkenes. It was further found that some of the chiral propargylic alcohols underwent a highly chemoselective tandem RCM hydrogenation reaction with retention of the enantiomeric purity. 2009 American Chemical Society.
- Yue, Yang,Turlington, Mark,Yu, Xiao-Qi,Pu, Lin
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supporting information; experimental part
p. 8681 - 8689
(2009/12/30)
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- Catalytic enantioselective addition of terminal alkynes to aromatic aldehydes using zinc-hydroxyamide complexes
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A mandelamide ligand, derived from (S)-mandelic acid and (S)-phenylethanamine, catalyzes the addition of aryl-, alkyl- and silyl-alkynylzinc reagents to aromatic and heteroaromatic aldehydes with good yields and good to high enantioselectivities.
- Blay, Gonzalo,Cardona, Luz,Fernandez, Isabel,Marco-Aleixandre, Alicia,Munoz, M. Carmen,Pedro, Jose R.
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scheme or table
p. 4301 - 4308
(2009/12/05)
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- NbCl5 mediated deprotection of methoxy methyl ether
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An efficient cleavage of methoxy methyl ether using NbCl5 is described. This protocol works efficiently with MOM ethers of alkyl, allyl, propargyl, benzyl alcohol and phenol derivatives. MOM esters are also found to be effectively cleaved under the present conditions.
- Yadav,Ganganna,Bhunia, Dinesh C.,Srihari
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experimental part
p. 4318 - 4320
(2009/10/26)
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- Unprecedented consecutive, competitive nucleophilic addition to construct densely functionalized propargylic alcohols
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An efficient one-pot process to construct a series of polyfunctionalized propargylic alcohol derivatives from the simple materials without functional protection was investigated. A solution of nBuLi in hexane was added into dry THF by syringe the resulting solution was then maintained at RT for 3 hours. the freshly prepared lithium enolate of acetaldehyde was used directly in the reaction. The nBuLi was added over a period of 30 minutes by syringe to a solution of terminal alkyne in THF at -30°C. The scope and limitations of the reaction was explored by examining other terminal alkynes. A number of different carbonyl-containing substrates were also examined. It was observed that propargylic alcohol derivatives are important synthetic intermediates in organic synthesis.
- Liu, Jie,An, Yan,Wang, Ya-Hui,Jiang, Hai-Ying,Zhang, Yu-Xin,Chen, Zili
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supporting information; experimental part
p. 9131 - 9134
(2009/09/06)
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- Me3Ga-mediated alkynylation of aldehydes
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The trimethylgallium reagent was found to promote the addition of phenylacetylene to various aromatic and aliphatic aldehydes. This reaction was efficiently carried out in anhydrous CH2Cl2 at room temperature under mild conditions an
- Jia, Xuefeng,Yang, Hongwei,Fang, Ling,Zhu, Chengjian
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p. 1370 - 1372
(2008/09/18)
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- Titanium and zirconium benzofuranoxides. Crystal structures and catalytic properties
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Reactions of Ti(OiPr)4 or Zr(OEt)4 with 4 equivalents of 2,3-dihydro-2,2-dimethyl-7-benzofuranol (ddbfoH) in toluene gave neutral complexes that in the solid state are dimers of [Ti(μ-ddbfo) 2(ddbfo)6] and [Zr(ddbfo)3(EtOH)(μ-EtO)] 2 composition. The former could also be conveniently synthesized in a direct reaction of TiCl4 with ddbfoH. This air-stable aryloxo compound was found to initiate living ring-opening polymerization of lactides affording polyesters with narrow molecular weight distribution. It also catalyzed addition of terminal acetylenes to aryl aldehydes. The Royal Society of Chemistry.
- Krauzy-Dziedzic, Katarzyna,Ejfler, Jolanta,Szafert, Slawomir,Sobota, Piotr
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p. 2620 - 2626
(2008/09/20)
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- Catalytic deprotonative functionalization of propargyl silyl ethers with imines
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A metal-free, catalytic C-H functionalization of propargyl silyl ethers with imines using the phosphazene base (t-Bu-P4 base) provides structurally defined multisubstituted pyrroles in modest to excellent yields under mild conditions. A one-pot, three-component reaction using silylated acetylenes, aldehydes, and imines is also presented.
- Naka, Hiroshi,Koseki, Daiki,Kondo, Yoshinori
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supporting information; experimental part
p. 1901 - 1906
(2009/08/07)
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- Siloxyallenes revisited. A useful functional intermediate for the synthesis of (Z)-β-branched Morita-Baylis-Hillman type adducts and (Z)-chalcones
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Siloxyallenes proved to be a useful functional intermediate in the preparation of (Z)-β-branched Morita-Baylis-Hillman type adducts by the reaction of aldehydes with silylacetylenes or siloxypropynes. Various (Z)-chalcones were stereoselectively synthesized from siloxypropynes via siloxyallenes.
- Yoshizawa, Kazuhiro,Shioiri, Takayuki
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p. 6259 - 6286
(2008/02/04)
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- 1,1′-Binaphthyl ligands with bulky 3,3′-tertiaryalkyl substituents for the asymmetric alkyne addition to aromatic aldehydes
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The BINOL ligand (R)-2 that contains bulky 3,3′-tertiaryalkyl groups shows improved catalytic properties over the previously reported 3,3′-substituted BINOL ligands in the asymmetric alkyne addition to aromatic aldehydes. It catalyzes the phenylacetylene
- Wang, Qin,Chen, Shan-Yong,Yu, Xiao-Qi,Pu, Lin
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p. 4422 - 4428
(2008/02/02)
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- Bisoxazolidine-catalyzed enantioselective alkynylation of aldehydes
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A C2-symmetric bisoxazolidine derived from aminoindanol has been successfully applied in the asymmetric alkynylation of aldehydes. The ligand is readily available, has a wide substrate scope, and catalyzes the formation of chiral propargylic alcohols with excellent yields and enantioselectivties. Copyright
- Wolf, Christian,Liu, Shuanglong
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p. 10996 - 10997
(2007/10/03)
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- Synthesis of β-branched Morita-Baylis-Hillman-type adducts from 1,3-diaryl-2-propynyl trimethylsilyl ethers and aldehydes catalyzed by potassium tert-butoxide
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1,3-Diaryl-2-propynyl trimethylsilyl ethers were easy to isomerize into the corresponding siloxyallenes using a catalytic amount of potassium tert-butoxide under very mild conditions. The siloxyallenes reacted in situ with various aldehydes to afford Z-selective β-branched Morita-Baylis-Hillman-type adducts in a one-pot reaction after acid treatment.
- Yoshizawa, Kazuhiro,Shioiri, Takayuki
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p. 757 - 761
(2007/10/03)
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- Facile and convenient synthesis of functionalized propargylic alcohols and amines: An InBr3-Et3N reagent system promotes the alkynylation of aldehydes and N,O- or N,S-acetals
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The use of a novel InBr3-Et3N reagent system to promote the alkynylation of not only a variety of aromatic/heterocyclic or bulky aliphatic aldehydes but also N,O- or N,S-acetals is described. The use of N-silyl-N,O-acetals and 1-alkynes could lead to the direct production of primary propargylic amines in good yields.
- Sakai, Norio,Kanada, Reiko,Hirasawa, Maki,Konakahara, Takeo
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p. 9298 - 9304
(2007/10/03)
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- Phosphine-triggered complete chemo-switch: From efficient aldehyde-alkyne-amine coupling to efficient aldehyde-alkyne coupling in water
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(Chemical Equation Presented) A phosphine ligand served as a remarkable chemo-switch for the silver-catalyzed reaction of alkynes with aldehydes in the presence of amines in water. Exclusive aldehyde-alkyne-amine coupling product was observed in the absen
- Yao, Xiaoquan,Li, Chao-Jun
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p. 4395 - 4398
(2007/10/03)
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