- Syntheses and characterizations of Zn (Ⅱ) Phthalocyanines & Naphthopyrans based polymers for improved nonlinear optical properties
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In this paper, four organic polymers of poly [(MMA)x-co-(NPMA)y-co-(CPMA)z] and four zinc phthalocyanine (ZnPc) polymers of poly [(MMA)x-co-(NPMA)y-co-(ZnPc)z] have been successfully synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, where MMA is methyl methacrylate, NPMA is 3,3-diphenyl-8-methacryloxy-3H-naphtho [2,1-b]pyran, and CPMA is 3,4-dicyanophenyl methacrylate. The components of these polymers have been fully characterized by 1H and 13C NMR, FT-IR, Raman, XPS, UV–Vis, and photoluminescence (PL) spectroscopy. From PL spectra, poly [(MMA)x-co-(NPMA)y-co-(ZnPc)z] polymers display strong fluorescence quenching by the energy transfer (ET) process between NPMA and ZnPc moieties. The third-order nonlinear optical (NLO) properties of poly [(MMA)x-co-(NPMA)y-co-(ZnPc)z] polymers have been investigated by the Z-scan technique, and poly [(MMA)168-co-(NPMA)5.2-co-(ZnPc)1.2] (Q4) showed the best NLO properties owing to the much stronger ET between NP and ZnPc units. Furthermore, it is essential to obtain doped poly (methyl methacrylate) (PMMA) films for practical application. The poly [(MMA)168-co-(NPMA)5.2-co-(ZnPc)1.2]/PMMA film exhibited a higher nonlinear absorption coefficient of 61 × 10?11 m/W and a lower limiting threshold of 0.19 J/cm2. The significantly enhanced NLO properties of poly [(MMA)168-co-(NPMA)5.2-co-(ZnPc)1.2]/PMMA film compared with solution are attributed to the weaker aggregation effect in PMMA film. This research provides a promising molecular design strategy for high performance NLO materials.
- Dong, Wenyue,Duan, Qian,Gao, Bo,Liu, Dajun,Wang, Jihua
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Read Online
- Preparation of anthranilsviachemoselective oxidative radical cyclization of 3-(2-azidoaryl) substituted propargyl alcohols
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In the presence of K2S2O8and HOAc, 3-(2-azidoaryl) substituted propargyl alcohols can go through chemoselective oxidative radical cyclizations to give a pool of anthranils based on Meyer-Schuster rearrangement. It's proposed that the cyclizations were triggered exclusively by the direct attack of oxygen radicals on the azides. The weak N-O bonds in anthranils could be easily cleaved in the presence of transition metal catalysts and went through aminations with 2-oxo-2-phenylacetic acid and iodobenzene.
- Gao, Chao,Xu, Jian,Zhu, Shuxian,Jian, Kaixia,Xuan, Qingqing,Song, Qiuling
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Read Online
- Fluorocyclization of Allyl Alcohols and Amines to Access 3-Functionalized Oxetanes and Azetidines
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An efficient method to prepare 3-functionalized oxetanes and azetidines has been realized by fluorocyclization of readily available 2-azidoallyl/2-alkoxyallyl alcohols and amines. Notably, this is the first example applying the fluorocyclization strategy to construct four-membered heterocycles. The pendant electron-donating group (-N3 or -OR) plays a crucial role in polarizing the C= C double bond and facilitating the cyclization process, as verified by DFT and experimental studies.
- Cao, Shanshan,Li, Linxuan,Liu, Zhaohong,Ning, Yongquan,Wu, Yong,Zanoni, Giuseppe,Zhang, Qi,Zhang, Xinyu
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supporting information
p. 3674 - 3679
(2021/05/31)
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- Development of Axially Chiral Styrene-Type Carboxylic Acid Ligands via Palladium-Catalyzed Asymmetric C-H Alkynylation
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A weakly coordinated carboxylate-directed palladium-catalyzed atroposelective C-H alkynylation method for the development of novel axially chiral styrene-type carboxylic acids is disclosed. This transformation exhibits good yields (up to 85%), excellent enantiocontrol (up to 99% ee), and mild conditions. Notably, the synthetic utility of the resulting alkynyl carboxylic acid derivatives was demonstrated by various derivatizations as well as their potential as chiral ligands in asymmetric C-H activations.
- Cui, Ru,Jin, Ruo-Xing,Li, Fei,Li, Yan,Wang, Xi-Sheng,Wu, Bing-Bing,Wu, Tian-Rui,Yang, Chi
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supporting information
p. 8132 - 8137
(2021/11/01)
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- Calcium-Catalyzed Intramolecular Hydroamination-Deacylation Reaction of in situ formed β-Amino Allenes
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We have developed a simple, One-Pot, three-component reaction of tert-propargyl alcohols, primary amines and acyl ketones to synthesize fully substituted pyrroles and pyridine derivatives in good to excellent yields with large substrate diversity. An eco-friendly calcium catalyst catalyzes the reaction to form the key intermediate β-amino allene that undergoes subsequent Thorpe-Ingold effect assisted hydroamination and aromaticity driven deacylation reaction to yield fully substituted five and six-membered azacyclic compounds. (Figure presented.).
- Yaragorla, Srinivasarao,Latha, Dandugula Sneha,Rajesh, Pallava
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supporting information
p. 5486 - 5492
(2021/12/10)
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- Direct Exploitation of the Ethynyl Moiety in Calcium Carbide Through Sealed Ball Milling
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Ball milling of calcium carbide (CaC2) enables the reaction of its ethynyl moiety with organic electrophiles. This was realized simply by co-milling CaC2 with organic substrates in a sealed jar without the need for an additive or a catalyst. Various ketones including those bearing α-hydrogens were ethynylated in good yields at short reaction times. Aryl halides are also amenable substrates for this protocol as they furnish aryl ethynes through a benzyne intermediate. This method offers a practical and cheap alternative to the established procedures for introducing ethynyl functionalities.
- Hosseini, Abolfazl,Schreiner, Peter R.
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p. 4339 - 4346
(2020/07/04)
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- Transition-Metal-Free Radical Hydrotrifluoromethylation of Alkynes
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A combination of readily available and bench-stable CF3SO2Na and tBuOOH was efficiently used for hydrotrifluoromethylation of alkynes. An excellent trans-selectivity was demonstrated in the synthesis of alkenes. The developed mild reaction conditions allow the supression of the competing Meyer–Schuster-type rearrangement.
- Matcha, Kiran,Antonchick, Andrey P.
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supporting information
p. 309 - 312
(2019/01/24)
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- Mechanosynthesis of Odd-Numbered Tetraaryl[n]cumulenes
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A mechanochemical synthesis of one-dimensional carbon allotrope carbyne model compounds, namely tetraaryl[n]cumulenes (n=3, 5) was realized. Central for the mechanosynthesis of the cumulenic carbon nanostructures were the development of a mechanochemical Favorskii alkynylation-type reaction and the implementation of a solvent-free, acid-free reductive elimination with tin(II) chloride by ball milling.
- Ardila-Fierro, Karen J.,Bolm, Carsten,Hernández, José G.
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supporting information
p. 12945 - 12949
(2019/08/01)
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- Synthesis, Characterization, and Reactivity of Cationic Gold Diarylallenylidene Complexes
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Methoxide abstraction from gold acetylide complexes of the form (L)Au[η1-C≡CC(OMe)ArAr′] (L=IPr, P(tBu)2(ortho-biphenyl); Ar/Ar′=C6H4X where X=H, Cl, Me, OMe) with trimethylsilyl trifluoromethanesulfonate (TMSOTf) at ?78 °C resulted in the formation of the corresponding cationic gold diarylallenylidene complexes [(L)Au=C=C=CArAr′]+ OTf? in ≥85±5 % yield according to 1H NMR analysis. 13C NMR and IR spectroscopic analysis of these complexes established the arene-dependent delocalization of positive charge on both the C1 and C3 allenylidene carbon atoms. The diphenylallenylidene complex [(IPr)Au=C=C=CPh2]+ OTf? reacted with heteroatom nucleophiles at the allenylidene C1 and/or C3 carbon atom.
- Kim, Nana,Widenhoefer, Ross A.
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supporting information
p. 4722 - 4726
(2018/03/27)
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- Method for efficiently preparing alkynol
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The invention relates to a method for efficiently preparing alkynol, belongs to the field of preparation of chemical intermediates and chemicals, and particularly relates to a preparation method of alkynol. The preparation method comprises the following steps that 1, alkali metal is added into an anhydrous alcohols solvent; an alcohol-alkali metal solution is prepared; 2, a compound I is added into the alcohol-alkali metal solution; uniform stirring is performed; cooling is performed to be 0 DEG C or below; 3, acetylene is introduced through being metered at normal pressure; alkynol is obtained; 4, the alkynol solution after reaction is neutralized by ammonium chloride and a same alcohol mixed suspension system; 5, the neutralized mixed suspension system is filtered; after alcohols are recovered from filter liquid, reduced pressure distillation is performed to obtain an alkynol product. The method overcomes the defect that under the existing harsh reaction conditions of high pressure,liquid ammonia and the like, the solid potassium hydroxide feeding difficulty is avoided; under the ordinary pressure condition, the ketone compounds are converted into alkynol at high conversion rate. The method has the advantages of high conversion rate, simple process and good product purity.
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Paragraph 0036; 0037; 0038; 0043; 0044; 0045; 0046
(2018/12/14)
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- α-Hydroxy Ketones as Masked Ester Donors in Br?nsted Base Catalyzed Conjugate Additions to Nitroalkenes
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The catalyst-controlled enantioselective direct addition reaction of enolizable esters and related carboxylic acid derivatives to π electrophiles remains a difficult synthetic transformation. In this study, the suitability of α-hydroxy ketones as ester equivalents capable of being activated by bifunctional Br?nsted base catalysts in the context of conjugate addition reactions to nitroolefins is demonstrated. The scope of the reaction, which affords the corresponding Michael adducts with very high stereoselectivity (diastereomeric ratio (d.r.) ≥95:5, up to 99 % enantiomeric excess (ee)), and its limitations are explored, as is the aftermath elaboration of adducts into densely functionalized enantioenriched products.
- Olaizola, Iurre,Campano, Teresa E.,Iriarte, Igor,Vera, Silvia,Mielgo, Antonia,García, Jesús M.,Odriozola, José M.,Oiarbide, Mikel,Palomo, Claudio
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supporting information
p. 3893 - 3901
(2018/03/21)
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- Ni-Catalyzed regio- and stereoselective addition of arylboronic acids to terminal alkynes with a directing group tether
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Addition of arylboronic acids to directing group tethered acetylenes in a regio and stereoselective manner using an inexpensive catalytic system is achieved for the first time to access highly sought after allyl/homoallyl alcohol/amine units. The apparent vinylnickel intermediate was successfully trapped by the Michael electrophiles to get defined tri- and tetra-substituted olefins. An interesting selectivity switch was observed with internal alkynes.
- Hari Babu, Madala,Ranjith Kumar, Gadi,Kant, Ruchir,Sridhar Reddy, Maddi
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supporting information
p. 3894 - 3897
(2017/04/04)
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- Metal- and Acid-Free Methyl Triflate Catalyzed Meyer-Schuster Rearrangement
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A novel metal- and acid-free preparation of synthetically useful α,β-unsaturated carbonyl compounds from propargyl alcohols has been realized. This Meyer-Schuster rearrangement process is effectively catalyzed by methyl triflate (20 mol%) to prepare a broad scope of conjugated E -enals and E -enones generally in good to excellent yields (up to 90%). This reaction procedure operates under mild conditions (70 °C), in air, with short reaction times (1 h). Moreover, a carbocation intermediate trapped by the solvent 2,2,2-trifluoroethanol was isolated during this transformation.
- Yang, Lu,Zeng, Qingle
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p. 3149 - 3156
(2017/07/12)
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- Palladium(II)-Catalyzed Site-Selective C(sp3)?H Alkynylation of Oligopeptides: A Linchpin Approach for Oligopeptide–Drug Conjugation
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The palladium(II)-catalyzed C(sp3)?H alkynylation of oligopeptides was developed with tetrabutylammonium acetate as a key additive. Through molecular design, the acetylene motif served as a linchpin to introduce a broad range of carbonyl-containing pharmacophores onto oligopeptides, thus providing a chemical tool for the synthesis and modification of novel oligopeptide–pharmacophore conjugates by C?H functionalization. Dipeptide conjugates with coprostanol and estradiol were synthesized by this method for potential application in targeted drug delivery to tumor cells with overexpressed nuclear hormone receptors.
- Liu, Tao,Qiao, Jennifer X.,Poss, Michael A.,Yu, Jin-Quan
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supporting information
p. 10924 - 10927
(2017/08/30)
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- Synthesis of Organophosphorus Compounds through Copper-Catalyzed Annulation Involving C-O and C-P Bond Formations
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A novel copper(II) trifluoromethanesulfonate-catalyzed, high-efficiency, and atom-economical synthesis of valuable organophosphorus compounds via cascade annulation of propargylic alcohols with diphenylphosphine oxide is described. This protocol, which has a good functional-group compatibility and insensitivity to an ambient atmosphere, provides a simple and direct pathway to the products, organophosphorus compounds, in good yields under mild conditions. The method could be efficiently scaled up to gram scale, thus highlighting a potential application of this methodology.
- Li, Xue-Song,Han, Ya-Ping,Zhu, Xin-Yu,Li, Ming,Wei, Wan-Xu,Liang, Yong-Min
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p. 11636 - 11643
(2017/11/10)
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- Triazole Ureas Act as Diacylglycerol Lipase Inhibitors and Prevent Fasting-Induced Refeeding
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Triazole ureas constitute a versatile class of irreversible inhibitors that target serine hydrolases in both cells and animal models. We have previously reported that triazole ureas can act as selective and CNS-active inhibitors for diacylglycerol lipases (DAGLs), enzymes responsible for the biosynthesis of 2-arachidonoylglycerol (2-AG) that activates cannabinoid CB1 receptor. Here, we report the enantio- and diastereoselective synthesis and structure-activity relationship studies. We found that 2,4-substituted triazole ureas with a biphenylmethanol group provided the most optimal scaffold. Introduction of a chiral ether substituent on the 5-position of the piperidine ring provided ultrapotent inhibitor 38 (DH376) with picomolar activity. Compound 38 temporarily reduces fasting-induced refeeding of mice, thereby emulating the effect of cannabinoid CB1-receptor inverse agonists. This was mirrored by 39 (DO34) but also by the negative control compound 40 (DO53) (which does not inhibit DAGL), which indicates the triazole ureas may affect the energy balance in mice through multiple molecular targets.
- Deng, Hui,Kooijman, Sander,Van Den Nieuwendijk, Adrianus M. C. H.,Ogasawara, Daisuke,Van der Wel, Tom,Van Dalen, Floris,Baggelaar, Marc P.,Janssen, Freek J.,Van Den Berg, Richard J. B. H. N.,Den Dulk, Hans,Cravatt, Benjamin F.,Overkleeft, Herman S.,Rensen, Patrick C. N.,Van der Stelt, Mario
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supporting information
p. 428 - 440
(2017/04/26)
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- BF3·OEt2-AgSCF3 Mediated Trifluoromethylthiolation/Cascade Cyclization of Propynols: Synthesis of 4-((Trifluoromethyl)thio)-2H-chromene and 4-((Trifluoromethyl)thio)-1,2-dihydroquinoline Derivatives
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A BF3·OEt2-AgSCF3 mediated direct trifluoromethylthiolation/cascade cyclization of propynols involving the SCF3 anion nucleophilic pathway is developed. This protocol also provides an opportunity to construct valuable trifluoromethylthio-substituted 2H-chromene and 1,2-dihydroquinoline systems with high efficiency under mild conditions. Additionally, the developed BF3·OEt2-AgSCF3 reaction system could be scaled up to gram quantities in a satisfactory yield without inert gas protection.
- Qiu, Yi-Feng,Song, Xian-Rong,Li, Ming,Zhu, Xin-Yu,Wang, An-Qi,Yang, Fang,Han, Ya-Ping,Zhang, Heng-Rui,Jin, Dong-Po,Li, Ying-Xiu,Liang, Yong-Min
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supporting information
p. 1514 - 1517
(2016/05/02)
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- Complementary iron(II)-catalyzed oxidative transformations of allenes with different oxidants
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Substituent- and oxidant-dependent transformations of allenes are described. Given the profound influence of the substituent on the reactivity of allenes, the subtle differences in allene structures are manifested in the formation of diverse products when reacted with different electrophiles/oxidants. In general, reactions of nonsilylated allenes involve an allylic cation intermediate by forming a C-O bond, at the sp-hybridized C2, with either DDQ (2,3-dichloro-5,6-dicyano-p-benzoquinone) or TBHP (tert-butyl hydroperoxide), along with FeCl2·4 H2O (10 mol %). In contrast, silylated allenes favor the formation of propargylic cation intermediates by transferring the allenic hydride to the oxidant, thus generating 1,3-enynes (E1 product) or propargylic THBP ethers (SN1 product). The formation of these different putative cationic intermediates from nonsilylated and silylated allenes is strongly supported by DFT calculations. Profound impact: Iron(II)-catalyzed transformations of allenes induced by either DDQ or tBuOOH depend on the substituent on the allenes. Nonsilylated and silylated allenes show complementary reactivity upon exposure to DDQ and tBuOOH in the presence of an iron(II) catalyst. Nonsilylated allenes incorporate the oxidant at the sp-hybridized carbon, whereas the silylated allenes generate 1,4-dehydrogenated 1,3-enynes. DDQ=2,3-dichloro-5,6-dicyano-1,4-benzoquinone.
- Sabbasani, Venkata R.,Lee, Hyunjin,Xia, Yuanzhi,Lee, Daesung
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supporting information
p. 1151 - 1155
(2016/01/20)
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- DDQ-Mediated Oxidative Radical Cycloisomerization of 1,5-Diynols: Regioselective Synthesis of Benzo[b]fluorenones under Metal-Free Conditions
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A regio- and chemoselective oxidative cycloisomerization reaction of acyclic 1,5-diynols has been developed. The reaction proceeds under metal-free reaction conditions with high efficiency and broad functional group tolerance, which offers a general and straightforward access to benzo[b]fluorenones under metal-free conditions. The preliminary mechanistic studies revealed the possible involvement of a Meyer-Schuster rearrangement combined with an oxidative radical cyclization.
- Zhu, Hui,Chen, Zhiyuan
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supporting information
p. 488 - 491
(2016/02/18)
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- Boronic acid/Br?nsted acid co-catalyst systems for the synthesis of 2: H -chromenes from phenols and α,β-unsaturated carbonyls
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Protocols for the synthesis of substituted 2H-chromenes from α,β-unsaturated carbonyls and phenols are described. Optimal combinations of arylboronic acids and Br?nsted acids have been identified, such that both can be employed in catalytic quantities to accelerate these condensations. The method has been used to synthesize a variety of substituted 2H-chromenes, as well as photochromic naphthopyrans. The use of pentafluorophenylboronic acid and diphenylphosphinic acid enabled an expansion of the electrophile scope to include α,β-unsaturated ketones. Hall's 'phase-switching' of boronic acids has been exploited to achieve the separation of the two co-catalysts from unpurified reaction mixtures by a simple liquid-liquid extraction.
- Dimakos, Victoria,Singh, Tishaan,Taylor, Mark S.
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p. 6703 - 6711
(2016/07/21)
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- Efficient synthesis and antibacterial activities of some novel 1,2,3-triazoles prepared from propargylic alcohols and benzyl azides
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A simple and effective procedure for regioselective preparation of 1,2,3-triazoles from benzyl azides and propargylic alcohols is described using CuSO4·5H2O and sodium ascorbate. To screen the antibacterial activity of some newly synthesized triazole derivatives, minimum inhibitory concentration of 3d and 3k was evaluated against gram positive Staphylococcus aureus and Bacillus subtilis and gram negative Escherichia coli and Pseudomonas aeruginosa.
- Hosseinzadeh, Rahman,Abolfazli, Mohammadreza Khadem,Mohseni, Mojtaba,Mohadjerani, Maryam,Lasemi, Zahra
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p. 1298 - 1305
(2015/04/27)
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- Lewis acid catalyzed cascade reaction of 3-(2-benzenesulfonamide)propargylic alcohols to spiro[indene-benzosultam]s
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A highly efficient and convenient construction of the spiro[indene-benzosultam] skeleton from propargylic alcohols has been developed. The reaction proceeded in a Lewis acid catalyzed cascade process, including the trapping of allene carbocation with sulfonamide, electrophilic cyclization, and intramolecular Friedel-Crafts alkylation. In the presence of NIS or NBS, iodo/bromo-substituted spiro[indene-benzosultam]s could be prepared in excellent yields.
- Sun, Lang,Zhu, Yuanxun,Wang, Jing,Lu, Ping,Wang, Yanguang
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supporting information
p. 242 - 245
(2015/02/19)
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- Convenient and highly efficient routes to 2 H-chromene and 4-chromanone derivatives: Iodine-promoted and p-toluenesulfonic acid catalyzed cascade cyclizations of propynols
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A convenient strategy is presented for the easy preparation of a series of 2 H-chromenes under mild conditions through iodocyclization of readily accessible propynols. In addition, various 4-chromanones can be synthesized through a p-toluenesulfonic acid catalyzed cascade cyclization with high efficiency (yields up to 99%). Our developed reaction systems are proven to have good functional-group applicability and can be scaled up to gram quantities in satisfactory yields. These systems also provide a new synthetic strategy for two types of important flavonoid skeleton without using costly and toxic metal catalysts. Additionally, the resulting halides could be further exploited in subsequent palladium-catalyzed coupling reactions, so these compounds could act as potential intermediates for the construction of some valuable drug molecules.
- Qiu, Yi-Feng,Ye, Yu-Ying,Song, Xian-Rong,Zhu, Xin-Yu,Yang, Fang,Song, Bo,Wang, Jia,Hua, Hui-Liang,He, Yu-Tao,Han, Ya-Ping,Liu, Xue-Yuan,Liang, Yong-Min
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supporting information
p. 3480 - 3487
(2015/03/04)
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- Fluoride-assisted activation of calcium carbide: A simple method for the ethynylation of aldehydes and ketones
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The fluoride-assisted ethynylation of ketones and aldehydes is described using commercially available calcium carbide with typically 5 mol % of TBAF·3H2O as the catalyst in DMSO. Activation of calcium carbide by fluoride is thought to generate an acetylide "ate"-complex that readily adds to carbonyl groups. Aliphatic aldehydes and ketones generally provide high yields, whereas aromatic carbonyls afford propargylic alcohols with moderate to good yields. The use of calcium carbide as a safe acetylide ion source along with economic amounts of TBAF·3H2O make this procedure a cheap and operationally simple method for the preparation of propargylic alcohols.
- Hosseini, Abolfazl,Seidel, Daniel,Miska, Andreas,Schreiner, Peter R.
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supporting information
p. 2808 - 2811
(2015/06/16)
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- Convenient synthesis of naphthopyrans using montmorillonite K-10 as heterogeneous catalyst
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A simple and mild procedure for the synthesis of different naphthopyrans providing high yields in a short reaction time was reported. The reaction of propargylic alcohols with α- or β-naphthol and dihydroxy naphthalenes in the presence of montmorillonite K-10 was studied. This reaction afforded high yields of the corresponding naphthopyrans. In addition, a number of new phenylene and biphenylen-linked bisnaphthopyrans were synthesized providing excellent yields via the one-pot reaction of bis-propargyl alcohols with β-naphthol.
- Hosseinzadeh, Rahman,Mohadjerani, Maryam,Javad Ardestanian, Mohammad,Naimi-Jamal, Mohammad Reza,Lasemi, Zahra
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p. 1081 - 1089
(2014/11/08)
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- Facile synthesis of halogenated spiroketals via a tandem iodocyclization
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A strategy for the synthesis of spiroketal compounds through a tandem iodocyclization of 1-(2-ethynylphenyl)-4-hydroxybut-2-yn-1-one derivatives is presented. This reaction could proceed under very mild conditions in a short time and avoid the use of expensive and toxic metal catalysts. Moreover, the resulting halides can be further exploited by subsequent palladium-catalyzed coupling reactions, which act as the important intermediates for building other valuable compounds.
- Wang, Jia,Zhu, Hai-Tao,Li, Ying-Xiu,Wang, Li-Jing,Qiu, Yi-Feng,Qiu, Zi-Hang,Zhong, Mei-Jin,Liu, Xue-Yuan,Liang, Yong-Min
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supporting information
p. 2236 - 2239
(2014/05/06)
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- Bronsted acid mediated nitrogenation of propargylic alcohols: An efficient approach to alkenyl nitriles
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A novel and efficient approach to alkenyl nitriles from readily available propargylic alcohols has been developed. This nitrogenation reaction is transition-metal-free and could be conducted under air at ambient temperature, which makes this protocol promising and practical. Moreover, NH4Br is disclosed as an efficient additive to promote the stereoselectivity of this reaction. the Partner Organisations 2014.
- Huang, Xiaoqiang,Jiao, Ning
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supporting information
p. 4324 - 4328
(2014/06/23)
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- Design of pH responsive clickable prodrugs applied to histone deacetylase inhibitors: A new strategy for anticancer therapy
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The aim of this study was to develop clickable prodrugs bearing a tunable pH responsive linker designed for acidic pH-mediated release of histone deacetylase inhibitors. HDACi are an important class of molecules belonging to the epigenetic modulators used for innovative cancer strategies. The behavior of these prodrugs was determined by a bioluminescence resonance energy transfer assay in living tumor cells. This work demonstrated that this innovative type of clickable prodrugs entered cancer cells and showed restored anti proliferative properties attributed to the effective release of the HDAC inhibitors. A correlation between kinetic studies, dose responses, and biological activities was obtained, making such clickable prodrugs good candidates for new strategies in epigenetic-oriented anticancer therapies.
- Delatouche, Régis,Denis, Iza,Grinda, Marion,Bahhaj, Fatima El,Baucher, Estelle,Collette, Floraine,Héroguez, Valérie,Grégoire, Marc,Blanquart, Christophe,Bertrand, Philippe
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p. 862 - 872
(2014/01/06)
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- Regioselective rapid synthesis of fully substituted 1,2,3-triazoles mediated by propargyl cations
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Regioselective rapid triazole syntheses at low temperature are described. Organic azides and propargyl cations generated by acids gave fully substituted 1H-1,2,3-triazoles. Most reactions could be performed in 5 min at not only rt but also -90 C. Both terminal and internal alkynes were acceptable, and the sterically bulky substituents could afford the products smoothly. Various types of three-component coupling reactions were demonstrated, and the presence of allenylaminodiazonium intermediates was indicated.
- Zhang, Huan,Tanimoto, Hiroki,Morimoto, Tsumoru,Nishiyama, Yasuhiro,Kakiuchi, Kiyomi
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supporting information
p. 5222 - 5225
(2013/11/06)
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- Synthesis of allenes via gold-catalyzed intermolecular reaction of propargylic alcohols and aromatic compounds
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Functionalized allenes are efficiently synthesized in moderate to high yield from gold-catalyzed intermolecular reaction of propargylic alcohols and aromatic compounds. The user-friendly process could be conducted under mild reaction conditions with easily accessible starting materials.
- Xu, Cheng-Fu,Xu, Mei,Yang, Liu-Qing,Li, Chuan-Ying
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experimental part
p. 3010 - 3016
(2012/05/05)
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- The synthesis and properties of vinyl substituted naphthopyrans and their styrene copolymers
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A comprehensive series of mono-, di- and tri-bromo-3H-naphtho[2,1-b]pyrans was synthesised by the traditional union of a 2-naphthol with an alkynol. The bromine atom(s) in these naphthopyrans was readily replaced by a vinyl group using a Suzuki coupling reaction with vinyl boronic anhydride pyridine complex. The efficiency of the Suzuki vinylation reaction decreases with the increasing number of bromine atoms to be substituted. The vinylnaphthopyrans served as styrene analogues and readily underwent a thermally initiated free radical addition co-polymerisation with styrene to efficiently afford low molecular weight poly(styrene-co-naphthopyrans). The photochromic response of the bromonaphthopyrans and vinylnaphthopyrans followed the established colour-structure relationships for photochromic naphthopyrans. The photochromic response of toluene solutions of the poly(styrene-co-naphthopyrans) was characterised by a hypsochromic shift of the λmax relative to that recorded for the vinylnaphthopyran monomers. Increased half-lives were noted for the copolymers derived from the bis- and tris-vinylnaphthopyrans where some degree of crosslinking was expected. A further hypsochromic shift in λmax resulted for the thin films of the poly(styrene-co- naphthopyrans). Of particular note was the behaviour of the 3-(2-vinylphenyl)-3- phenylnaphthopyran which gave the typical yellow colour of the photomerocyanine coupled with the predictable large half-life. However, all photochromism of this naphthopyran was lost upon polymerisation suggesting that an alternative pathway supervenes in the expected polymerisation sequence.
- Blackwell, Catherine J.,Gabbutt, Christopher D.,Guthrie, James T.,Heron, B. Mark
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experimental part
p. 408 - 420
(2012/08/28)
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- Bronsted acid-catalyzed cycloisomerization of but-2-yne-1,4-diols with or without 1,3-dicarbonyl compounds to tri- and tetrasubstituted furans
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A Bronsted acid-catalyzed method to prepare tri- and tetrasubstituted furans efficiently from cycloisomerization of but-2-yne-1,4-diols with or without 1,3-dicarbonyl compounds is described. By taking advantage of the orthogonal modes of reactivity of the alcoholic substrate through slight modification of the reaction conditions, a divergence in product selectivity was observed. At room temperature, p-TsOH?H 2O-mediated tandem alkylation/cycloisomerization of the propargylic 1,4-diol with the β-dicarbonyl compound was found to selectively occur to provide the tetrasubstituted furan product. On the other hand, increasing the reaction temperature to 80 °C was discovered to result in preferential p-TsOH?H2O-catalyzed dehydrative rearrangement of the unsaturated alcohol and formation of the 2,3,5-trisubstituted furan adduct.
- Mothe, Srinivasa Reddy,Lauw, Sherman Jun Liang,Kothandaraman, Prasath,Chan, Philip Wai Hong
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experimental part
p. 6937 - 6947
(2012/10/07)
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- Tandem reaction of propargyl alcohol and N-sulfonylhydrazone: Synthesis of dihydropyrazole and its utility in the preparation of 3,3-diarylacrylonitrile
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An efficient and straightforward strategy for the synthesis of 4-methylene-1-(phenylsulfonyl)-4,5-dihydro-1H-pyrazole from propargyl alcohol and N-sulfonylhydrazone is described. N-Sulfonyl allenamide is postulated to be the key intermediate for this tandem transformation.
- Zhu, Yuanxun,Wen, Shan,Yin, Guangwei,Hong, Deng,Lu, Ping,Wang, Yanguang
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supporting information; experimental part
p. 3553 - 3555
(2011/09/14)
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- Efficient synthesis of di- and trisubstituted 2-aryloxazoles via ytterbium(III) triflate catalyzed cyclization of tertiary propargylic alcohols with aryl amides
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An efficient synthetic method to prepare di- and trisubstituted 2-aryloxazoles based on Yb(OTf)3 catalyzed cyclization of trisubstituted propargylic alcohols with aryl amides is described. The reaction was accomplished in moderate to excellent product yields and with complete regioselective control. The mechanism is suggested to involve activation of the starting alcohol by the metal catalyst that results in its ionization. Subsequent cyclization of this newly generated carbocationic species with the aryl amide then affords the oxazole. In view of the mild conditions along with the low cost, commercially availability of Yb(OTf)3 and its high tolerance to air and moisture, the present synthetic approach offers an operationally simplistic and convenient route to this important aromatic heterocycle.
- Zhang, Xiaoxiang,Teo, Wan Teng,Chan, Philip Wai Hong
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supporting information; experimental part
p. 331 - 337
(2011/02/17)
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- Synthesis and photochromic properties of substituted naphthopyran compounds
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A group of 3,3-diaryl-3H-naphtho[2,1-b]pyran compounds with functional substituents at the 5- and 6-positions of the naphthopyran skeleton and the para positions at the 3-aryl moieties were prepared through condensation reactions between 2-naphthol derivatives and 1,1-diarylprop-2-yn-1-ol derivatives. The chemical structures of the compounds were confirmed by NMR and MS. The crystal structure of 3,3-diphenyl-6-morpholino-3H-naphtho[2,1-b]pyran (4b) was determined and the relationship between the pyran substructure and photochromism was discussed. The photochromic properties were studied as well, and decoloration kinetics of colored forms was fitted to the biexponential model. Among these compounds, 4b was considered to be the best one due to the large ΔOD of colored form, which is one of the most important properties used in the photochromic material.
- Wang, Zhen,Meng, Qinghua,Zhang, Zhihui,Fu, Dingliang,Zhang, Wanbin
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experimental part
p. 2246 - 2250
(2011/04/22)
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- Novel triazolyl derivatives for acidic release of amines
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Triazolyl derivatives of amines were prepared using click chemistry and evaluated as releasing systems in mildly acidic environments. Triazolylcarbamates and alkylamines were obtained, depending on the reactivity of the propargylic intermediates used for the Huisgen cycloaddition. A fast hydrolysis of some derivatives in mildly acidic conditions was achieved. The relative rates were correlated to a proposed mechanism highlighting the complementary role of the triazole ring and carbocation reactivity/stability. Copyright
- Delatouche, Regis,Mondon, Martine,Gil, Adri,Frapper, Gilles,Bachmann, Christian,Bertrand, Philippe
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supporting information; experimental part
p. 401 - 407
(2011/03/18)
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- Triazolyl derivatives for acidic release of alcohols
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New triazolyl-based carbonates and ethers have been investigated as potential alcohol-releasing systems under mild acidic conditions. Triazolyl carbonates could not be prepared because of their apparent instability, whereas ethers were successfully obtained. The rate of hydrolysis of these ethers ramged from a few hours to several days. A theoretical investigation demonstrated that the acidic release of alcohols from triazole derivatives proceeds first by protonation of the triazole ring followed by proton transfer from the triazole ring to the carbonyl group of the carbonates or to the oxygen atom of the ether derivatives. The rate of the decomposition reaction was shown to depend on the length of the N3-H···O hydrogen bond in the intermediate C-NH+/E-NH+ structures and on the stability of the triazole carbocation, which is closely related to the π-donating effect of its R2 and R3 substituents. Copyright
- Mondon, Martine,Delatouche, Regis,Bachmann, Christian,Frapper, Gilles,Len, Christophe,Bertrand, Philippe
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supporting information; experimental part
p. 2111 - 2119
(2011/05/16)
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- Bronsted acid catalyzed cyclization of propargylic alcohols with thioamides. Facile synthesis of Di- and trisubstituted thiazoles
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Figure presented. A general and efficient method to prepare 2,4-di- and trisubstituted thiazoles via p-TsOH·H2O-catalyzed cyclization of trisubstituted propargylic alcohols with thioamides is described. The reaction was accomplished in moderate to excellent product yields under mild conditions that did not require the exclusion of air and moisture and offers an operationally simplistic and convenient route to this synthetically useful aromatic heterocycle.
- Zhang, Xiaoxiang,Teo, Wan Teng,Sally,Chan, Philip Wai Hong
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supporting information; experimental part
p. 6290 - 6293
(2010/11/18)
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- Ytterbium(III) triflate catalyzed tandem friedel-crafts alkylation/hydroarylation of propargylic alcohols with phenols as an expedient route to indenols
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A method to prepare indenols efficiently by ytterbium(III) triflate catalyzed tandem Friedel - Crafts alkylation/hydroarylation of propargylic alcohols with phenols is described. The reaction was accomplished In moderate to excellent yields and regioselectivity under mild conditions and offers a straightforward and convenient one step synthetic route to bioactive indenols and its derivatives.
- Zhang, Xiaoxiang,Teo, Wan Teng,Chan, Philip Wai Hong
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supporting information; experimental part
p. 4990 - 4993
(2009/12/28)
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- The intricate assembling of gem-diphenylpropargylic units
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While optimized procedures for selective propargylic - versus allenic - attack (in particular by alkynylsilanes) have proven to be compatible with many substitution patterns at the propargylic center, the case of diarylpropargyl electrophiles has remained problematic. The intrinsic reactivity of 1,1-diphenylpropargylic alcohols [R-C≡C-C(Ph2)OH (R = TMS, H, Me)] in the presence of various acids (and in the absence of additional nucleophile) has thus been systematically investigated. Whereas the monophenyl analogues [R-C≡C-CH(Ph)OH] afford the expected bis(phenylpropargyl) ethers, the diphenyl versions undergo complex but quite selective processes to afford various structural types: depending on the acid used, a diallene, an allenyne, an indenylallene, an indanone or a condensed tetra- and pentacycles were obtained. When the reactions were conducted in the presence of an alkynylsilane capable of playing the role of a competing nucleophile, the expected propargylic substitution products - dialkynyldiphenylmethanes or their isomers - were never observed. The hitherto unknown simple hydrocarbons diethynyl- and dipropynyl-diphenylmethane could, however, be obtained in low yields through a four-step sequence involving allenylidene- and alkynylruthenium intermediates. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Maraval, Valerie,Duhayon, Carine,Coppel, Yannick,Chauvin, Remi
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experimental part
p. 5144 - 5156
(2009/08/07)
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- Rhodium-catalyzed hydroalkynylation of internal alkynes with silylacetylenes: An alkynylrhodium(I) intermediate generated from the hydroxorhodium(I) complex [Rh(OH)(binap)]2
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A highly selective hydroalkynylation of internal alkynes with silylacetylenes giving 1,3-enynes was realized by use of a hydroxorhodium catalyst. As a key intermediate in the catalytic cycle, an alkynylrhodium(I) complex was isolated and investigated for its structure and reactivity.
- Nishimura, Takahiro,Guo, Xun-Xiang,Ohnishi, Kohei,Hayashi, Tamio
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p. 2669 - 2672
(2008/09/19)
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- MUSCARINIC RECEPTOR ANTAGONISTS
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This present invention generally relates to muscarinic receptor antagonists, which are useful, among other uses, for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems mediated through muscarinic receptors. The invention also relates to the process for the prepration of disclosed compounds, pharmaceutical compositions containing the disclosed compounds, and the methods for treating diseases mediated through muscarinic receptors.
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Page/Page column 31
(2008/06/13)
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- Nickel-catalyzed dimerization of [5]cumulenes (Hexapentaenes)
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Tetraaryl[5]cumulenes react with low-valent nickel complexes at the second double bond to produce novel [4]radialene derivatives that are head-to-head dimers of [5]cumulenes. The head-to-head dimers are also synthesized by a stepwise route. On the other hand, the nickel-catalyzed dimerization of [5]cumulenes with bulky substituents produces other types of extended [4]radialenes and [5]radialenones depending on the bulkiness of the terminal alkyl substituents. Thus, tetrakis-t-butyl[5]cumulene and 1,4-bis(2,2,6,6- tetramethylcyclohexylidene)[3]cumulene react at the central double bond to give the corresponding [4]radialene and [5]radialenone, whereas 1,4-bis(2,2,5,5- tetramethylcyclopentylidene)[3]cumulene and its benzo-annelated derivative react at the second double bond in a head-to-tail manner to afford the corresponding extended [4]radialenes. Tetrakis-t-butyl[5]radialenone was converted into [5]radialene by using a methylation-dehydration procedure. The extended [4]- and [5]radialenes and [5]radialenones have been fully characterized by spectroscopic analyses, X-ray crystallography, and/or independent chemical synthesis. The properties of these novel exocyclic π-electron systems have been investigated in detail. The aryl-substituted [4]radialenes exhibit facile bond rotation with low energy barriers. The [5]radialene and [5]radialenone form the corresponding cations easily by the addition of an acidic proton. The selectivity of the nickel-catalyzed dimerization of [5]cumulenes is discussed on the basis of theoretical calculations.
- Kuwatani, Yoshiyuki,Yamamoto, Gaku,Oda, Masaji,Iyoda, Masahiko
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p. 2188 - 2208
(2007/10/03)
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- Synthesis and NMR spectroscopic characterization of some fluoro-2H-1-benzopyran derivatives
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The synthesis of some new fluoro-2H-1-benzopyran derivatives utilizing a reaction between titanium phenolates and β-phenylcinnamaldehydes in toluene is reported. These compounds were characterized by NMR and UV/visible spectroscopy as well as mass spectrometry. In solution all the compounds are photochromic. Complete assignment of the 1H and 13C resonances was achieved by concerted application of homonuclear (gs-COSY), proton-detected (C, H) one-bond (gs-HMQC), and long-range (gs-HMBC) heteronuclear two-dimensional chemical shift correlation experiments using a 500 MHz NMR spectrometer equipped with a cryoplatform and a 5 mm cryoprobe. The mass spectra of the different compounds were characterized by intense molecular and high fragment ions. The introduction of an atom of fluorine as a molecular probe is of interest in determining the mechanistic aspects of the photochemical process. CSIRO 2005.
- Teral, Yannick,Roubaud, Gabriel,Aubert, Claude,Faure, Robert,Campredon, Mylene
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p. 517 - 521
(2007/10/03)
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- PYRANO-QUINOLINES, PYRANO-QUINOLINONES, COMBINATIONS THEREOF, PHOTOCHROMIC COMPOSITIONS AND ARTICLES
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Described are compositions of at least one material represented by a pyrano[3,2-c]quinoline structure, a pyrano[3,2-c]quinolinone structure or mixtures thereof. The pyrano[3,2-c]quinoline structure is characterized by having a nitrogen atom at the 6-position ring atom and an oxy-substituent at the 5-position ring atom. The pyrano[3,2-c]quinolinone structure is characterized by having a substituted nitrogen atom at the 6-position ring atom and an oxo-substituent at the 5-position ring atom, the nitrogen atom substituents being hydrogen, aliphatic substituents, cycloaliphatic substituents, aromatic substituents, heteroaromatic substituents or a combination thereof. Both of the pyrano[3,2-c]quinoline and pyrano[3,2-c]quinolinone structures are characterized by having two substituents at the 2-position ring atom, each substituent being independently chosen from aliphatic substituents, cycloaliphatic substituents, aromatic substituents, heteroaromatic substituents or a combination thereof, provided that both substituents at the 2-position are not aliphatic. Alternatively, the two substituents at the 2-position can combine to form a spirocyclic group, provided that the spirocyclic group is not norbornylidene or bicyclo[3.3.1]9-nonylidene. The ring atoms have been numbered according to the International Union of Pure and Applied Chemistry rules of nomenclature starting with the 1-position ring atom being the oxygen atom of the pyran ring and numbering counterclockwise therefrom. Also described are photochromic articles that contain or that have coatings or films containing at least one of the novel compositions or combinations thereof with other photochromic materials.
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Page/Page column 40
(2010/02/12)
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- Photochromic heterocyclically anellated indenochromene compounds
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The present invention relates to specific photochromic heterocyclically annellated indenochromene derivatives and the use thereof in plastics of all types, particularly for ophthalmic applications. In particular, the present invention relates to indeno[2,1-f]chromene derivatives having the following general formula (I) and indeno[1,2-h]chromene derivatives having the following general formula (II):
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Page column 14
(2010/02/06)
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- Photochromic naphthopyran compounds
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A naphthopyran compound represented by the formula: wherein R4, R5, R6, R7, R8, R9, R10, and R11are each selected from the group consisting essentially of hydrogen, a first stable organic radical, a heterocyclic group, halogen, a first nitrogen-substituted group, and a first nitrogen-substituted ring compound; A and B are each selected from the group consisting essentially of hydrogen, substituted phenyl, and substituted naphthyl, provided that at least one of A or B is substituted phenyl or substituted naphthyl; and any substituent of any substituted phenyl or substituted naphthyl at A or B is selected from the group consisting essentially of hydrogen, a second stable organic radical, a heterocyclic group, halogen, a second nitrogen-substituted group, and a second nitrogen-substituted ring compound, provided that at least one substituent of any substituted phenyl or substituted naphthyl at either A or B is phenyl, naphthyl, or furyl.
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- Photochromic behaviour of Bis[4-(N,N-dimethylamino)phenyl]-substituted 3H-naphtho[2,1-b]pyran and 2H-1-Benzopyran
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The photochromic behaviour of 3,3-bis[4-(N,N-dimethylamino)phenyl]-3H-naphtho[2,1 -b]pyran (2) and 2,2-bis[4-(N,N-dimethylamino)phenyl]-2H-1 -benzopyran (3) has been studied by flash photolysis and compared to 3,3-diphenyl-3H-naphtho[2,1 -b]pyran (i) in order to delineate effects due to the N,N-dimethylamino groups.
- Harie, Guenaelle,Samat, Andre,Guglielmetti, Robert,De Keukeleire, Denis,Saeyens, Wim,Van Parys, Inge
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p. 3075 - 3078
(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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