- A new coupling reaction of propargyl carbonates mediated by Ti(OiPr)2Cl2/Mg
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A new homocoupling reaction of 1,1-disubstituted propargyl carbonates or 1-monosubstituted propargyl carbonates, mediated by Ti(OiPr)2Cl2/Mg in ether at 0°C, was found to form symmetric 1,5-hexadiynes and 1-allenyl-5-ynes in moderate
- Yang, Fanglong,Zhao, Gang,Ding, Yu,Zhao, Zongbao,Zheng, Yueqing
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Read Online
- The Rupe rearrangement: A new efficient method for large-scale synthesis of unsaturated ketones in the pilot plant
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During scale-up studies of a new steroidal drug, the Rupe rearrangement of an intermediate was investigated in detail. As the traditional method for this reaction was not adaptable safely to conditions for the pilot plant, a new procedure had to be develo
- Weinmann, Hilmar,Harre, Michael,Neh, Harribert,Nickisch, Klaus,Skoetsch, Carlo,Tilstam, Ulf
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Read Online
- A highly efficient, practical, and general route for the synthesis of (R3P)2Pd(0): Structural evidence on the reduction mechanism of Pd(II) to Pd(0)
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(Equation Presented). A highly efficient, practical, and general method was developed to synthesize a family of (R3P)2Pd(0) complexes, using a stoichiometric amount of phosphine ligands and readily available Pd(II) precursors. The st
- Li, Hongbo,Grasa, Gabriela A.,Colacot, Thomas J.
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Read Online
- Development of an aquacatalytic system based on the formation of vesicles of an amphiphilic palladium NNC-pincer complex
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Two amphiphilic palladium NNC-pincer complexes bearing hydrophilic tri(ethylene glycol) chains and hydrophobic dodecyl chains were designed and prepared for the development of a new aquacatalytic system. In water, these amphiphilic complexes self-assembled to form vesicles, the structures which were established by means of a range of physical techniques. When the catalytic activities of the vesicles were investigated in the arylation of terminal alkynes in water, they were found to catalyze the reaction of aryl iodides with terminal alkynes to give good yields of the corresponding internal alkynes. The formation of a vesicular structure was shown to be essential for efficient promotion of this reaction in water.
- Sakurai, Fumie,Hamasaka, Go,Uozumi, Yasuhiro
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Read Online
- A novel synthesis of (Z)-enynes and (Z)-enediynes from prop-2-ynyl alcohols
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The conjugated (Z)-enynes and (Z)-enediynes were synthesized by dehydration of prop-2-ynyl alcohols with polyphosphoric acid trimethysilyl ester.
- Yoshimatsu,Yamada,Shimizu,Kataoka
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Read Online
- One-pot Sonogashira–Hydroarylation reaction catalyzed by anionic palladium complexes in an aqueous medium
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It was found that anionic Pd(II) complexes of type [CA]2[PdCl4] and [CA]2[Pd2Cl6] (CA = imidazolium or pyridinium cation) are effective catalysts for copper-free Sonogashira coupling in an aqueous med
- Dziadas, M.,Trzeciak, A. M.,Wójcik, E.
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supporting information
(2022/01/26)
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- Sodium-metal-promoted reductive 1,2-syn-diboration of alkynes with reduction-resistant trimethoxyborane
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Reductive 1,2-diboration of alkynes has been accomplished by means of sodium dispersion in the presence of trimethoxyborane as a reduction-resistant boron electrophile. Two boron moieties can be introduced onto alkynes with excellent syn selectivity to afford the corresponding (Z)-1,2-diborylalkenes. Bis(borate) species generated in situ can be involved in one-pot Suzuki-Miyaura arylation, formal arylboration of alkynes thus being executed.
- Fukazawa, Mizuki,Ito, Shiori,Nogi, Keisuke,Takahashi, Fumiya,Yorimitsu, Hideki
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p. 1171 - 1179
(2020/10/18)
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- Copper-Catalyzed Radical 1,4-Difunctionalization of 1,3-Enynes with Alkyl Diacyl Peroxides and N-Fluorobenzenesulfonimide
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Many reactions involving allenyl ion species have been studied, but reactions involving allenyl radicals are less well understood, perhaps because of the inconvenience associated with the generation of short-lived allenyl radicals. We describe here a versatile method for the generation of allenyl radicals and their previously unreported applications in the intermolecular 1,4-carbocyanation and 1,4-sulfimidocyanation of 1,3-enynes. With the assistance of the trifunctional reagents, alkyl diacyl peroxides or N-fluorobenzenesulfonimide, a range of synthetically challenging multisubstituted allenes can be prepared with high regioselectivity. These multisubstituted allenes can be easily transformed into synthetically useful structures such as fluorinated vinyl cyanides, lactones, functionalized allenyl amides, 1-aminonaphthalenes, and pyridin-2(1H)-ones, and several novel transformations are reported. The results of radical scavenger and radical clock experiments are consistent with the proposed allenyl radical pathway. Density functional theory (DFT) and IR spectroscopy studies suggest the formation of an isocyanocopper(II) species in the ligand exchange step. On the basis of the results of IR, DFT, and diastereoselectivity studies, an isocyanocopper(II)/copper(I) catalytic cycle is proposed, which differs from the previously considered Cu(III) mechanism in cyanation reactions.
- Zhu, Xiaotao,Deng, Weili,Chiou, Mong-Feng,Ye, Changqing,Jian, Wujun,Zeng, Yuehua,Jiao, Yihang,Ge, Liang,Li, Yajun,Zhang, Xinhao,Bao, Hongli
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p. 548 - 559
(2019/01/04)
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- Cyclic eneyne compound and synthesis method thereof
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The invention relates to a cyclic eneyne compound and a preparation method thereof. The chemical formula is described in the description, wherein substituent R is any one of phenyl or p-methylphenyl or isohexyl or n-heptyl, ring is a five-membered ring or
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Paragraph 0031-0034
(2017/10/05)
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- Copper-catalyzed silylation reactions of propargyl epoxides: Easy access to 2,3-allenols and stereodefined alkenes
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Efficient silylation reactions of propargyl epoxides catalyzed by copper catalysts have been developed. Under mild reaction conditions, tri- and tetra-substituted functionalized allenols and alkenes could be selectively obtained in moderate to high yields
- Chang, Xi-Hao,Liu, Zheng-Li,Luo, Yun-Cheng,Yang, Chao,Liu, Xiao-Wei,Da, Bing-Chao,Li, Jie-Jun,Ahmad, Tanveer,Loh, Teck-Peng,Xu, Yun-He
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supporting information
p. 9344 - 9347
(2017/08/23)
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- Scope and limitations of a DMF bio-alternative within Sonogashira cross-coupling and Cacchi-type annulation
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Pd-catalysed C-C bond formation is an essential tool within the pharmaceutical and agrochemical industries. Many of these reactions rely heavily on polar aprotic solvents; however, despite their utility, these solvents are incompatible with the drive towards more sustainable chemical synthesis. Herein, we describe the scope and limitations of an alternative to DMF derived from renewable sources (Cyrene) in Sonogashira cross-coupling and Cacchi-type annulations.
- Wilson, Kirsty L.,Kennedy, Alan R.,Murray, Jane,Greatrex, Ben,Jamieson, Craig,Watson, Allan J. B.
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supporting information
p. 2005 - 2011
(2016/10/05)
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- Titanium-Promoted Cross-Coupling for the Selective Synthesis of Polysubstituted, Conjugated Amides
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α,β-Unsaturated amides are important building blocks and are key structural elements in a number of biologically active natural products. Despite their importance and prevalence, few methods exist to prepare conjugated amides directly and modularly. To address this gap, a titanium-promoted coupling of alkynes and isocyanates has been developed. The method is highly stereoselective, producing only the E isomer with good chemoselectivity and regioselectivity (>95/5), for unsymmetrical internal alkynes that contain a steric bias. The reactive titanacyclopentene intermediate formed from the coupling of the alkyne and isocyanate was additionally reacted with various electrophiles to access tetrasubstituted enamides.
- Chenniappan, Vinoth Kumar,Rahaim, Ronald J.
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supporting information
p. 5090 - 5093
(2016/10/14)
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- Manganese-catalyzed Sonogashira coupling of aryl iodides
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An interesting manganese-catalyzed Sonogashira coupling reaction of aryl iodides has been developed. With PEG-400 as the green solvent and under mild reaction conditions, a variety of diarylacetylenes were obtained in moderate to good yields.
- Qi, Xinxin,Jiang, Li-Bing,Wu, Xiao-Feng
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supporting information
p. 1706 - 1710
(2016/04/04)
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- Ligand-Assisted Gold-Catalyzed Cross-Coupling with Aryldiazonium Salts: Redox Gold Catalysis without an External Oxidant
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Gold-catalyzed C(sp)-C(sp2) and C(sp2)-C(sp2) cross-coupling reactions are accomplished with aryldiazonium salts as the coupling partner. With the assistance of bpy ligand, gold(I) species were oxidized to gold(III) by diazonium without any external oxidants. Monitoring the reaction with NMR and ESI-MS provided strong evidence for the nitrogen extrusion followed by AuIII reductive elimination as the key step.
- Cai, Rong,Lu, Mei,Aguilera, Ellen Y.,Xi, Yumeng,Akhmedov, Novruz G.,Petersen, Jeffrey L.,Chen, Hao,Shi, Xiaodong
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p. 8772 - 8776
(2015/11/27)
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- Palladium-catalyzed cross-coupling reactions of triarylbismuthanes with terminal alkynes under aerobic conditions
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Abstract A simple Pd-catalyzed Sonogashira-type cross-coupling reaction using of triarylbismuthanes is described. The reaction of triarylbismuthanes with terminal alkynes in the presence of 5 mol% of Pd(OAc)2, 6 equiv. AgF and 6 equiv. K3PO4 at room temperature afforded the coupling products in good to excellent yield. The reaction proceeded effectively under aerobic conditions, and all three aryl groups on bismuth could be transferred to the coupling products. The reaction was sensitive to the electronic nature of the triarylbismuthanes: substrates bearing an electron-withdrawing group on the aromatic ring showed higher reactivity than those having an electron-donating group.
- Matsumura, Mio,Yamada, Mizuki,Tsuji, Toshiyuki,Murata, Yuki,Kakusawa, Naoki,Yasuike, Shuji
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- Cyclization of Diaryl(hetaryl)alkynes under Selenobromination Conditions: Regioselectivity and Mechanistic Studies
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The cyclization of substituted diaryl(hetaryl)alkynes with in-situ-prepared SeBr4 has been achieved. The use of an alkene additive as a bromine scavenger gives simple access to functionalized benzo[b]selenophene and selenophenothiophene derivatives from commercially available or easily accessible starting materials. The reactions can be performed in air without the use of moisture-sensitive reagents, dry solvents, or an inert atmosphere. Mechanistic studies confirmed a regioselective anti 1,2-addition in the selenobromination step, and a subsequent electrophilic substitution in the aromatic ring to complete the cyclization. The cyclization of substituted diaryl(hetaryl)alkynes with in-situ-prepared SeBr4 has been achieved. The use of an alkene additive as a bromine scavenger gives simple access to functionalized benzo[b]selenophene and selenophenothiophene derivatives from commercially available or easily accessible starting materials.
- Paegle, Edgars,Belyakov, Sergey,Petrova, Marina,Liepinsh, Edvards,Arsenyan, Pavel
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supporting information
p. 4389 - 4399
(2015/07/27)
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- Rh-catalyzed decarbonylation of conjugated ynones via carbon-alkyne bond activation: Reaction scope and mechanistic exploration via DFT calculations
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In this full article, detailed development of a catalytic decarbonylation of conjugated monoynones to synthesize disubstituted alkynes is described. The reaction scope and limitation has been thoroughly investigated, and a broad range of functional groups
- Dermenci, Alpay,Whittaker, Rachel E.,Gao, Yang,Cruz, Faben A.,Yu, Zhi-Xiang,Dong, Guangbin
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p. 3201 - 3210
(2015/06/17)
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- Copper-catalyzed regioselective reaction of internal alkynes and diaryliodonium salts
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The copper-catalyzed highly regioselective reaction of internal alkynes with diaryliodonium salts was achieved for the first time. α-Arylketones were obtained in moderate to good yields from arylpropargylic alcohols or aryl alkyl alkynes under mild condit
- Xu, Ze-Feng,Cai, Chen-Xin,Liu, Jin-Tao
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supporting information
p. 2096 - 2099
(2013/06/05)
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- Heck alkynylation (copper-free sonogashira coupling) of aryl and heteroaryl chlorides, using Pd complexes of t -Bu2(p -NMe2C 6H4)P: Understanding the structure-activity relationships and copper effects
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L2Pd(0) and L2Pd(II) complexes, where L= t-Bu 2(p-NMe2C6H4)P, have been identified as efficient catalyst systems for the Heck alkynylation of a variety of aryl bromides (17 examples) and aryl/heteroaryl chlorides (31 examples) with a range of aryl- and alkyl-acetylenes in excellent yields, under relatively low Pd loadings. The single-crystal X-ray structure determination of the presumably active catalytic species, L2Pd(0), was carried out in this study to better understand the superior activity of the current catalyst system from a structure-activity relationship point of view. The P-Pd-P bond angle indicates that the complex is bent (174.7) in comparison to the perfectly linear (180.0) structure of the analogous Pd(t-Bu3P)2. Preliminary mechanistic studies on the negative copper effect and substrate effect of aryl acetylenes were conducted to better understand the cross-coupling pathway of Heck alkynylation.
- Pu, Xiaotao,Li, Hongbo,Colacot, Thomas J.
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p. 568 - 581
(2013/03/13)
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- Highly stereoselective and scalable synthesis of trans -fused octahydrocyclohepta[ b ]pyrrol-4(1 H)-ones via the aza-Cope-Mannich rearrangement in racemic and enantiopure forms
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We have developed an efficient and stereoselective route to trans-fused octahydrocyclohepta[b]pyrrol-4(1H)-ones. The key features of our synthesis include the regioselective epoxide ring-opening of alkynyl oxiranes and a stereoselective aza-Cope-Mannich r
- Belov, Dmitry S.,Lukyanenko, Evgeny R.,Kurkin, Alexander V.,Yurovskaya, Marina A.
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p. 10125 - 10134
(2013/01/15)
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- Synthesis of 2-phenyl-4,5,6,7-tetrahydro-1H-indoles with a chiral substituent at the nitrogen atom
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An efficient method has been developed for the enantioselective synthesis of 2-phenyl-4,5,6,7-tetra-hydro-1H-indoles containing chiral substituents at the nitrogen atom. It is based on opening of the epoxide fragment of 1-phenylethynyl-7-oxabicyclo[4.1.0]
- Andreev, I. A.,Ryzhkov, I. O.,Kurkin, A. V.,Yurovskaya, M. A.
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p. 715 - 719,5
(2020/09/09)
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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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p. 7092 - 7097
(2012/10/07)
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- Copper-catalyzed highly selective semihydrogenation of non-polar carbon-carbon multiple bonds using a silane and an alcohol
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A copper catalyst bearing a suitable Xantphos derivative or NHC ligand was found to be highly efficient for the selective semihydrogenation of non-polar unsaturated compounds using a mixture of a silane and an alcohol as reducing agent. The catalytic system was useful for the selective semihydrogenation of internal alkynes to (Z)-alkenes with suppression of overreduction to the corresponding alkanes. Furthermore, semihydrogenations of terminal alkyne, 1,2-diene, 1,3-diene, 1,3-enyne and 1,3-diyne systems were also achieved selectively. Copyright
- Semba, Kazuhiko,Fujihara, Tetsuaki,Xu, Tinghua,Terao, Jun,Tsuji, Yasushi
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supporting information; experimental part
p. 1542 - 1550
(2012/08/08)
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- Waste-free catalytic propargylation/allenylation of aryl and heteroaryl nucleophiles and synthesis of naphthopyrans
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A general method for the substitution of propargylic alcohols with electron-rich aromatic carbocycles and heterocycles has been developed. The reaction occurs under simple, mild conditions, and employs an inexpensive environmentally benign and recoverable
- McCubbin, J. Adam,Nassar, Costa,Krokhin, Oleg V.
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experimental part
p. 3152 - 3160
(2011/10/30)
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- Copper-free sonogashira coupling reaction using a trans-spanning 1,2-Bis(2-thienylethynyl)benzene Ligand
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Novel copper-free Sonogashira coupling reaction of aryl halides with terminal acetylenes proceeded in the presence of 1,2-bis(2-thienylethynyl) benzene (1) as a trans-bidentatable ligand.
- Atobe, Shingo,Sonoda, Motohiro,Suzuki, Yuki,Shinohara, Hiroyuki,Yamamoto, Takuya,Ogawa, Akiya
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supporting information; experimental part
p. 925 - 927
(2011/12/05)
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- Double dehydro-diels-alder reactions of 1,5-dien-3-ynes
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A study was conducted to demonstrate double dehydro-diels-alder reactions of 1,5-dien-3-ynes. It was demonstrated that the reaction proceeded through two concerted cycloadditions, the first of which was proposed to be reversible. Detailed analysis reveale
- Fallon, Thomas,Robinson, Diane E.J.E.,Willis, Anthony C.,Paddon-Row, Michael N.,Sherburn, Michael S.
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supporting information; experimental part
p. 760 - 765
(2010/05/18)
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- Copper- and base-free Sonogashira-type cross-coupling reaction of triarylantimony dicarboxylates with terminal alkynes under an aerobic condition
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A simple copper- and base-free palladium-catalyzed Sonogashira-type cross-coupling by the use of triarylantimony dicarboxylates is described. Reaction of triarylantimony diacetates with terminal alkynes in the presence of 1 mol % of PdCl2(PPhs
- Wang, Xuan,Qin, Weiwei,Kakusawa, Naoki,Yasuike, Shuji,Kurita, Jyoji
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experimental part
p. 6293 - 6297
(2010/01/18)
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- Copper-catalyzed 2:1 Coupling reaction of arynes with alkynes
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(Chemical Equation Presented) A formal insertion reaction of two molar amounts of arynes into a C-H bond of terminal alkynes is efficaciously catalyzed by copper(1) chloride, giving 2-alkynylbiaryls in one step.
- Yoshida, Hiroto,Morishita, Takami,Nakata, Hiromi,Ohshita, Joji
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supporting information; experimental part
p. 373 - 376
(2009/08/08)
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- Silver(I)-catalyzed cascade: Direct access to furans from alkynyloxiranes
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(Chemical Equation Presented) Functionalized furans are conveniently formed by a new silver(I)-catalyzed reaction of alk-1-ynyl oxiranes in the presence of p-toluenesulfonic acid and methanol. Evidence supported a cascade mechanism.
- Blanc, Aurelien,Tenbrink, Katharina,Weibel, Jean-Marc,Pale, Patrick
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supporting information; experimental part
p. 4360 - 4363
(2009/09/06)
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- Mechanistic studies and improvement of coinage metal-catalyzed transformation of alkynyloxiranes to furans: An alcohol addition-cyclization- elimination cascade
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(Chemical Equation Presented) In the presence of alcohol Ag or Au salts or complexes catalyze the conversion of alkynyloxiranes to substituted furans. Both catalysts are effective, and a large furan diversity can be obtained in high yield with one or the
- Blanc, Aurelien,Tenbrink, Katharina,Weibel, Jean-Marc,Pale, Patrick
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supporting information; experimental part
p. 5342 - 5348
(2009/12/03)
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- Copper-catalyzed alkyne-aryne coupling reaction under microwave conditions: preparation of unsymmetric and symmetric di-substituted alkynes
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Several unsymmetric and symmetric alkynes were prepared excellent to modest yields by generating benzyne from the reaction of 2-(trimethylsilyl)phenyl triflate with CsF in the presence of CuI and terminal alkyne under microwave heating for 30 min at 150 °
- Akubathini, Shashidhar Kumar,Biehl, Ed
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scheme or table
p. 1809 - 1811
(2009/07/05)
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- Efficient synthesis of substituted 3-iodofurans by electrophilic cyclization of propargylic oxirane derivatives
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The electrophilic cyclization of various propargylic oxirane compounds and I2 offers an efficient and straightforward route to highly substituted iodofurans under mild reaction conditions. Further functionalization has demonstrated that the iod
- Xie, Yong-Xin,Liu, Xue-Yuan,Wu, Lu-Yong,Han, Yao,Zhao, Lian-Biao,Fan, Ming-Jin,Liang, Yong-Min
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supporting information; experimental part
p. 1013 - 1018
(2009/04/11)
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- Copper-catalyzed alkyne-aryne and alkyne-alkene-aryne coupling reactions
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(Chemical Equation Presented) The efficient copper-catalyzed two-component coupling reaction of alkynes with arynes and the three-component coupling reaction of alkynes with allylic chlorides and arynes have been developed. Copper acetylide was postulated as a transient intermediate for the initiation of the coupling reactions.
- Xie, Chunsong,Liu, Leifang,Zhang, Yuhong,Xu, Peixin
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supporting information; experimental part
p. 2393 - 2396
(2009/05/11)
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- Cp*Li as a base: application to palladium-catalyzed cross-coupling reaction of aryl-X or alkenyl-X (X=I, Br, OTf, ONf) with terminal acetylenes
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The reaction of aryl-X or alkenyl-X (X=I, Br, OTf, ONf) with terminal acetylenes in the presence of a catalytic amount of Pd(OAc)2 provided the alkynylated products in good yields by using Cp*Li (Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) as a base.
- Uemura, Minoru,Yorimitsu, Hideki,Oshima, Koichiro
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p. 1829 - 1833
(2008/09/18)
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- Palladium-catalyzed diastereoselective coupling of propargylic oxiranes with terminal alkynes
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A diastereoselective coupling of propargylic oxiranes with terminal alkynes has been developed with use of a palladium catalyst. The stereochemistries of the resulting 4-alkynyl-substituted 2,3-allenols have been altered depending on the palladium catalyst. An optically active antf-substituted aliene was synthesized from the reaction of an enantiomerically enriched propargylic oxirane without loss of chirality.
- Yoshida, Masahiro,Hayashi, Maiko,Shishido, Kozo
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p. 1643 - 1646
(2008/02/02)
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- High throughput evaluation of the production of substituted acetylenes by the Sonogashira reaction followed by the Mizoroki-Heck reaction in ionic liquids, in situ, using a novel array reactor
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The parallel Sonogashira coupling reaction was carried out under copper-free condition by integrating the advantages of ionic liquids as the reaction media followed by the simultaneous-multiple Mizoroki-Heck reaction in situ by the use of a novel array re
- Rahman, Md. Taifur,Fukuyama, Takahide,Ryu, Ilhyong,Suzuki, Kanae,Yonemura, Koichi,Hughes, Philip F.,Nokihara, Kiyoshi
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p. 2703 - 2706
(2007/10/03)
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- Palladium-catalyzed cross-coupling reaction of ethynylstibanes with organic halides
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The reaction of ethynylstibanes (1a-g) with vinyl halides or triflate in the presence of a palladium catalyst led to the formation of cross-coupling products (5a-g, 10-12) in good to moderate yield, along with homo-coupling products (6a-g). A similar reaction of ethynyldiphenylstibane (1a) with aryl iodides (13a-i) also gave cross-coupling products (14a-i), although the yields were relatively low. The yields of the cross-coupling products were highly dependent on the nature of the solvent employed, and good results were obtained when the reaction was carried out in HMPA or amines such as diethylamine and morpholine. The results imply that HMPA and amine used as solvents facilitate transmetallation of the ethynyl group on 1 to the palladium by intermolecular coordination between antimony and oxygen (for HMPA) or nitrogen (for amine).
- Kakusawa, Naoki,Yamaguchi, Kouichiro,Kurita, Jyoji
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p. 2956 - 2966
(2007/10/03)
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- Tetraarylphosphonium halides as arylating reagents in Pd-catalyzed heck and cross-coupling reactions
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(Chemical Equation Presented) Highly efficient: Tetraarylphosphonium halides, Ar4P+X-, as arylating reagents efficiently deliver an aryl group in Pd-catalyzed reactions with olefins, organoboron compounds, and terminal alkynes (see scheme).
- Hwang, Lee Kyoung,Na, Youngim,Lee, Junseong,Do, Youngkyu,Chang, Sukbok
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p. 6166 - 6169
(2007/10/03)
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- Pt(0)-catalyzed alkynylation of aryl iodides with lithium alkynyltriisopropoxy borates
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An efficient cross coupling reaction of various lithium alkynyltriiospropoxyborates with a wide array of aryl iodides was catalyzed by Pt(PPh3)4-CuI in DMF as a solvent. These cross coupling reactions are general and permit the new sp-sp2 carbon-carbon bond formation.
- Oh, Chang Ho,Reddy, V. Raghava
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p. 2091 - 2094
(2007/10/03)
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- A copper- and amine-free Sonogashira reaction employing aminophosphines as ligands
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An efficient Pd-catalyzed Sonogashira coupling reaction was achieved in the absence of a copper salt or amine with an inorganic base and easily prepared, air-stable aminophosphine ligands in commonly used organic solvents; good to excellent yields were ob
- Cheng, Jiang,Sun, Yanhui,Wang, Feng,Guo, Minjie,Xu, Jian-Hua,Pan, Yi,Zhang, Zhaoguo
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p. 5428 - 5432
(2007/10/03)
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- Sonogashira coupling using bulky palladium-phenanthryl imidazolium carbene catalysis
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(Matrix presented) Bulky phenanthracenyl imidazolium-derived carbene ligands were investigated for copper-free Sonogashira coupling with terminal acetylenes. Aryl bromides and iodides gave coupled products in excellent yields from the Pd(PPh3)2Cl2 complex with potassium t-butoxide and 18-crown-6 in THF. A remarkable dependence on the size of the ligand was found. The highest yields were obtained with the bulky 2,9-dicyclohexyl-10-phenanthryl ligand 5.
- Ma, Yudao,Song, Chun,Jiang, Wei,Wu, Quansheng,Wang, Yong,Liu, Xueying,Andrus, Merritt B.
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p. 3317 - 3319
(2007/10/03)
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- Efficient and General Protocol for the Copper-Free Sonogashira Coupling of Aryl Bromides at Room Temperature
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(Equation presented) A mild and general protocol for the copper-free Sonogashira coupling of aryl bromides with acetylenes has been developed. The use of (AllylPdCl)2 and P(t-Bu)3 provides the active Pd(0) catalyst that allows subseq
- Soheili, Arash,Albaneze-Walker, Jennifer,Murry, Jerry A.,Dormer, Peter G.,Hughes, David L.
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p. 4191 - 4194
(2007/10/03)
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- Pd-catalyzed cross-coupling of alkynylsilanols with iodobenzenes
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Alkynylsilanols were efficiently coupled with iodobenzene derivatives by a Pd catalyst in the presence of TBAF, and the corresponding substituted alkynes could be obtained in good to excellent yields.
- Chang, Sukbok,Yang, Soon Ha,Lee, Phil Ho
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p. 4833 - 4835
(2007/10/03)
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- Generation of cycloalkylidene carbenes via exo-type cyclization of alkynyllithiums bearing remote leaving group
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The reaction of 5-hexynyl rosylate (3a) with alkynyllithium (RC≡CLi; R = Ph, TMS) gives enynes 5 and 6. The reaction proceeds through a mechanism involving a novel exo-type cyclization of 6-lithio-5-hexynyl tosylate to form cyclopentylidene carbene. Enyne 6 is produced by the addition of RC≡CLi to the carbene, whereas rearrangement of the carbene to cyclohexyne followed by carbolithiation with RC≡CLi gives enyne 5. The formation of cyclopentylidene carbene and cyclohexyne as intermediates is clearly demonstrated by trapping experiments with cyclohexene (and triethylsilane) and with 1,3- diphenylisobenzofuran, respectively. Alkynyllithiums derived from 3-butynyl and 6-heptynyl p-fluorobenzenesulfonates (19a,b) undergo a similar exo-type cyclization to give cyclopropylidene and cyclohexylidene carbenes, respectively.
- Harada, Toshiro,Iwazaki, Katsuhiro,Otani, Takeshi,Oku, Akira
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p. 9007 - 9012
(2007/10/03)
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- Dehydration-hydration of α-alkynols over zeolite catalyst. Selective synthesis of conjugated enynes and α,β-unsaturated ketones
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α-Alkynols 1 are convened in high yield and selectivity into conjugated enynes 2 or α,β-unsaturated ketones 3 by treatment with acid zeolites. The exclusive production of compounds 2 or 3 depends on the nature of the starting material 1 and experimental conditions.
- Sartori, Giovanni,Pastorio, Andrea,Maggi, Raimondo,Bigi, Franca
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p. 8287 - 8296
(2007/10/03)
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- Diastereoselective syn or anti opening of propargylic epoxides. Synthesis of α-allenic alcohols
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Propargylic epoxides easily react with Grignard reagents and catalytic amounts of copper(I) salt to afford α-allenic alcohols. The reaction is highly diastereoselective and its stereochemical outcome (syn or anti isomer) can be fully controlled. The syn d
- Alexakis,Marek,Mangeney,Normant
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p. 1677 - 1696
(2007/10/02)
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