- Stereodivergent Palladium- And Rhodium-Catalyzed Intramolecular Addition of Tosylureas to Allenes: Diastereoselective Synthesis of Tetrahydropyrimidinones
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The intramolecular addition of tosylureas to allenes is highly syn-/anti-diastereoselective when employing a palladium or rhodium-based catalytic system and affords 1,3-cyclic ureas. Under palladium catalysis a range of thermodynamic anti-tetrahydropyrimi
- Breit, Bernhard,Geissler, Arne G. A.,Riesterer, Jasmin R.
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supporting information
p. 9168 - 9172
(2021/12/06)
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- Photoredox propargylation of aldehydes catalytic in titanium
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A practical and effective photoredox propargylation of aldehydes promoted by 10 mol % of [Cp2TiCl2] is presented. No stoichiometric metals or scavengers are used for the process. A catalytic amount of the cheap and simply prepared or
- Calogero, Francesco,Gualandi, Andrea,Di Matteo, Marco,Potenti, Simone,Fermi, Andrea,Bergamini, Giacomo,Cozzi, Pier Giorgio
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p. 7002 - 7009
(2021/05/29)
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- One-Pot γ-Lactonization of Homopropargyl Alcohols via Intramolecular Ketene Trapping
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A one-pot γ-lactonization of homopropargyl alcohols via an alkyne deprotonation/boronation/oxidation sequence has been developed. Oxidation of the generated alkynyl boronate affords the corresponding ketene intermediate, which is trapped by the adjacent hydroxy group to furnish the γ-lactone. We have optimized the conditions as well as examined the substrate scope and synthetic applications of this efficient one-pot lactonization.
- Yamane, Daichi,Tanaka, Haruna,Hirata, Akihiro,Tamura, Yumiko,Takahashi, Daichi,Takahashi, Yusuke,Nagamitsu, Tohru,Ohtawa, Masaki
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supporting information
p. 2831 - 2835
(2021/05/05)
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- Synthesis of vinylic sulfones in aqueous media
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A green method for the sulfination of allenic carbonyl compounds to access a wide variety of vinylic sulfones is developed. This reaction works in aqueous media under very mild conditions. This reaction is atom economic. A wide variety of vinylic sulfones could be obtained in moderate to excellent yields with wide functional group tolerance. The efficiency of this method is demonstrated in some reactions where the desired products can be isolated by filtration.
- Goh, Jeffrey,Maraswami, Manikantha,Loh, Teck-Peng
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supporting information
p. 1060 - 1065
(2021/02/16)
-
- Allenone-Mediated Racemization/Epimerization-Free Peptide Bond Formation and Its Application in Peptide Synthesis
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Allenone has been identified as a highly effective peptide coupling reagent for the first time. The peptide bond was formed with an α-carbonyl vinyl ester as the key intermediate, the formation and subsequent aminolysis of which proceed spontaneously in a racemization-/epimerization-free manner. The allenone coupling reagent not only is effective for the synthesis of simple amides and dipeptides but is also amenable to peptide fragment condensation and solid-phase peptide synthesis (SPPS). The robustness of the allenone-mediated peptide bond formation was showcased incisively by the synthesis of carfilzomib, which involved a rare racemization-/epimerization-free N to C peptide elongation strategy. Furthermore, the successful synthesis of the model difficult peptide ACP (65-74) on a solid support suggested that this method was compatible with SPPS. This method combines the advantages of conventional active esters and coupling reagents, while overcoming the disadvantages of both strategies. Thus, this allenone-mediated peptide bond formation strategy represents a disruptive innovation in peptide synthesis.
- Wang, Penghui,Wang, Xuewei,Wang, Zhengning,Zhao, Junfeng
-
supporting information
p. 10374 - 10381
(2021/07/26)
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- Formal metal-free γ-arylation of 1,3-dicarbonyl compounds: Via an isomerisation/1,4-addition/[3,3]-sigmatropic rearrangement sequence
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A metal-free redox arylation of alkynes with sulfoxides has been developed to provide unconventional access to diverse γ-arylated 1,3-dicarbonyl compounds in an atom-economical manner. Mechanistic studies suggest that a conjugated allenone intermediate was generated in situ, which solves the problem of reactivity and regioselectivity of unsymmetrical dialkyl-substituted internal alkynes and enables the functionalisation of a broad range of substrates bearing electron-withdrawing functional groups. The resulting arylated 1,3-dicarbonyl compounds are versatile and useful building blocks for further functionalisation. This journal is
- Guan, Xi-Dong,Lu, Shi-Chao,Wen, Fu-Qiang
-
supporting information
p. 8964 - 8968
(2021/11/27)
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- One-pot, regioselective synthesis of homopropargyl alcohols using pro-pargyl bromide and carbonyl compound by the mg-mediated reaction under solvent-free conditions
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The elimination of volatile organic solvents in organic synthesis is the most important goal in “Green” chemistry. We report a simple, efficient and facile method for the addition of progargyl bromide to carbonyl compounds using Mg metal as a mediator under solvent-free conditions which could regioselectively generate homopropargyl alcohols efficiently in good to excellent yields. The procedure has advantages such as short reaction time, operationally simple, excellent product yields, high regioselectivity and organic solvent-free.
- Devaramani, Samrat,Li, Shunxi,Ma, Xiaofang,Xu, Daqian,Zhao, Guohu
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supporting information
p. 438 - 442
(2020/04/21)
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- Synthesis, characterization of active Sn(0), and its application in selective propargylation of aldehyde at room temperature in water
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Active Sn(0) particles are synthesized in high yields by the chemical reduction of the blue-black stannous oxide using freshly prepared sodium stannite solution as reducing agent at 40 °C and 60 °C. The Sn(0) particles are characterized using powder XRD, SEM, and DSC. The as-synthesized Sn(0) particles are applied as reagent for the regioselective synthesis of homopropargyl alcohols from propargyl bromide and aldehydes in distilled water at room temperature (in 50%-84% yields). No assistance of heat, microwave, ultrasound, organic co-solvent, co-reagent, or inert atmosphere is required for this reaction. The propargylation reaction is highly chemoselective towards aldehyde over other less electrophilic carbonyl functional groups such as ketone, amide, and carboxylic acid. Our in-house synthesized homopropargyl alcohols can be used to synthesize conjugated 1,3-diynes.
- Chatterjee, Paresh Nath,Paul, Dipankar,Sawkmie, Micky Lanster,Sinha, Arun Kumar,Khatua, Snehadrinarayan
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supporting information
p. 29 - 36
(2019/01/10)
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- Active bismuth mediated allylation of carbonyls/N-tosyl aldimines and propargylation of aldehydes in water
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Abstract: Active bismuth is synthesized by the chemical reduction of bismuth trichloride using freshly prepared sodium stannite solution as the reducing agent at room temperature. The as-synthesized active bismuth is applied as a reagent for the synthesis of homoallyl alcohol/homopropargyl alcohol from allyl bromide/propargyl bromide and carbonyl compounds in water at 50°C. The homoallyl amines are also synthesized from N-tosyl aldimines and allyl bromide using active bismuth reagent in good yields. No assistance of organic co-solvent, co-reagent, phase transfer catalyst or inert atmosphere is required for this reaction. The waste bismuth material obtained after the completion of the organic reaction can be reduced to active bismuth by sodium stannite solution and successfully reused for mediating the allylation of aldehydes. Graphical Abstract:: Synopsis Active bismuth mediated allylation/crotylation of aldehydes is developed in water to get homoallyl alcohols. The method is also applied for the allylation of N-tosyl aldimines and propargylation of aldehydes in water to achieve the homoallyl amines and homopropargyl alcohols, respectively. The reactions do not require the assistance of organic co-solvent, co-reagent, phase transfer catalyst or inert atmosphere.[Figure not available: see fulltext.].
- Sawkmie, Micky Lanster,Paul, Dipankar,Khatua, Snehadrinarayan,Chatterjee, Paresh Nath
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- Synthesis and characterization of nano?zinc wire using a self designed unit galvanic cell in aqueous medium and its reactivity in propargylation of aldehydes
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Electrochemistry is used for propargylation of carbonyls in aqueous ZnCl2 medium. For electrochemical process we designed a unit galvanic cell. ZnCl2 is used as stoichiometric reagent and causes electrochemical deposition of zinc in
- Mondal, Bibhas,Mandal, Siba Prasad,Kundu, Mousumi,Adhikari,Roy, Ujjal Kanti
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supporting information
p. 4669 - 4675
(2019/07/22)
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- A facile lipase-catalyzed KR approach toward enantiomerically enriched homopropargyl alcohols
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Compounds possessing propargylic (prop-2-ynylic) system are very important building blocks for organic chemistry. Among them, preparation of enantiomeric homopropargyl alcohols (but-3-yn-1-ols) constitutes a key-challenge for asymmetric synthesis and thus
- Borowiecki, Pawe?,Dranka, Maciej
-
supporting information
(2019/02/14)
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- A bicyclization reaction with two molecular allenyl ketones and isocyanides: Synthesis of a lactone-containing azaspirocycle derivative
-
A novel bicyclization reaction of two molecular allenyl ketones and isocyanides has been disclosed. This strategy allows for the construction of structurally complex spirocyclic lactam-lactone systems in an efficient manner. This protocol also demonstrate
- Yuan, Hongdong,Tang, Chongrong,Su, Shikuan,Cui, Lei,Jia, Xueshun,Li, Chunju,Li, Jian
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supporting information
p. 7231 - 7234
(2019/07/02)
-
- Cycloisomerization of Conjugated Allenones into Furans under Mild Conditions Catalyzed by Ligandless Au Nanoparticles
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Au nanoparticles supported on TiO2 (1 mol %) catalyze the quantitative cycloisomerization of conjugated allenones into furans under very mild conditions. The reaction rate is accelerated by adding acetic acid (1 equiv), but the acid does not participate in the protodeauration step as in the corresponding Au(III)-catalyzed transformation. The process is purely heterogeneous, allowing thus the recycling and reuse of the catalyst effectively in several runs.
- Zorba, Leandros,Kidonakis, Marios,Saridakis, Iakovos,Stratakis, Manolis
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supporting information
p. 5552 - 5555
(2019/08/01)
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- Fe-Catalyzed tandem cyclization for the synthesis of 3-nitrofurans from homopropargylic alcohols and Al(NO3)3·9H2O
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Al(NO3)3·9H2O as a nitro source for the synthesis of 3-nitrofurans from homopropargylic alcohols through Fe-catalyzed tandem cyclization is described. In this transformation, the substituted nitrofurans are obtained throug
- Wang, Ting,Jiang, Yong,Wang, Yanyan,Yan, Rulong
-
supporting information
p. 5232 - 5235
(2018/08/03)
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- Atom-Economical Palladium Carbon-Catalyzed de Novo Synthesis of Trisubstituted Nicotinonitriles
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A de novo palladium carbon-catalyzed synthesis of trisubstituted nicotinonitriles from easily synthesized homopropagylic or homoallylic aromatic alcohols in the presence of nitriles has been explored. The mechanism proceeds with an interesting generation
- Sarkar, Debayan,Rout, Nilendri,Ghosh, Manoj Kumar,Giri, Santanab,Neue, Kornelius,Reuter, Hans
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p. 9012 - 9022
(2017/09/11)
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- Electrophilic cyclization and intermolecular acetalation of 2-(4- hydroxybut-1-yn-1-yl)benzaldehydes: Synthesis of diiodinated diepoxydibenzo[c,k][1,9]dioxacyclohexadecines
-
An expedient strategy for the preparation of diiodinated diepoxydibenzo[c,k][1,9]dioxacyclohexadecines from readily available 2-(4-hydroxybut-1-yn-1-yl)- benzaldehydes through electrophile-triggered tandem cyclization/ intermolecular acetalation sequence
- Wang, Jia,Zhu, Hai-Tao,Chen, Si,Luan, Cheng,Xia, Yu,Shen, Yi,Li, Ying-Xiu,Hua, Yingxi,Liang, Yong-Min
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p. 10641 - 10649
(2018/05/31)
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- Regioselective propargylation of aldehydes using potassium allenyltrifluoroborate promoted by tonsil
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The propargylation of aldehydes using potassium allenyltrifluoroborate promoted by tonsil, an inexpensive and readily available clay, in a chemo- and regioselective way is described. The method is simple and avoids the use of air and moisture sensitive organometallics and products were obtained in good to moderate yields.
- Freitas, Jucleiton J.R.,Couto, Tulio R.,Cavalcanti, Italo H.,Freitas, Juliano C.R.,Barbosa, Queila P.S.,Oliveira, Roberta A.
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supporting information
p. 760 - 765
(2016/02/05)
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- Propargylation of aldehydes using potassium allenyltrifluoroborate
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The commercially available resin Amberlyst A-31 was efficiently used to promote the propargylation of aldehydes using potassium allenyltrifluoroborate. The method is simple and fast, and the products were obtained in short reaction times in high yields and purity at room temperature in a regio- and chemoselective manner.
- Couto, Tlio R.,Freitas, Jucleiton J. R.,Freitas, Juliano C. R.,Cavalcanti, Italo H.,Menezes, Paulo H.,Oliveira, Roberta A.
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- Diverging Pathways in the Activation of Allenes with Lewis Acids and Bases: Addition, 1,2-Carboboration, and Cyclization
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The reactions of allenes with frustrated (or cooperative) Lewis acid/base pairs result in the 1,4-addition of the base pair to the allene. The reactions of allenyl ketones and esters just in the presence of the strong Lewis acid B(C6F5/su
- Melen, Rebecca L.,Wilkins, Lewis C.,Kariuki, Benson M.,Wadepohl, Hubert,Gade, Lutz H.,Hashmi, A. Stephen K.,Stephan, Douglas W.,Hansmann, Max M.
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supporting information
p. 4127 - 4137
(2015/09/01)
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- Bu4N+ alkoxide-initiated/autocatalytic addition reactions with organotrimethylsilanes
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The use of Me3SiO-/Bu4N+ as a general activator of organotrimethylsilanes for addition reactions has been established. The broad scope of the method offers trimethylsilanes (including acetate, allyl, propargyl, benzyl, dithiane, heteroaryl, and aryl derivatives) as bench-stable organometallics that can be readily utilized as carbanion equivalents for synthesis. Reactions are achieved at rt without the requirement of specialized precautions that are commonplace for other organometallics.
- Das, Manas,O'Shea, Donal F.
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p. 5595 - 5607
(2014/07/08)
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- Silver-catalysed intramolecular hydroamination of alkynes with trichloroacetimidates
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Silver(i) complexes catalyse the intramolecular addition of trichloroacetimidates to alkynes. In the absence of a ligand, the selectivity of the reaction is dependent upon the nature of the counter-anion and solvent. The introduction of non-chelating nitrogeneous ligands suppresses competitive Bronsted acid catalysis, improving the yield and selectivity of the reaction.
- Wong, Valerie H. L.,Hor, T. S. Andy,Hii, King Kuok
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supporting information
p. 9272 - 9274
(2013/10/01)
-
- Efficient synthesis of γ-lactones via gold-catalyzed tandem cycloisomerization/oxidation
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A novel Au-catalyzed tandem cycloisomerization/oxidation of homopropargyl alcohols was developed. Various γ-lactones can be accessed readily by utilizing this strategy. Notably, the mechanism of this reaction is distinctively different from the related Ru-catalyzed reactions where the ruthenium vinylidene intermediate was proposed.
- Shu, Chao,Liu, Meng-Qi,Sun, Yu-Zhe,Ye, Long-Wu
-
supporting information
p. 4958 - 4961,4
(2012/12/12)
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- Efficient synthesis of γ-lactones via gold-catalyzed tandem cycloisomerization/oxidation
-
A novel Au-catalyzed tandem cycloisomerization/oxidation of homopropargyl alcohols was developed. Various γ-lactones can be accessed readily by utilizing this strategy. Notably, the mechanism of this reaction is distinctively different from the related Ru-catalyzed reactions where the ruthenium vinylidene intermediate was proposed.
- Shu, Chao,Liu, Meng-Qi,Sun, Yu-Zhe,Ye, Long-Wu
-
supporting information
p. 4958 - 4961
(2013/01/15)
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- Highly selective barbier-type propargylations and allenylations catalyzed by titanocene(III)
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The alkyne functional group is found in many bioactive natural products and is the key to many important chemical transformations developed over recent years. Moreover, allenes have recently gained relevance as versatile reagents in organic synthesis. Mild, catalytic methods to enable the selective introduction of either alkyne or allene motifs into organic molecules are very valuable but, as yet, quite scarce. We describe an extremely mild and selective method for either the propargylation or allenylation of carbonyl compounds catalyzed by the abundant, safe, and inexpensive metal titanium. These reactions can selectively provide homopropargylic alcohols from aldehydes and ketones or α-hydroxy-allenes from aldehydes. The mechanisms involved were also investigated. Copyright
- Munoz-Bascon, Juan,Sancho-Sanz, Iris,Alvarez-Manzaneda, Enrique,Rosales, Antonio,Oltra, J. Enrique
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supporting information
p. 14479 - 14486,8
(2020/08/24)
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- Gold-catalyzed oxidative rearrangement of homopropargylic ether via oxonium ylide
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Synthetically useful α,β-unsaturated carbonyl compounds were obtained from gold-catalyzed oxidative rearrangement of homopropargylic ether under mild reaction conditions. Gold carbenoid and oxonium ylide are proposed as key intermediates.
- Xu, Mei,Ren, Tian-Tian,Li, Chuan-Ying
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supporting information
p. 4902 - 4905,4
(2020/09/16)
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- InI3- or ZnI2-catalyzed reaction of hydroxylated 1,5-allenynes with thiols: A new access to 3,5-disubstituted toluene derivatives
-
Transition-metal-activated alkynes or allenes can accept nucleophilic attack and undergo direct addition of the nucleophiles to the unsaturated bonds or trigger subsequent rearrangement reactions. This chemistry has witnessed increasing development in recent years. In this report, we have focused on the metal-catalyzed reactions of a variety of substituted propargyl allenic alcohols and thiophenols using indiumACHTUNGTRENUNG(III) and zinc(II) catalysts, which can activate both the alcohol and alkyne. In this reaction, thio groups play the role of a nucleophile and trigger subsequent rearrangements to give benzene derivatives. The products can be further transformed into various 1,3,5-trisubstituted aromatic compounds by nickel-catalyzed coupling reactions through the cleavage of the C-S bonds.
- Ma, Jie,Peng, Lingling,Zhang, Xiu,Zhang, Zhe,Campbell, Melody,Wang, Jianbo
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experimental part
p. 2214 - 2220
(2011/06/19)
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- One-pot, solvent-free regioselective addition reactions of propargyl bromide to carbonyl compounds mediated by Zn-Cu couple
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A Barbier-type propargylation of carbonyl compounds with propargyl bromide has been achieved with reactive zinc-copper couple under solvent-free conditions. The reaction of aldehydes with propargyl bromide produced the unique homopropargyl alcohols in excellent yields at room temperature without the formation of homoallenyl alcohols. The ketones reacted with propargyl bromide to give the corresponding homopropargyl alcohols in good to excellent yields at -14 to -16 °C. The advantages of this method are excellent yields, short reaction time, high regioselectivity, and avoidance of the use of organic solvents.
- Ma, Xiaofang,Wang, Jin-Xian,Li, Shunxi,Wang, Ke-Hu,Huang, Danfeng
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experimental part
p. 8683 - 8689
(2009/12/24)
-
- Efficient synthesis of 3-chloromethyl-2(5H)-furanones and 3-chloromethyl- 5,6-dihydropyran-2-ones via the PdCl2-catalyzed chlorocyclocarbonylation of 2,3- or 3,4-allenols
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(Chemical Equation Presented) A mild and efficient methodology involving PdCl2-catalyzed chlorocyclocarbonylation of 2,3- or 3,4-allenols with CuCl2 for the synthesis of 3-chloromethyl-2(5H)-furanones and 3-chloromethyl-5,6-dihydropyran-2-ones was developed. This reaction proceeded in a highly regioselective manner, i.e., the chlorine atom was introduced to the terminal position of the allene moiety while the lactone linkage was formed between the center carbon atom of the allene moiety and the hydroxyl oxygen, which was established by the X-ray single crystal diffraction study of γ-lactone 3p. The highly optically active 3-chloromethyl-2(5H)-furanones could be easily prepared from the readily available optically active 2,3-allenols. A mechanism for this reaction was proposed.
- Cheng, Xin,Jiang, Xuefeng,Yu, Yihua,Ma, Shengming
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scheme or table
p. 8960 - 8965
(2009/04/11)
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- A simple approach to separate a mixture of homopropargylic and allenic alcohols
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(Chemical Equation Presented) A simple and practical approach to separate homopropargylic alcohol from allenic alcohol has been developed. It involves the formation of an insoluble silver acetylide species between silver nitrate and homopropargylic alcohol in aqueous acetone which can be separated from the allenic alcohol through a simple filtration. The homopropargylic alcohol can subsequently be recovered by hydrolysis with 1 N HCl. This protocol has been applied to the separation of a mixture of chiral homopropargylic and allenic alcohols in excellent yields with retention of absolute stereochemistry.
- Fu, Fan,Hoang, Kim Le Mai,Loh, Teck-Peng
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supporting information; experimental part
p. 3437 - 3439
(2009/05/07)
-
- Carbonyl propargylation and allenylation with 2-propynyl mesylates, tin(IV) iodide, and tetrabutylammonium iodide controlled by either a steric effect or coordination effect
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A combination of tin(IV) iodide and tetrabutylammonium iodide can be used for propargylation or allenylation of aldehydes with 2-propynyl mesylates in dichloromethane. 1-Methyl-2-propynyl mesylate or 2-butynyl mesylate results in propargylation or allenyl
- Masuyama, Yoshiro,Yamazuki, Ryouichi,Ohtsuka, Masaru,Kurusu, Yasuhiko
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p. 1750 - 1752
(2008/02/03)
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- Rapid and solvent-free synthesis of homoallyl or homopropargyl alcohols mediated by zinc powder
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A rapid and efficient procedure for the solvent-free synthesis of homoallylic and homopropargyl alcohols has been achieved by zinc-mediated Barbier-type reaction of carbonyl compounds at room temperature. Georg Thieme Verlag Stuttgart.
- Wang, Jin-Xian,Jia, Xuefeng,Meng, Tuanjie,Xin, Li
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p. 2838 - 2844
(2007/10/03)
-
- Experimental and theoretical studies of the propargyl-allenylindium system
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The transient organoindium intermediates formed in the reaction of propargyl bromide with indium in aqueous media and tetrahydrofuran were investigated by NMR spectroscopy and found to be allenylindium(I) and allenylindium(III) dibromide. The influence of
- Miao, Weishi,Chung, Lung Wa,Wu, Yun-Dong,Chan, Tak Hang
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p. 13326 - 13334
(2007/10/03)
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- Carbonyl allenylations and propargylations by 3-chloro-1-propyne or 2-propynyl mesylates with tin(IV) chloride and tetrabutylammonium iodide
-
By the use of tin(IV) chloride and tetrabutylammonium iodide in dichloromethane, 3-chloro-1-propyne or 2-propynyl mesylate can be applied to allenylation and propargylation of aldehydes (carbonyl allenylation and propargylation) to produce a mixture of 1-
- Masuyama, Yoshiro,Watabe, Akiko,Kurusu, Yasuhiko
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p. 1713 - 1715
(2007/10/03)
-
- Palladium(0) catalyzed regioselective carbonyl propargylation across tetragonal tin(II) oxide via redox transmetallation
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Facile homopropargylation of aldehydes by propargyl bromides over tetragonal tin(II)oxide and catalytic palladium(0) occurs which is proposed to involve the prior formation of dinuclear allenylpalladium followed by redox transmetallation to β-SnO.
- Banerjee, Moloy,Roy, Sujit
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p. 534 - 535
(2007/10/03)
-
- The high stereoselective synthesis of β-alkynyl-enol phosphates
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A high stereoselective synthesis for β-alkynyl-enol phosphates from β-alkynyl ketone and dialkyl phosphite, via Atherton-Todd reaction, was reported. NaH as base gave a nearly pure Z-isomer.
- Ding,Huang
-
p. 449 - 454
(2007/10/03)
-
- Carbon-carbon bond formation reaction promoted by cadmium in aqueous media
-
Promoted by metallic cadmium allylilic and propargyl bromides react smoothly with aldehydes in aqueous DMF to give homoallylic and homopropargyl alcohols in moderate to good yields. It can also promote pinacol coupling of aromatic aldehydes. The metallic cadmium is produced in situ by the reduction of CdCl2 · H2O with samarium metal.
- Zheng,Bao,Zhang
-
p. 3517 - 3521
(2007/10/03)
-
- Highly selective synthesis of acetylenic alcohols promoted by metallic dysprosium in the presence of mercuric chloride
-
Promoted by metallic dysprosium, carbonyl compounds react smoothly with propargyl bromide to afford the corresponding homopropargylic alcohols in good to excellent yields without observation of allenic alcohols. In addition, this reaction is regioselective and chemoselective.
- Li, Zhiming,Jia, Yu,Zhou, Jingyao
-
p. 2515 - 2524
(2007/10/03)
-
- Gallium-mediated highly regioselective reaction of allyl-type bromide and propargyl-type bromide with aldehyde
-
In the presence of potassium iodide and lithium chloride, the one-pot reaction of gallium powder, allyl-type bromide and aldehyde shows very high selectivity favoring α-adducts. Under the same condition, the reaction of propargylic bromide with aldehyde e
- Han, Ying,Chi, Zhengfa,Huang, Yao-Zeng
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p. 1287 - 1296
(2007/10/03)
-
- Zinc Barbier reaction of propargyl halides in water
-
The reaction of propargyl halides and carbonyl compounds with zinc powder proceeds in concentrated aqueous salt solutions affording with high selectivity homopropargylic alcohols preparatively useful yields are obtained with aromatic and aliphatic aldehydes. Ketones and 2-hydroxybenzaldehydes react partially. A surface process of two SET is discussed.
- Bieber, Lothar W.,Da Silva, Margarete F.,Da Costa, Rosenildo C.,Silva, Lilia O.S.
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p. 3655 - 3658
(2007/10/03)
-
- Zinc-promoted Barbier-type reaction of propargyl bromide with aldehydes in aqueous media
-
In the presence of metallic zinc, propargyl bromide is found to react with aldehydes at room temperature in tetrahydrofurane-saturated aqueous ammonium chloride (5:2) to afford the corresponding homopropargylic alcohols in moderate to high yields together
- Yavari,Riazi-Kermani
-
p. 2923 - 2928
(2007/10/03)
-
- On pentaorganylstiborane. III. Regio- and diastereoselective additions of acetylenic and allenic organoantimony compounds to aldehydes
-
The reaction of propargyl bromide (4a) with tributylstibine gave allenyltributylstibonium bromide (5), and its corresponding pentaorganylstiborane reacted with aldehyde to give homopropargylic alcohol (10a) exclusively in good yield.However, the reaction
- Zhang, Li-Jun,Mo, Xue-Sheng,Huang, Yao-Zeng
-
-
- Selective Synthesis of Allenic and Acetylenic Derivatives via Pentaorganylstiboranes
-
Allenyltetrabutylstiborane (3), formed from allenyltributylstibonium bromide (2) and butylmagnesium bromide, reacted with aldehydes to give homopropargylic alcohols (4) exclusively in excellent yields, while 2-butynyltetrabutylstiborane (6), formed from 2
- Zhang, Li-Jun,Huang, Yao-Zeng,Huang, Zhe-Hui
-
p. 6579 - 6582
(2007/10/02)
-
- Reaction of Propargyl Bromide with Aldehydes in the Presence of Metallic Tin. Synthesis of Homopropargylalcohols and Homoallenylalcohols
-
In the presence of water, metallic tin and propargyl bromide reacted smoothly with aldehydes to give the corresponding homopropargyl alcohols (a) and homoallenyl alcohols (b).High chemospecifity to bifunctional carbonyl compounds containing -OH, -X and -NO2 etc. was obtained.
- Wu, Shihui,Huang, Bangzhou,Gao, Xiang
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p. 1279 - 1286
(2007/10/02)
-
- Lead Promoted Barbier-Type Reaction of Propargyl Bromide with Aldehydes
-
The first example of lead promoted "Barbier-type" (in situ Grignard) reaction has been demonstrated by the reaction of propargyl bromide with aldehydes in a Pb/Bu4NBr/Me3SiCl/DMF system.
- Tanaka, Hideo,Hamatani, Takeshi,Yamashita, Shiro,Torii, Sigeru
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p. 1461 - 1462
(2007/10/02)
-
- Carbon-Carbon Bond-Forming Reactions Using Cerium Metal or Organocerium(III) Reagents
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Carbon-carbon bond-forming reactions using cerium metal or organocerium(III) reagents have been investigated.Cerium amalgam is an effective reagent for the chemoselective preparation of homoallylic alcohols from allyl halides and carbonyl compounds.These same reagent can also be satisfactorily employed for the Reformatsky-type reaction of α-halo esters with carbonyl compounds.It has been shown that organocerium(III) reagents are conveniently generated by the reaction of organolithiums with cerium(III)iodide or cerium(III)chloride.The reagents are less basic thanorganolithiums or Grignard reagents, and they react cleanly at -78 to -65 deg C with various carbonyl compounds to afford the addition products in high yields, even though the substrates are susceptible to enolization or metal-halogen exchange with simple organolithiums.The same reagents react also with α,β-unsaturated compounds to yield 1,2-addition products in high selectivity.
- Imamoto, Tsuneo,Kusumoto, Tetsuo,Tawarayama, Yoshinori,Sugiura, Yasushi,Mita, Takeshi,et al.
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p. 3904 - 3912
(2007/10/02)
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