- Total synthesis of chiral falcarindiol analogues using BINOL-Promoted alkyne addition to aldehydes
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An enantioselective total synthesis of chiral falcarindiol analogues from buta-1,3-diyn-1- yltriisopropylsilane is reported. The key step in this synthesis is BINOL-promoted asymmetric diacetylene addition to aldehydes. The two chiral centers of the falcarindiol analogues can be produced by using the same kind of catalyst with high selectivity, and the final product can be obtained in only six steps.
- Li, Wang,Ping-Ping, Shou,Si-Ping, Wei,Chun, Zhang,Shuang-Xun, Li,Ping-Xian, Liu,Xi, Du,Qin, Wang
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- A general strategy toward the total synthesis of C17 polyacetylenes virols A and C
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A general strategy toward the total synthesis of biologically important C17 polyacetylenes family such as virols A and C has been developed, which employed the (R, R)-ProPhenol/Zn complex-catalyzed highly stereoselective direct addition of propiolate to aliphatic aldehydes as the key step for constructing chiral (S)-alkynol units. Besides, chiral alkynol units in other C17 polyacetylenes were also synthesized based on the protocol developed.
- Liu, Jia,Li, Hong-Lian,Guo, Xian-Ru,Zhou, Lin,Wang, Yi,Duan, Ya-Nan,Wang, Mei-Zi,Na, Ri-Song,Yu, Bin
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- Synthesis, Anticancer Activity, Structure-Activity Relationship and Mechanistic Investigations of Falcarindiol Analogues
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Forty samples of optically active falcarindiol analogues are synthesized by using the easily available C2 symmetric (R)- and (S)-1,1’-binaphth-2-ol (BINOL) in combination with Ti(OiPr)4, Zn powder and EtI. Their anticancer activities on Hccc-9810, HepG2, MDA-MB-231, Hela, MG-63 and H460 cells are assayed to elucidate their structure-activity relationships. These results showed that the falcarindiol analogue (3R,8S)-2 i with the terminal double bond has the most potent anti-proliferation effect on Hccc-9810 cells with IC50 value of 0.46 μM. The falcarindiol analogue (3R,8S)-2 i can induce obvious Hccc-9810 cell apoptosis in a concentration-dependent manner by Hoechst staining and flow cytometry analysis. The proposed mechanism suggests that the falcarindiol analogue (3R,8S)-2 i increases LDH release and MDA content, and reduces the levels of SOD activity, which lead to the accumulation of oxidative stress and induce apoptosis in Hccc-9810 cells.
- Tan, Wan-Li,Zhang, Chun,Li, Yang,Guo, Kai,Gao, Xiao-Wei,Wei, Jun,Yi, Dong,Pu, Lin,Wang, Qin
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- Alkene Difunctionalization Triggered by a Stabilized Allenyl Radical: Concomitant Installation of Two Unsaturated C?C Bonds
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Radical-mediated difunctionalization of alkenes provides a promising approach to introduce one alkenyl or alkynyl group to target compounds. However, simultaneous installation of two unsaturated C?C bonds via alkene difunctionalization remains elusive, at
- Wei, Yunlong,Wu, Xinxin,Zhang, Hong,Zhu, Chen
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supporting information
p. 20215 - 20219
(2021/08/03)
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- Synthesis and Biological Evaluation of Falcarinol-Type Analogues as Potential Calcium Channel Blockers
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A series of enantiomers of falcarinol analogues (2) were synthesized using a chiral 1,1′-binaphth-2-ol (BINOL)-based catalytic system. The neuroprotective effects of falcarinol (1a) and its analogues (2) on PC12 cells injured by sodium azide (NaN3) were investigated. The structure-function relationships and possible mechanism were studied. Pretreatment of PC12 cells with falcarinol analogues (R)-2d and (R)-2i for 1 h following addition of NaN3 and culture in a CO2 incubator for 24 h resulted in significant elevation of cell viability, as determined by a CCK-8 assay and Hoechst staining, with reduction of LDH release and MDA content, increase of SOD activity, and decrease of ROS stress, when compared with the activity of natural falcarinol (1a). These observations indicated that the falcarinol analogues (R)-2d and (R)-2i can protect PC12 cells against NaN3-induced apoptosis via increasing resistance to oxidative stress. For the first time, falcarinol (1a) and its analogue (R)-2i were found to have potential L-type calcium channel-blocking activity, as recorded using a manual patch clamp technique on HEK-293 cells stably expressing hCav1.2 (α1C/β2a/α2δ1). These findings suggest that the mechanism of the L-type calcium channel-blocking activity of falcarinol (1a) and its analogue (R)-2i might be involved in neuroprotection by falcarinol-type analogues by inhibiting calcium overload in the upstream of the signaling pathway.
- Li, Yang,Tan, Wan-Li,Guo, Kai,Gao, Xiao-Wei,Wei, Jun,Yi, Dong,Zhang, Chun,Wang, Qin
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supporting information
p. 2138 - 2148
(2021/08/20)
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- Discovery of Novel Inhibitors of LpxC Displaying Potent in Vitro Activity against Gram-Negative Bacteria
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UDP-3-O-((R)-3-hydroxymyristoyl)-N-glucosamine deacetylase (LpxC) is as an attractive target for the discovery and development of novel antibacterial drugs to address the critical medical need created by multidrug resistant Gram-negative bacteria. By using a scaffold hopping approach on a known family of methylsulfone hydroxamate LpxC inhibitors, several hit series eliciting potent antibacterial activities against Enterobacteriaceae and Pseudomonas aeruginosa were identified. Subsequent hit-to-lead optimization, using cocrystal structures of inhibitors bound to Pseudomonas aeruginosa LpxC as guides, resulted in the discovery of multiple chemical series based on (i) isoindolin-1-ones, (ii) 4,5-dihydro-6H-thieno[2,3-c]pyrrol-6-ones, and (iii) 1,2-dihydro-3H-pyrrolo[1,2-c]imidazole-3-ones. Synthetic methods, antibacterial activities and relative binding affinities, as well as physicochemical properties that allowed compound prioritization are presented. Finally, in vivo properties of lead molecules which belong to the most promising pyrrolo-imidazolone series, such as 18d, are discussed.
- Surivet, Jean-Philippe,Panchaud, Philippe,Specklin, Jean-Luc,Diethelm, Stefan,Blumstein, Anne-Catherine,Gauvin, Jean-Christophe,Jacob, Lo?c,Masse, Florence,Mathieu, Ga?lle,Mirre, Azely,Schmitt, Christine,Lange, Roland,Tidten-Luksch, Naomi,Gnerre, Carmela,Seeland, Swen,Herrmann, Charlyse,Seiler, Peter,Enderlin-Paput, Michel,Mac Sweeney, Aengus,Wicki, Micha,Hubschwerlen, Christian,Ritz, Daniel,Rueedi, Georg
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supporting information
p. 66 - 87
(2020/01/09)
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- Chiral falcarinol analog, synthesis method and application thereof
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The present invention relates to a chiral falcarinol analog, a synthesis method and application thereof. The chiral falcarinol analog has a structural formula I as shown below. Diastereoselective addition is performed on aldehyde of a terminal 1,3-diyne c
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Paragraph 0062; 0063; 0064
(2019/02/04)
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- Fakalin alcohol compound enantiomer, method for synthesizing same and application of Fakalin alcohol compound enantiomer
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The invention relates to a Fakalin alcohol compound enantiomer, a method for synthesizing the same and application of the Fakalin alcohol compound enantiomer. Structural general formulas of the Fakalin alcohol compound enantiomer are shown as formulas I a
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Paragraph 0045; 0046; 0047
(2019/01/23)
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- One-pot synthesis of unsymmetrical 1,3-butadiyne derivatives and their application in the synthesis of unsymmetrical 2,5-diarylthiophenes
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A one-pot protocol was developed for the synthesis of unsymmetrical 1,3-butadiynes. The procedure is based on two sequential reactions: deprotection of R–C≡C–C≡C– C(Me)2OH derivatives in a retro-Favorskii reaction to furnish a terminal 1,3-butadiyne compound, which reacted with aryl iod-ides in a Sonogashira-type cross-coupling reaction catalyzed by Pd(PPh3)4 and CuI, using TBAOH as activator and toluene as solvent under reflux for 10 min. We also studied in situ thiocycli-zation of 1,3-butadiynes, leading to unsymmetrical 2,5-diaryl-thiophenes. The principal features of this method are operational simplicity, good substrate scope, very fast reaction, and high yields.
- Andrade, Camila B.,Carvalho, Diego B.,Trefzger, Ozildéia S.,Kassab, Najla M.,Guerrero, Palimécio G.,Barbosa, Sandro L.,Shiguemoto, Cristiane Y. K.,Baroni, Adriano C. M.
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supporting information
p. 696 - 704
(2019/01/04)
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- Synthesis of α-Acyloxy-α′-hydroxy Ketones via Cyclic Carbonate Intermediates Generated from Tertiary Bromopropargylic Alcohols and Cs2CO3
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A facile approach towards α-acyloxy-α′-hydroxy ketones by reaction of readily available tertiary bromopropargylic alcohols and carboxylic acids in system Cs2CO3/H2O/DMF (50–55 °C, 4 h) was developed. Key intermediates of this synthesis are cyclic carbonates generated in situ from bromopropargylic alcohols and Cs2CO3 which have been utilized as both reagent and base promoter.
- Shemyakina, Olesya A.,Volostnykh, Ol'ga G.,Stepanov, Anton V.,Ushakov, Igor' A.
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supporting information
p. 7117 - 7121
(2019/11/16)
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- De Novo Ring-Forming Consecutive Four-Component Syntheses of 4-Pyrazolyl-1,2,3-triazoles from (Triisopropylsilyl)butadiyne as a C4 Building Block
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4-Pyrazolyl-1,2,3-triazoles can be readily synthesized in a one-pot fashion and moderate yield by employing a consecutive four-component process consisting of a sequentially Pd-Cu-catalyzed alkynylation-cyclocondensation-desilylation-CuAAC process. Most distinctly, (triisopropylsilyl)butadiyne is employed as a four-carbon building block in this one-pot de novo formation of both heterocyclic moieties.
- Niesobski, Patrik,Klukas, Fabian,Berens, Henning,Makhloufi, Gamall,Janiak, Christoph,Müller, Thomas J. J.
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p. 4851 - 4858
(2018/04/26)
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- Highly Selective Manganese(I)/Lewis Acid Cocatalyzed Direct C?H Propargylation Using Bromoallenes
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A manganese(I)/Lewis acid cocatalyzed direct C?H propargylation with high selectivity has been developed. BPh3 was discovered to not only promote the reactivity, but also enhance the selectivity. Secondary, tertiary, and even quaternary carbon centers at the propargylic position could be directly constructed. Both internal and terminal alkynes are easily accessible. The chirality was successfully transferred from an axially chiral allene to central chirality. The reactivity of the manganese catalyst in this reaction was found to be unique among transition metal catalysts.
- Zhu, Can,Schwarz, Jonas Luca,Cembellín, Sara,Gre?ies, Steffen,Glorius, Frank
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supporting information
p. 437 - 441
(2018/02/21)
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- An efficient heterogeneous palladium(0)-catalysed cross-coupling between 1-bromoalkynes and terminal alkynes leading to unsymmetrical 1,3-diynes
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An efficient heterogeneous palladium(0)-catalysed cross-coupling of 1-bromoalkynes with terminal alkynes was achieved in DMF at room temperature in the presence of 5 mol% of MCM-41-immobilised bidentate phosphine palladium(0) complex [MCM-41-2P-Pd(0)] and 2 mol% of CuI with Et3N as base, yielding a variety of unsymmetrical 1,3-diynes in moderate to good yields. This heterogeneous palladium(0) complex could be easily recovered by a simple filtration of the reaction solution and recycled at least seven times without significant decrease in activity.
- Xu, Zhaotao,Ai, Jinting,Cai, Mingzhong
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p. 133 - 137
(2018/04/20)
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- A Highly Regio- and Stereoselective Syntheses of α-Halo Enamides, Vinyl Thioethers, and Vinyl Ethers with Aqueous Hydrogen Halide in Two-Phase Systems
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A metal-free regio- and stereoselective method is achieved for the preparation of (E)-configured α-halo enamides, vinyl thioethers, and vinyl ethers using aqueous HX (X = F, Cl, Br, I), which features high functional group compatibility and regio- and stereoselectivity, mild conditions, high efficiency, and rapid transformation. Additionally, the isomers could be yielded readily from the (E)-configured α-halo enamides via photocatalysis or under Sonogashira coupling conditions.
- Cao, Wei,Chen, Ping,Wang, Liang,Wen, Hao,Liu, Yu,Wang, Wanshu,Tang, Yu
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supporting information
p. 4507 - 4511
(2018/08/09)
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- Synthesis and Utility of 2,2-Dimethyl-2 H-pyrans: Dienes for Sequential Diels-Alder/Retro-Diels-Alder Reactions
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The practical use of 2,2-dimethyl-2H-pyrans as electron-rich dienes in sequential Diels-Alder/retro-Diels-Alder (DA/rDA) domino processes to generate aromatic platforms has been demonstrated. Different polysubstituted alkyl 2-naphthoates have been synthesized by the DA/rDA reaction of benzynes and 2,2-dimethyl-2H-pyrans. The use of other activated alkynes allows the access of substituted alkyl benzoate derivatives.
- Tejedor, David,Díaz-Díaz, Abián,Diana-Rivero, Raquel,Delgado-Hernández, Samuel,García-Tellado, Fernando
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supporting information
p. 7987 - 7992
(2019/01/04)
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- Method for synthesizing chiral falcarindiol analogues
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The invention relates to a method for synthesizing chiral falcarindiol analogues. The method includes the steps that an asymmetric addition reaction is performed on aldehyde two times at 0-25 DEG C through a butadiyne compound under the catalysis of a BIN
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Paragraph 0025
(2017/01/17)
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- Highly enantioselective copper(i)-catalyzed conjugate addition of 1,3-diynes to α,β-unsaturated trifluoromethyl ketones
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The conjugate diynylation of α,β-unsaturated trifluoromethyl ketones is carried out in the presence of a low catalytic load (2.5 mol%) of a copper(i)-MeOBIPHEP complex, triethylamine and a terminal 1,3-diyne. Pre-metalation of the terminal 1,3-diyne with stoichiometric or higher amounts of dialkylzinc reagent is not required. The corresponding internal diynes bearing a propargylic stereogenic center are obtained with good yields and excellent enantioselectivities. This journal is
- Sanz-Marco, Amparo,Blay, Gonzalo,Mu?oz, M. Carmen,Pedro, José R.
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supporting information
p. 8958 - 8961
(2015/05/27)
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- Copper-catalyzed three-component synthesis of 3-Aminopyrazoles and 4-iminopyrimidines via β-alkynyl-N-sulfonyl ketenimine intermediates
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3-Aminopyrazoles and 4-iminopyrimidines were efficiently prepared via copper-catalyzed three-component reactions of butadiynes, sulfonylazides, and hydrazides or imidamides. The reactions were regioselectively approached via the formation of a β-alkynyl-N-sulfonyl ketenimine intermediate which represented a new and effective 1,3-dielectrophilic equivalent in organic synthesis.
- Xing, Yanpeng,Cheng, Binyu,Wang, Jing,Lu, Ping,Wang, Yanguang
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supporting information
p. 4814 - 4817
(2015/04/27)
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- Palladium-catalyzed bond reorganization of 1,3-diynes: An entry to diverse functionalized 1,5-dien-3-ynes
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A mild and efficient method for the synthesis of functionalized 1,5-dien-3-ynes from 1,3-diynes under PdII catalysis is described. The process allows quick and atom-economical assembly of various dihalo-, haloacyl-, and diacyl-substituted 1,5-dien-3-ynes in high yields. The switch of selectivity in the formation of these dienyne products can be controlled by the choice of catalysis system and reaction conditions.
- Wu, Wanqing,Gao, Yang,Jiang, Huanfeng,Huang, Yubing
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supporting information
p. 4580 - 4586
(2013/06/05)
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- Asymmetric addition of arylboronic acids to cumulene derivatives catalyzed by axially chiral N-heterocyclic carbene-Pd2+ Complexes
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Cumulene+carbene=chirality! Asymmetric additions of boronic acids to cumulene derivatives, catalyzed by an N-heterocyclic carbene-palladium complex, provide the desired allenic products in good to excellent yields and moderate to good enantioselectivities
- Liu, Zhen,Gu, Peng,Shi, Min
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supporting information; experimental part
p. 5796 - 5799
(2011/06/26)
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- Polyunsaturated alkyl amides from echinacea: Synthesis of diynes, enynes, and dienes
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The synthesis of 20 alkyl amides, including 15 naturally occurring polyunsaturated alkyl amides previously identified from Echinacea spp. (1-13 and 62) or from Achilla sp. (55) and five previously unknown geometric isomers (23, 28, 67, 73, and 80), is described. Importantly, these amides include all of the major alkyl amides present in commercially used Echinacea extracts. The syntheses demonstrate methodology used for constructing alkyl amides containing conjugated diyne and isomerically pure enyne and diene moieties and may be adapted easily for the preparation of other alkyl amides present in Echinacea spp. Terminal-conjugated diynes were prepared by a Cadiot-Chodkiewitz coupling/deprotection sequence utilizing a protected bromoacetylene, and methyl-substituted diynes were made via a base-catalyzed rearrangement of terminal-skipped diynes. Conjugated dienes were prepared conveniently and with high stereoselectivity by the reduction of enynes or diynes with Rieke zinc. With the exception of 1-2 and 11-12, the alkyl amides are synthesized here for the first time, and their NMR data are consistent with that of the reported isolated natural compounds.
- Matovic, Nicholas J.,Hayes, Patricia Y.,Penman, Kerry,Lehmann, Reginald P.,De Voss, James J.
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scheme or table
p. 4467 - 4481
(2011/07/30)
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- From highly enantioselective catalytic reaction of 1,3-diynes with aldehydes to facile asymmetric synthesis of polycyclic compounds
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(S)-1,1′-Binaphth-2-ol (BINOL) in combination with ZnEt2, Ti(OiPr)4, and biscyclohexylamine was found to catalyze the highly enantioselective (83-95% ee) addition of various 1,3-diynes to aldehydes of diverse structures. This method provides a convenient pathway to generate a number of optically active dienediynes as the acyclic precursors to polycyclic compounds. The chiral dienediynes undergo highly chemoselective Pauson-Khand (PK) cycloaddition in benzaldehyde by using [Rh(cod)Cl]2 as the catalyst in the presence of rac-BINAP. High diastereoselectivity (up to >20:1) has also been achieved with the chiral dienediyne substrates containing a bulky substituent adjacent to the chiral center. In the presence of the Grubbs II catalyst, ring-closing enyne metathesis of the PK cycloaddition products led to the formation of the desired 5,5,7- and 5,5,8-fused tricyclic compounds. Further highly diastereoselective Diels-Alder reaction of a 5,5,7-tricyclic compound with maleic anhydride produced a 5,5,7,6-polycyclic product. The asymmetric synthesis of polycyclic compounds from optically active dienediynes has established a novel and efficient synthetic route to the structural framework of many biologically significant molecules.
- Turlington, Mark,Du, Yuhao,Ostrum, Samuel G.,Santosh, Vishaka,Wren, Kathryne,Lin, Tony,Sabat, Michal,Pu, Lin
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supporting information; experimental part
p. 11780 - 11794
(2011/09/16)
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- Enantioselective prophenol-catalyzed addition of 1,3-diynes to aldehydes to generate synthetically versatile building blocks and diyne natural products
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A highly enantioselective method for the catalytic addition of terminal 1,3-diynes to aldehydes was developed using our dinuclear zinc ProPhenol (1) system. Furthermore, triphenylphosphine oxide was found to interact synergistically with the catalyst to substantially enhance the chiral recognition. The generality of this catalytic transformation was demonstrated with aryl, α,β-unsaturated and saturated aldehydes, of which the latter were previously limited in alkynyl zinc additions. The chiral diynol products are also versatile building blocks that can be readily elaborated; this was illustrated through highly selective trans-hydrosilylations, which enabled the synthesis of a β-hydroxyketone and enyne. Additionally, the development of this method allowed for the rapid total syntheses of several biologically important diynol-containing natural products.
- Trost, Barry M.,Chan, Vincent S.,Yamamoto, Daisuke
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supporting information; experimental part
p. 5186 - 5192
(2010/06/19)
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- Expedient synthesis of functionalized conjugated enynes: Palladium-catalyzed bromoalkynylation of alkynes
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(Chemical Equation Presented) Side by side: Direct cis addition of bro-moalkynes 1 to various alkynes 2 was found to proceed in the presence of a PdII catalyst to give difunctionalized enyne products 3. The method is facile for the synthesis of bromo alkenynes. Further-more, an unusual mechanism is pro-posed.
- Li, Yibiao,Liu, Xiaohang,Jiang, Huanfeng,Feng, Zhenning
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supporting information; experimental part
p. 3338 - 3341
(2010/07/10)
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- A domino reaction of α,β-acetylenic λ-hydroxy nitriles with arenecarboxylic acids: An unexpected facile shortcut to 4-cyano-3(2 H)-furanones
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(Figure Presented) An unexpected facile domino reaction of α,β-acetylenic λ-hydroxy nitriles with arenecarboxylic acids (Et3N, MeCN, 20-25 °C, 48 h) affords 4-cyano-3(2H)-furanones in 67-86% yield. The reaction is triggered by the addition of a
- Trofimov, Boris A.,Shemyakina, Olesya A.,Malkina, Anastasiya G.,Ushakov, Igor A.,Kazheva, Olga N.,Alexandrov, Grigorii G.,Dyachenko, Oleg A.
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scheme or table
p. 3200 - 3203
(2010/10/03)
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- Chemo-and regiospecific modification of D,L-tryptophan by reaction with α,β-acetylenic γ-hydroxy nitriles
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D,L-Tryptophan reacts with α,β-acetylenic γ-hydroxy nitriles, chemo-and regiospecifically, under mild, green conditions via a hydroamination-type process involving the primary amine group. The hydroxycyanopropanyl substituent of the initial adducts underg
- Trofimov, Boris A.,Malkina, Anastasiya G.,Borisova, Angela P.,Shemyakina, Olesya A.,Nosyreva, Valentina V.,Albanov, Alexander I.
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scheme or table
p. 3174 - 3178
(2010/10/21)
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- Highly efficient two-step synthesis of (Z)-2-halo-1-iodoalkenes from terminal alkynes
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The easily accessible haloalkynes can be converted to (Z)-2-halo-1- iodoalkenes in high yields with excellent regio- and stereoselectivity. The method shows good functional group compatibility. The resulting products could find broad applications.
- Chen, Zhengwang,Jiang, Huanfeng,Li, Yibiao,Qi, Chaorong
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supporting information; experimental part
p. 8049 - 8051
(2011/01/03)
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- Weak interactions dominating the supramolecular self-assembly in a salt: A designed single-crystal-to-single-crystal topochemical polymerization of a terminal aryldiacetylene
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Single-crystal-to-single-crystal (SCSC) topochemical polymerizations of diacetylenes can yield nearly defect-free conjugated polymer crystals unattainable by other methods. Aryl-substituted diacetylenes with their potentially greater conjugation have been targeted for years, but until now no one has reported a SCSC polymerization of any aryl-substituted diacetylene. This is presumably due to the rigidity of such diaryl-substituted monomers as well as the lack of control over the supramolecular structure. To address this problem, the polymerization of a terminal phenyldiacetylene was targeted. It was assumed that a terminal diacetylene should demonstrate greater flexibility in the solid state. To establish the necessary (~4.9 A) repeat distance, commensurate with the repeat distance in the polymer, a host-guest system was designed. The chosen diacetylene guest, the amine DABzNH2, was to be crystallized with the oxalamide dicarboxylic acid host, H2og. The plan required a segregation of the hydrogen bonds, amide-amide hydrogen bonds to establish the 4.9 A spacing, and the carboxylate to ammonium ion hydrogen bonds to organize the guest. Prior to carrying out the diacetylene synthesis a series of model salts were studied. Consistent with the hydrophobic effect it was found that amines with large "greasy" substituents assembled according to the design. Once the model studies established that weak interactions could dominate the supramolecular structure of a salt, the actual design was put to the test. The targeted guest, DABzNH2, was synthesized and crystals of the host-guest salt (DABzNH3) 2og were prepared. The resulting crystal structure was in complete accordance with the design. A SCSC polymerization was achieved by a slow annealing treatment lasting about three months. The crystal structure of the resulting polymer not only confirmed the first example of a poly(aryldiacetylene) single crystal, it also revealed an unexpected reaction pathway that shows a major movement involving the rigid aromatic substituent.
- Li, Zhong,Fowler, Frank W.,Lauher, Joseph W.
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supporting information; experimental part
p. 634 - 643
(2009/06/18)
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- Bulky trialkylsilyl acetylenes in the Cadiot-Chodkiewicz cross-coupling reaction
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Bulky trialkylsilyl-protected alkynes such as triethylsilyl (TES), tert-butyldimethylsilyl (TBS), and tri-isopropylsilyl (TIPS) acetylenes underwent the Cadiot-Chodkiewicz cross-coupling reaction with different bromoalkynes to form a variety of synthetically useful unsymmetrical diynes in good yields. The diyne alcohol 10 was transformed regio- and stereoselectively into enynes by hydrotelluration, carbometalation, and reduction reactions.
- Marino, Joseph P.,Nguyen, Hanh Nho
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p. 6841 - 6844
(2007/10/03)
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- Synthesis of (Z)-1-phenylseleno-1,4-diorganyl-1-buten-3-ynes: Hydroselenation of symmetrical and unsymmetrical 1,4-diorganyl-1,3-butadiynes
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The hydroselenation of 1-organyl-1,3-butadiynes and 1,4-diorganyl-1,3-butadiynes with the sodium phenylselenolate anion, which was generated in situ by reacting diphenyl diselenide with NaBH4 in aqueous ethanol, results in the regio-, stereo- and chemoselective formation the 1-phenylseleno-4-organyl-1-buten-3-ynes and 1-phenylseleno-1,4-diorganyl-1-buten-3-ynes of Z configuration respectively. The lack of selectivity with the 2-hydroxy-2-methyl-3,5-dodecadiyne was observed and the obtained product structures were studied in detail.
- Dabdoub, Miguel J.,Baroni, Adriano C.M.,Lenard?o, Eder J.,Gianeti, Thiago R.,Hurtado, Gabriela R.
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p. 4271 - 4276
(2007/10/03)
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- 1-Halo-1-acceptor-/1,1-diacceptor-substituted allenes, 9: Functionalized allenes, haloallenes, and bisallenes via [2,3]/[3,3]-sigmatropic rearrangements and their reactivity
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Reaction of carbonyl compounds 1 with trimethylsilylacetylene 2 leads to the alkynols 3, which are excellent precursors of acceptor-substituted allenes. Compound 3 reacts with carbamoyl chloride 4, diethyl chlorophosphate 6, or hypohalite 8 to give the substituted alkynols 5, 7, 9. Reaction of 9 with sulfinyl chloride 10 leads to the sulfinic esters 11, which on heating undergo a [2,3]-sigmatropic shift to yield the halosulfonyl allenes 12. In the same manner the reaction of 7 and 9 with chlorophosphanes 13 or sulfenyl chlorides 15 gives rise to the generation of the phosphoryl allenes 14 and the haloallenyl sulfoxides 16, respectively. Alkynyl ketene acetal intermediates 18 are formed by starting from the alkynols 9 and orthoesters 17. Spontaneous [3,3]-sigmatropic rearrangement of 18 gives the haloallenyl esters 19. Reaction of alkynols 5 with sulfur dichloride leads to the alkynylsulfinyl esters 20, which on heating rearrange to the bisallenyl sulfones 21. Pyrolysis of 21 yields the thiophene 1,1-dioxides 22. Bisphosphorylbisallene 24 is synthesized from hexadiyndiol 23 by reaction with chlorodiethoxyphosphite. Halophosphoryl allenes 14 react with bromine to yield the oxaphospholenes 25 by cyclization and subsequent elimination of ethanol, or oxaphospholenes 26, if no appropriate leaving group is present in the molecule. Sulfonyl-1,3-dienes 27 can be synthesized by reaction of halosulfonylallenes 12 with bromine, followed by elimination of HBr. Haloallenyl ester 19a is converted in a non-generalizable reaction with bromine into the tribromo3,6-dihydro-2-pyranone 30. VCH Verlagsgesellschaft mbH, 1996.
- Saalfrank, Rolf W.,Welch, Andreas,Haubner, Martin,Bauer, Udo
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p. 171 - 181
(2007/10/03)
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- Unsaturated ester-amides of halogenated alkenes
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This invention deals with new unsaturated ester-amides of α,β-unsaturated polycarboxylic acids derived from halogenated alcohols of the formula EQU1 wherein R is a divalent hydrocarbon moiety having at least one and no more than 10 carbon atoms, X is a member selected from the class of bromine and chlorine, and R' is a member selected from the class of hydrogen and a monovalent hydrocarbon containing at least one and no more than 20 carbon atoms. Typical ester-amides are the maleates, fumarates, itaconates and citraconates. These monomers possess fire-retardant properties and are useful for the synthesis of polymers and copolymers.
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