19823-75-7Relevant academic research and scientific papers
Antimicrobial Hydantoin-grafted Poly(ε-caprolactone) by Ring-opening Polymerization and Click Chemistry
Tan, Licheng,Maji, Samarendra,Mattheis, Claudia,Chen, Yiwang,Agarwal, Seema
, p. 1721 - 1730 (2012)
Novel degradable and antibacterial polycaprolactone-based polymers are reported in this work. The polyesters with pendent propargyl groups are successfully prepared by ring-opening polymerization and subsequently used to graft antibacterial hydantoin moieties via click chemistry by a copper(I)-catalyzed azide-alkyne cycloaddition reaction. The well-controlled chemical structures of the grafted copolymers and its precursors are verified by FT-IR spectroscopy, NMR spectroscopy, and GPC characterizations. According to the DSC and XRD results, the polymorphisms of these grafted copolymers are mostly changed from semicrystalline to amorphous depending on the amount of grafted hydantoin. Antibacterial assays are carried out with Bacillus subtilis and two strains of Escherichia coli and show fast antibacterial action.
Formation and characterization of inclusion complexes of alkyne functionalized poly(ε-caprolactone) with β-cyclodextrin. Pseudo-polyrotaxane-based supramolecular organogels
Jazkewitsch, Olga,Ritter, Helmut
, p. 375 - 382 (2011)
β-Cyclodextrin has been found to form pseudo-polyrotaxanes with propargyl functionalized poly(ε-caprolactone) in N,N-dimethylformamide. The formation of inclusion complexes was proven by 1H NMR and FT-IR spectroscopy, SEC, dynamic light scatter
Cyclodextrin-modified polyesters from lactones and from bacteria: An approach to new drug carrier systems
Jazkewitsch, Olga,Mondrzyk, Adam,Staffel, Rebecca,Ritter, Helmut
, p. 1365 - 1371 (2011)
Copper(I)-catalyzed cycloaddition of synthetic and bacterial copolyesters bearing pendant alkyne group with mono-(6-azido-6-desoxy)-β-cyclodextrin was carried out to synthesize β-CD-functionalized copolyester. The synthetic clickable copolyesters were obtained by the ring-opening copolymerization of the propargyl-modified lactones and ε-caprolactone. The bacterial copolyesters containing an alkyne group were biosynthesized from a mixture of 10-undecynoic acid and hexanoic acid by the Gram-negative bacteria Pseudomonas oleovorans. The modified products of the click reaction were characterized by FT-IR, 1H NMR spectroscopy, and DSC. Furthermore, the host guest capability of covalently attached β-cyclodextrin moieties was proved by dynamic light scattering measurements.
Regioselective Crossed Aldol Reactions under Mild Conditions via Synergistic Gold-Iron Catalysis
Chen, Hao,Jean, Jonathan,Shan, Chuan,Shi, Xiaodong,Teng, Shun,Wang, Jin,Wojtas, Lukasz,Ye, Xiaohan,Yi, Yaping,Yuan, Teng,Zhao, Pengyi
, p. 1420 - 1431 (2020/06/19)
A synergistic gold-iron (Au-Fe) catalytic system was developed for sequential alkyne hydration and vinyl Au addition to aldehydes or ketones. Fe(acac)3 was identified as an essential co-catalyst in preventing vinyl Au protodeauration and facilitating nucleophilic additions. Effective C–C bond formation was achieved under mild conditions (room temperature) with excellent regioselectivity and high efficiency (1% [Au], up to 95% yields). The intramolecular reaction was also achieved, giving successful macrocyclization (16–31 ring sizes) with excellent yields (up to 90%, gram scale) without extended dilution (0.2 M), which highlights the great potential of this new crossed aldol strategy in challenging target molecule synthesis. Effective construction of the C–C bond is one of the most important tasks in organic synthesis. Whereas aldol condensation is a classic C–C bond-forming transformation, it requires other chemical promoters, such as strong base and reactive acidic catalysts. As a result, the overall transformation is limited in terms of ideal atom economy and environmentally friendly operation. With the discovery of a gold-iron (Au-Fe) synergistic catalysis system, here we describe a new approach to facilitating alkyne hydration and sequential vinyl Au addition to carbonyls. This approach gives the C–C bond-forming products in excellent yields, wide substrate scope, and great functional-group compatibility under mild conditions. This protocol can also be applied to macrocyclization without extended dilution. This C–C bond-forming strategy could facilitate challenging molecule synthesis in chemical, biological, and medicinal research. We report a synergistic gold-iron (Au-Fe) catalytic system to access vinyl Au reactivity by avoiding frequently occurring protodeauration. Fe(acac)3 was identified as an essential co-catalyst, facilitating vinyl Au addition to aldehydes. A broad substrate scope was obtained under mild conditions (room temperature) with excellent regioselectivity and high efficiency (1% [Au], up to 95% yields). This protocol offers a practical solution for achieving macrocyclization (16–31 ring sizes, up to 90%, gram scale) without extended dilution, highlighting the synthetic utility in complex molecular synthesis.
Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis
Cao, Zhen,Lacoudre, Aline,Rossy, Cybille,Bibal, Brigitte
supporting information, p. 2465 - 2472 (2019/11/11)
The bis-ortho-thioether 9,10-bis[(o-methylthio)phenyl]anthracene was synthesized as a syn-atropisomer, as revealed by X-ray diffraction. This alkylaryl thioether ligand (L) formed different macrocyclic complexes by coordination with silver(I) salts depending on the nature of the anion: M2L2 for AgOTf and AgOTFA, M6L4 for AgNO3. A discrete M2L complex was obtained in the presence of bulky PPh3AgOTf. These silver(I) complexes adopted similar structures in solution and in the solid state. As each sulfur atom in the ligand is prochiral, macrocycles L2M2 were obtained as mixtures of diastereoisomers, depending on the configurations of the sulfur atoms coordinated to silver cations. The X-ray structures of the two L2·(AgOTf)2 stereoisomers highlighted their different geometry. The catalytic activity of all silver(I) complexes was effective under homogeneous conditions in two tandem addition/cycloisomerization of alkynes using 0.5-1 mol % of catalytic loading.
Bismuth(iii)-catalyzed cycloisomerization and (hetero)arylation of alkynols: Simple access to 2-(hetero)aryl tetrahydrofurans and tetrahydropyrans
Nakate, Ashwini K.,Pratapure, Madhukar S.,Kontham, Ravindar
supporting information, p. 3229 - 3240 (2018/05/15)
2-(Hetero)aryl tetrahydrofurans and tetrahydropyrans were successfully synthesized using Bi(OTf)3-catalyzed hydroalkoxylation (cycloisomerization) of alkynols (via 5 or 6 exo-dig cyclization) and intermolecular (hetero)arylation. This reaction involves a highly efficient cascade process, where initially the alkynol undergoes a cycloisomerization step via activation of the triple bond and generates the oxocarbenium ion, which subsequently participates in the (hetero)hydroarylation step with electron-rich arenes. Simple to complex suitably functionalized alkynols (4-pentyn-1-ols and 5-hexyn-1-ols) and electron-rich aromatic compounds were found to be reliable substrates in this cascade transformation and furnished a wide range of oxygen heterocycles. This practical tandem process provides a means to build libraries related to pharmacologically active molecules and natural product like scaffolds.
Chemoenzymatic route to optically active dihydroxy cyclopenta[b]naphthalenones; precursors for decalin-based bioactive natural products
?zdemirhan, Devrim,Sar??elik, ?zlem
, p. 118 - 124 (2017/01/12)
The development of an efficient chemoenzymatic route for the synthesis of optically active dihydroxy cyclopenta[b]naphthalenones; (+)-1,4a-dihydroxy-4a,5,6,7,8,8a,9,9a-octahydro-1H-cyclopenta[b]naphthalen-2(4H)-one (+)-10 and (+)-1,8a-dihydroxy-4a,5,6,7,8,8a,9,9a-octahydro-1H-cyclopenta[b]naphthalen-2(4H)-one (+)-11 is described. Different lipases and esterases were tested in the enzymatic hydrolysis of the corresponding acetates (±)-4a-hydroxy-2-oxo-2,4,4a,5,6,7,8,8a,9,9a-decahydro-1H-cyclopenta[b]naphthalen-1-yl acetate (±)-8, (±)-8a-hydroxy-2-oxo-2,4,4a,5,6,7,8,8a,9,9a-decahydro-1H-cyclopenta[b]naphthalen-1-yl acetate (±)-9, CRL (Candida Rugosa Lipase) and PLE (Pig Liver Esterase) were found to be the most effectual enzymes; for (?)-8 by 47% ee with the corresponding dihydroxy; (+)-10 by 98% ee in the presence of CRL; whereas, (?)-8 was obtained with 40% ee with the corresponding dihydroxy, (+)-10 with 58% ee in the PLE hydrolysis. It was concluded that CRL was the best biocatalyst for the substrate (±)-8. Moreover, enzymatic resolution in the presence of CRL yields, (?)-9 with 46% ee with the corresponding dihydroxy derivative; (+)-11 with 98% ee; however, in the presence of PLE, yields (?)-9 with 36% ee as well as the related dihydroxy derivative; (+)-11 with 49% ee respectively. The study concluded that CRL is the best biocatalyst for compounds (±)-8 and (±)-9.
Synergistic Catalysis: Metal/Proton-Catalyzed Cyclization of Alkynones Toward Bicyclo[3.n.1]alkanones
Zhu, Shifa,Zhang, Qiaohui,Chen, Kai,Jiang, Huanfeng
supporting information, p. 9414 - 9418 (2015/08/06)
A highly efficient and practical synergistically metal/proton-catalyzed Conia-ene reaction for the synthesis of bicyclo[3.n.1]alkanones has been developed. This synergistic catalysis was successfully utilized in modifying natural compounds such as methyl dihydrojasmonate, α,β-thujone, and 5α-cholestan-3-one. Furthermore, the bridged carbonyl group of bicyclo[3.2.1]alkanones could be easily attacked by nucleophiles to give the ring-opened cycloheptenone products or bicyclo[4.2.1]amide in excellent yields. These reactions provide rapid access to a diverse range of cyclic structures from simple starting materials or naturally occurring compounds. A highly efficient and practical synergistically metal/proton-catalyzed Conia-ene reaction for the synthesis of bicyclo[3.n.1]alkanones has been developed. The reaction was successfully utilized in modifying natural compounds such as methyl dihydrojasmonate, α,β-thujone, and 5α-cholestan-3-one. Furthermore, the bicyclo[3.2.1]alkanones can be ring-opened by nucleophiles to give the corresponding products in excellent yields.
Silver-free activation of ligated gold(I) chlorides: The use of [Me3NB12Cl11]- as a weakly coordinating anion in homogeneous gold catalysis
Wegener, Michael,Huber, Florian,Bolli, Christoph,Jenne, Carsten,Kirsch, Stefan F.
, p. 1328 - 1336 (2015/02/05)
Phosphane and N-heterocyclic carbene ligated gold(I) chlorides can be effectively activated by Na[Me3NB12Cl11] (1) under silver-free conditions. This activation method with a weakly coordinating closo-dodecaborate anion was shown to be suitable for a large variety of reactions known to be catalyzed by homogeneous gold species, ranging from carbocyclizations to heterocyclizations. Additionally, the capability of 1 in a previously unknown conversion of 5-silyloxy-1,6-allenynes was demonstrated.
Efficient control for the cationic platinum(II)-catalyzed concise synthesis of two types of fused carbocycles with angular oxygen functionality
Kusama, Hiroyuki,Watanabe, Eiichi,Ishida, Kento,Iwasawa, Nobuharu
supporting information; experimental part, p. 2273 - 2277 (2012/06/30)
Double trouble: An efficient method for the preparation of two types of synthetically useful bicyclo[5.4.0]undecanes with an angular oxygen functionality was realized starting from easily available substrates; this method was based on the [3+2] cycloaddit
