- Depolymerization of Hydroxylated Polymers via Light-Driven C-C Bond Cleavage
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The accumulation of persistent plastic waste in the environment is widely recognized as an ecological crisis. New chemical technologies are necessary both to recycle existing plastic waste streams into high-value chemical feedstocks and to develop next-generation materials that are degradable by design. Here, we report a catalytic methodology for the depolymerization of a commercial phenoxy resin and high molecular weight hydroxylated polyolefin derivatives upon visible light irradiation near ambient temperature. Proton-coupled electron transfer (PCET) activation of hydroxyl groups periodically spaced along the polymer backbone furnishes reactive alkoxy radicals that promote chain fragmentation through C-C bond β-scission. The depolymerization produces well-defined and isolable product mixtures that are readily diversified to polycondensation monomers. In addition to controlling depolymerization, the hydroxyl group modulates the thermomechanical properties of these polyolefin derivatives, yielding materials with diverse properties. These results demonstrate a new approach to polymer recycling based on light-driven C-C bond cleavage that has the potential to establish new links within a circular polymer economy and influence the development of new degradable-by-design polyolefin materials.
- Nguyen, Suong T.,McLoughlin, Elizabeth A.,Cox, James H.,Fors, Brett P.,Knowles, Robert R.
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supporting information
p. 12268 - 12277
(2021/08/23)
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- A facile and efficient method for synthesis of β-iodocarboxylates from terminal epoxides
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A facile and efficient method has been developed for synthesis of β-iodocarboxylates in the presences of Ph3P/I2. Starting from epoxides, a series of β-iodocarboxylate compounds can be directly obtained in toluene media with excellent yields. Moreover, the method was successfully applied for the late-stage modification of natural products, such as isosteviol and vincamine derivatives, achieving the corresponding β-iodocarboxylates in good yields.
- Zhu, Ye-Fu,Wei, Bo-Le,Wang, Wen-Qiong,Xuan, Li-Jiang
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supporting information
(2019/11/26)
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- Synthesis and evaluation of 4-(2-hydroxypropyl)piperazin-1-yl) derivatives as Hsp90 inhibitors
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We previously reported 4-(3-((6-bromonaphthalen-2-yl)oxy)-2-hydroxypropyl)-N,N-dimethylpiperazine-1-sulfonamide (1) as a novel heat shock protein 90 inhibitor with moderate activity. In our ongoing efforts for the discovery of Hsp90 modulators we undertake structural investigations on 1. Series of the titled compound were designed, synthesized and evaluated. We have found that compounds with a hydroxyl group at C-4 of the aryl ring on the piperazine moiety possess Hsp90 inhibition properties. Compound 6f with improved activity could be further developed and optimized as Hsp90 inhibitor.
- Cherfaoui, Bahidja,Guo, Tian-Kun,Sun, Hao-Peng,Cheng, Wei-Lin,Liu, Fang,Jiang, Fen,Xu, Xiao-Li,You, Qi-Dong
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supporting information
p. 2423 - 2432
(2016/05/24)
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- Synthesis of new N-acryl-1-amino-2-phenylethanol and N-acyl-1-amino-3- aryloxypropanols and evaluation of their antihyperlipidemic, LDL-oxidation and antioxidant activity
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As a part of our drug discovery program, we identified an alkaloidal amide i.e. Aegeline (V) isolated from the leaves of Aegle marmelos as a dual acting agent (antihyperlipidemic and antihyperglycemic). In continuation of this program, we synthesized new N-acyl-1-amino-2-alcohols (N-acrylated-1-amino-2- phenylethanol and N-acylated-1-amino-3-aryloxypropanols) via Ritter reaction and screened for their in-vivo antihyperlipdemic activity in Triton induced hyperlipidemia model, LDL-oxidation and antioxidant activity. Compounds 3, 11 and 13 showed good antihyperlipidemic activity, LDL-oxidation as well as antioxidant activity and comparable activity with marketed antidyslipidemic drug.
- Sarkar, Satinath,Sonkar, Ravi,Bhatia, Gitika,Tadigoppula, Narender
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p. 135 - 144
(2014/05/20)
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- A new synthesis of sultams from amino alcohols
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The base-mediated cyclization of N,O-dimesylate derivatives of cyclic and acyclic amino alcohols provides a simple access to five- and six-member sultams: isothiazolidine-1,1-dioxides and thiazinane-1,1-dioxides respectively.
- Lad, Nitin,Sharma, Rajiv,Marquez, Victor E.,Mascarenhas, Malcolm
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p. 6307 - 6309
(2013/11/06)
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- SUBSTITUTED DIHYDRO AND TETRAHYDRO OXAZOLOPYRIMIDINONES, PREPARATION AND USE THEREOF
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The present invention relates to a series of substituted dihydro and tetrahydro oxazolopyrimidinones, specifically, to a series of 2-substituted-2,3-dihydro-oxazolo[3,2-a]pyrimidin-7-ones and 2-substituted-2,3,5,6-tetra-hydro-oxazolo[3,2-a]pyrimidin-7-ones of formula (I): Wherein p, n, X, Y, R1, R2, R3, R4, R5, R6, R7 and R8 are as defined herein. This invention also relates to methods of making these compounds including novel intermediates. The compounds of this invention are modulators of metabotropic glutamate receptors (mGluR), particularly, mGluR2 receptor. Therefore, the compounds of this invention are useful as pharmaceutical agents, especially in the treatment and/or prevention of a variety of central nervous system disorders (CNS), including but not limited to acute and chronic neurodegenerative conditions, psychoses, convulsions, anxiety, depression, migraine, pain, sleep disorders and emesis.
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Page/Page column 26
(2010/04/23)
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- Bispidine antiarrhythmic compounds
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There is provided a compound of formula I, wherein R1, R2, R9, R10, R11, R12, X, A and B have meanings given in the description, which are useful in the prophylaxis and in the treatment of arrhythmias, in particular atrial and ventricular arrhythmias.
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- Epoxy-acrylic macromolecular compounds on the basis of phenol and para-alkyl substituted phenol
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Some phenolic glycidyl ethers and suitable acrylic monomers on the basis of phenol and para-alkyl [-CH3, -C(CH3)3, -C9H19] substituted phenols were synthesized and characterized. The monomers were thermally polymerized in the presence of benzoyl peroxide. The polymerization reaction was studied by viscometry, as well as by curing process. The synthesized polymers degrade statistically by a radical mechanism. The apparent thermal stability is higher for para-tert-butylphenol epoxy-acrylic polymer and lower for phenol epoxy-acrylic polymer.
- Ca?caval, Constantin N.,Ro?u, Dan
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p. 731 - 737
(2007/10/03)
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- Piperidine derivatives
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Compounds of formula (I): wherein:, R represents H or a mono- or poly- carboxylic acyl group;, R1 represents H or a carboxylic ester moiety;, R2 represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or an aralkyl group, said groups being optionally substituted, or R2 represents a carboxylic ester moiety;, n = 1 - 4;, Y is O or S;, and esters thereof, are useful as heat and photo- stabilisers for polymeric materials.
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- Search for anxiolytic activity starting from a myorelaxant structure. tert Butylphenol derivatives
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Twenty eight compounds (10 phenoxypropanediols, 9 epoxides and 9 phenoxymethyloxazolidinones carrying on the benzene ring 1 or 2 tert. butyl groups and sometimes an allyl group) were investigated for myorelaxant and anxiolytic activities. These actions can be dissociated; 2 compounds - 5[(2 tert butylphenoxy)methyl]oxazolidin 2 one (R 1297) and 5 [(2 allyl 5 tert. butylphenoxy)methyl]oxazolidin 2 one (R 1377) - lack the former while being very effective in the 4 plate and electric battle tests. They have no sedative action and are virtually devoid of toxicity.
- Auzou,Rips,Derappe,Peyroux
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p. 548 - 554
(2007/10/07)
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