- Reduction over Condensation of Carbonyl Compounds through a Transient Hemiaminal Intermediate Using Hydrazine
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Reduction of carbonyl moieties to the corresponding alcohol using simply hydrazine hydrate has been considerably unfeasible until now due to the well-known condensation reaction. However, herein, we report that using an excess of 20-fold equivalents, the reduction proceeds in excellent yields. 1H NMR study of the reaction and density functional theory (DFT) calculations indicate that the final fate of the hemiaminal intermediate is crucial to obtain the alcohol or the hydrazone.
- Vilches-Herrera, Marcelo,Gallardo-Fuentes, Sebastián,Aravena-Opitz, Mauricio,Yá?ez-Sánchez, Mauricio,Jiao, Haijun,Holz, Jens,B?rner, Armin,Lühr, Susan
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p. 9213 - 9218
(2020/08/14)
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- Catalyst- And Silane-Controlled Enantioselective Hydrofunctionalization of Alkenes by Cobalt-Catalyzed Hydrogen Atom Transfer and Radical-Polar Crossover
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The catalytic enantioselective synthesis of tetrahydrofurans, which are found in the structures of many biologically active natural products, via a transition-metal-catalyzed hydrogen atom transfer (TM-HAT) and radical-polar crossover (RPC) mechanism is described herein. Hydroalkoxylation of nonconjugated alkenes proceeded efficiently with excellent enantioselectivity (up to 94% ee) using a suitable chiral cobalt catalyst, N-fluoro-2,4,6-collidinium tetrafluoroborate, and diethylsilane. Surprisingly, the absolute configuration of the product was highly dependent on the steric hindrance of the silane. Slow addition of the silane, the dioxygen effect on the solvent, thermal dependence, and DFT calculation results supported the unprecedented scenario of two competing selective mechanisms. For the less-hindered diethylsilane, a high concentration of diffused carbon-centered radicals invoked diastereoenrichment of an alkylcobalt(III) intermediate by a radical chain reaction, which eventually determined the absolute configuration of the product. On the other hand, a more hindered silane resulted in less opportunity for a radical chain reaction, instead facilitating enantioselective kinetic resolution during the late-stage nucleophilic displacement of the alkylcobalt(IV) intermediate.
- Ebisawa, Kousuke,Izumi, Kana,Ooka, Yuka,Kato, Hiroaki,Kanazawa, Sayori,Komatsu, Sayura,Nishi, Eriko,Shigehisa, Hiroki
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supporting information
p. 13481 - 13490
(2020/09/02)
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- Trivalent Rare-Earth Metal Amide Complexes as Catalysts for the Hydrosilylation of Benzophenone Derivatives with HN(SiHMe2)2 by Amine-Exchange Reaction
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The rare-earth metal complexes Ln(L1)[N(SiHMe2)2](thf) (Ln=La, Ce, Y; L1=N,N′′-bis(pentafluorophenyl)diethylenetriamine dianion) were synthesized by treating Ln[N(SiHMe2)2]3(thf)2 with L1H2. The lanthanum and cerium derivatives are active catalysts for the hydrosilylation of benzophenone derivatives with HN(SiHMe2)2. An amine-exchange reaction was revealed as a key step of the catalytic cycle, in which Ln?Si?H β-agostic interactions are proposed to promote insertion of the carbonyl moiety into the Si?H bond.
- Shinohara, Koichi,Tsurugi, Hayato,Anwander, Reiner,Mashima, Kazushi
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supporting information
p. 14130 - 14136
(2020/10/06)
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- Immobilized palladium nanoparticles on a cyclodextrin-polyurethane nanosponge (Pd-CD-PU-NS): An efficient catalyst for cyanation reaction in aqueous media
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Immobilized palladium nanoparticles on a cyclodextrin-polyurethane nanosponge (Pd-CD-PU-NS) were found to be an efficient heterogeneous catalyst in the cyanation reaction of aryl halides in aqueous media. This catalyst system is containing palladium nanoparticles with a size of ~7 nm. Moreover, the CD-PU-NS support formed microsphere-shaped structures with a size of ~100–200 nm. The TEM images show that Pd nanoparticles were formed in near spherical shape morphology and were immobilized in the structure of the CD-PU-NS support. Under our optimized reaction conditions, aryl cyanides were obtained in high yields in the presence of the Pd-CD-PU-NS catalyst. Our results demonstrated that the Pd-CD-PU-NS catalyst is highly effective in the cyanation reaction in aqueous media. Furthermore, the catalyst could be simply extracted from the reaction mixture, providing an efficient methodology for the synthesis of aryl cyanides. The Pd-CD-PU-NS catalyst could be recycled four times with almost consistent catalytic efficiency.
- Khajeh Dangolani, Soheila,Sharifat, Sara,Panahi, Farhad,Khalafi-Nezhad, Ali
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supporting information
p. 256 - 265
(2019/06/07)
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- Hole transport-material based on ether structure, and preparation method and application thereof
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The invention discloses a novel hole-transport material, and a preparation method and application thereof. The hole-transport material uses bis(diphenylmethane) connected with oxygen or sulfur as a core and diphenylamine substituted by an alkoxy group or
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-
Paragraph 0066; 0068; 0070-0072
(2019/11/20)
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- Methane-perylene diimide-based small molecule acceptors for high efficiency non-fullerene organic solar cells
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We report perylene diimide (PDI) small molecules based on diphenylmethane, triphenylmethane, and tetraphenylmethane cores, named PM-PDI2, PM-PDI3 and PM-PDI4, respectively. The OSC performances of PM-PDI3 and PM-PDI4 are comparable. The PM-PDI3 based device with PDBT-T1 as the donor achieved a highest power conversion efficiency (PCE) of 7.58% along with a high open-circuit voltage (VOC) of 0.98 V, a short-circuit current density (JSC) of 11.02 mA cm-2 and a high fill factor (FF) of 69.9%, a 1.32 times boost in PCE with respect to the PM-PDI2 based control device (3.26%). The high photovoltaic performance of the PM-PDI3 based device can be attributed to its relatively high-lying LUMO level, complementary absorption spectra with the polymer donor material PDBT-T1, relatively favorable morphology and improved exciton dissociation and charge collection efficiency. A PCE of 7.58% is among the highest efficiency of phenyl-methane as core based non-fullerene organic solar cells. Overall, this work provides a new approach to enhance the performance of non-fullerene acceptors.
- Li, Gang,Yang, Wenbin,Wang, Shuaihua,Liu, Tao,Yan, Cenqi,Zhang, Yu,Li, Dandan,Wang, Xinyu,Hao, Pin,Li, Jiewei,Huo, Lijun,Yan, He,Tang, Bo
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supporting information
p. 10901 - 10907
(2019/09/19)
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- AlCl3 catalyzed coupling of: N-benzylic sulfonamides with 2-substituted cyanoacetates through carbon-nitrogen bond cleavage
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A new cross-coupling reaction of N-benzylic sulfonamides with 2-substituted cyanoacetates for the synthesis of 2-substituted benzylbenzene was reported. In the presence of AlCl3, a broad range of N-benzylic sulfonamides reacted smoothly with 2-substituted cyanoacetates to afford structurally diverse benzylbenzenes in moderate to excellent yields. The conversion could be enlarged to gram-scale efficiently. The practicability of this approach was further manifested in the synthesis of a related bioactive agent with high anti-inflammatory activity.
- Hu, Chen,Hong, Gang,Qian, Xiaofei,Kim, Kwang Rim,Zhu, Xiaoyan,Wang, Limin
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supporting information
p. 4984 - 4991
(2017/07/10)
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- Synthesis and biological evaluation of aryloxyacetamide derivatives as neuroprotective agents
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A series of new aryloxyacetamide derivatives 10a-s and 14a-m are designed and synthesized. Their protective activities against the glutamate-induced cell death were investigated in differentiated rat pheochromocytoma cells (PC12 cells). Most compounds exhibited neuroprotective effects, especially for 10m, 10r, 14b and 14c, which showed potential protection of PC12 cells at three doses (0.1, 1.0, 10 μM). MTT assay, Hoechst 33342/PI double staining, and high content screening (HCS) revealed that pretreatment of the cells with 10m, 10r, 14b and 14c has significantly decreased the extent of cell apoptosis in a dose-dependent manner. The results of western blot analysis demonstrated these compounds suppressed apoptosis of glutamate-induced PC12 cells via caspase-3 pathway. These compounds can be lead compounds for further discovery of neuroprotective agents for treating cerebral ischemic stroke. Basic structure-activity relationships are also presented.
- Zhong, Yan,Xu, Yi,Zhang, Ai-Xia,Li, Xiao-Feng,Xu, Zhao-Ying,Li, Ping,Wu, Bin
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supporting information
p. 2526 - 2530
(2016/07/07)
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- Co(III)-Catalyzed Synthesis of Quinazolines via C-H Activation of N-Sulfinylimines and Benzimidates
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C-H activation of arenes has been established as an important strategy for heterocycle synthesis via annulations between arenes and unsaturated coupling partners. However, nitriles failed to act as such a coupling partner. Dioxazolones have been employed as a synthon of nitriles, and subsequent coupling with arenes such as N-sulfinylimines and benzimidates bearing a functionalizable directing group provided facile access to two classes of quinazolines under Co(III)-catalysis.
- Wang, Fen,Wang, He,Wang, Qiang,Yu, Songjie,Li, Xingwei
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p. 1306 - 1309
(2016/04/01)
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- Elucidation of structural elements for selectivity across monoamine transporters: Novel 2-[(diphenylmethyl)sulfinyl]acetamide (modafinil) analogues
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2-[(Diphenylmethyl)sulfinyl]acetamide (modafinil, (±)-1) is a unique dopamine uptake inhibitor that binds the dopamine transporter (DAT) differently than cocaine and may have potential for the treatment of psychostimulant abuse. To further investigate structural requirements for this divergent binding mode, novel thio- and sulfinylacetamide and ethanamine analogues of (±)-1 were synthesized wherein (1) the diphenyl rings were substituted with methyl, trifluoromethyl, and halogen substituents and (2) substituents were added to the terminal amide/amine nitrogen. Halogen substitution of the diphenyl rings of (±)-1 gave several amide analogues with improved binding affinity for DAT and robust selectivity over the serotonin transporter (SERT), whereas affinity improved at SERT over DAT for the p-halo-substituted amine analogues. Molecular docking studies, using a subset of analogues with DAT and SERT homology models, and functional data obtained with DAT (A480T) and SERT (T497A) mutants defined a role for TM10 in the substrate/inhibitor S1 binding sites of DAT and SERT.
- Okunola-Bakare, Oluyomi M.,Cao, Jianjing,Kopajtic, Theresa,Katz, Jonathan L.,Loland, Claus J.,Shi, Lei,Newman, Amy Hauck
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p. 1000 - 1013
(2014/03/21)
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- POTENT AND SELECTIVE INHIBITORS OF MONOAMINE TRANSPORTERS; METHOD OF MAKING; AND USE THEREOF
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Disclosed herein are bisarylmethylthioacetamides and bisarylmethylthioethylamines useful as inhibitors of monoamine transporters. The compounds are potent and/or selective inhibitors of dopamine (DA), serotonin (5-HT), and/or norepinephrine (NE) reuptake via their respective transporters, DAT, SERT and NET. Also disclosed are methods for eliciting a wake-promoting or cognitive or attention enhancing effect and for treating substance use disorders, attention deficit (hyperactivity) disorder, depressive disorders, bipolar disorder or other neuropsychiatric disorders sleep disorders or cognitive impairment using the compounds.
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Paragraph 0072
(2014/09/29)
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- SARs at the monoamine transporters for a novel series of modafinil analogues
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A series of modafinil (1) analogues were synthesized wherein (1) para-halo-substitutents were added to the aryl rings, (2) the sulfoxide function was removed, and (3) the primary amide group was replaced with secondary and tertiary amides and amines to investigate the effects of these chemical modifications on dopamine transporter, serotonin transporter, and norepinephrine transporter binding. In addition, the locomotor-stimulant effects in mice of (±)-modafinil (1), its R-and S-enantiomers, and its para-chloro sulfinylacetamide analogue (5c) were compared to those of cocaine.
- Cao, Jianjing,Prisinzano, Thomas E.,Okunola, Oluyomi M.,Kopajtic, Theresa,Shook, Matthew,Katz, Jonathan L.,Newman, Amy Hauck
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supporting information; experimental part
p. 48 - 52
(2011/04/22)
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- N-heterocyclic carbene-catalyzed cross-coupling of aromatic aldehydes with activated alkyl halides
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N-Heterocyclic carbene-catalyzed umpolung of aldehydes followed by their interception with diarylbromomethanes has been reported. This conceptually novel transition-metal-free cross-coupling of aldehydes with alkyl halides works well at low catalyst loadings and under mild reaction conditions leading to the formation of diaryl acetophenone derivatives in good yields. In addition, α-halo ketones and esters can also be used as aldehyde reaction partners.
- Padmanaban, Mohan,Biju, Akkattu T.,Glorius, Frank
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supporting information; experimental part
p. 98 - 101
(2011/03/19)
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- Enantioselective catalytic α-alkylation of aldehydes via an S N1 pathway
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Primary aminothiourea derivatives are shown to catalyze enantioselective alkylation of α-arylpriopionaldehdyes with diarylbromomethane. Evidence for a stepwise, S N1 mechanism in the substitution reaction induced by anion binding to the catalyst is provided by catalyst structure-activity studies, kinetic isotope effects, linear free-energy relationship studies, and competition experiments.
- Brown, Adam R.,Kuo, Wen-Hsin,Jacobsen, Eric N.
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supporting information; experimental part
p. 9286 - 9288
(2010/11/03)
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- Modulation of spectrokinetic properties of o-quinonoid reactive intermediates by electronic factors: Time-resolved laser flash and steady-state photolysis investigations of photochromic 6- and 7-arylchromenes
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A ready synthetic accessibility of a series of 6- and 7-arylchromenes via Pd0-catalyzed Suzuki coupling protocol has permitted a comprehensive investigation of the thermal decay behavior of a broad set of photogenerated o-quinonoid reactive intermediates. It is shown that substantial mesomeric effect between the benzopyran nucleus and the aryl ring at C6 or C7 position of the former renders significant absorption beyond 350 nm such that they are readily photoactivated to yield colored o-quinonoid intermediates. The absorption spectra of the latter are found to be strongly influenced by the substituents on C2-, C6- and C7-aryl rings; indeed the colored absorptions can be conveniently tuned by appropriate choice of substituents. The thermal decay (bleaching phenomenon), which is important from the point of view of their application in ophthalmic lenses, was investigated in each case by μs-ms as well as real-time absorption spec-troscopy. By careful experimentation, we have extracted the decay rate constants for Z,E and E,E o-quinonoid isomers of all 6- and 7-arylchromenes in an attempt to establish a correlation between the electronic attributes with their thermokinetic behavior. From a combined analysis of μs-ms (laser flash) and real-time kinetic data, it is shown that the colored o-quinonoid intermediates decay faster when the C2-aryl and C6-/C7-aryl rings contain electron-donating and electron-accepting groups, respectively. In the same vein, the decay was found to occur slowly for the reversed scenario, while intermediate decay rates are observed when both substituents are electron-donating. Thus, any substituent on the C2-aryl ring that contributes mesomerically to the development of charge on the quinonoid oxygen, and any substituent on the C6-/C7-aryl ring that exerts -I effect appear to expedite thermal decay. Furthermore, evidence is obtained for the first time from μs time-resolved laser-flash spectroscopy for the formation and characterization of the trans,cis (E,Z) o-quinonoid isomer, which has heretofore eluded spectral characterization in the photochromic phenomena of pyrans.
- Moorthy, Jarugu Narasimha,Koner, Apurba L.,Samanta, Subhas,Roy, Ankur,Nau, Werner M.
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supporting information; experimental part
p. 4289 - 4300
(2009/12/07)
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- Mapping the active site in a chemzyme: Diversity in the N-substituent in the catalytic asymmetric aziridination of imines
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(Chemical Equation Presented) The active site of the aziridination catalyst derived from either the VANOL or VAPOL ligand and B(OPh)3 is larger than expected and can accommodate not only significant substitution on the diarylmethyl unit of the imine but also that alkyl (but not perfluorylalkyl) substituents on the aryl groups lead to enhanced rates and enantioselection. The screen of diarylmethyl N-substituents on the imine revealed that the 3,5-di-tert-butyldianisylmethyl group (BUDAM) gave exceptionally high asymmetric inductions for imines of aryl aldehydes.
- Zhang, Yu,Lu, Zhenjie,Desai, Aman,Wulff, William D.
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supporting information; experimental part
p. 5429 - 5432
(2009/06/20)
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- GLUCAGON RECEPTOR ANTAGONISTS, PREPARATION AND THERAPEUTIC USES
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The present invention discloses novel compounds of Formula (I), or pharmaceutically acceptable salts thereof, which have glucagon receptor antagonist or inverse agonist activity, as well as methods for preparing such compounds. In another embodiment, the invention discloses pharmaceutical compositions comprising compounds of Formula (I) as well as methods of using them to treat diabetic and other glucagon related metabolic disorders, and the like.
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Page/Page column 61
(2010/02/15)
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- AZETIDINECARBOXAMIDE DERIVATIVES AND THEIR USE IN THE TREATMENT OF CB1 RECEPTOR MEDIATED DISORDERS
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Compounds of formula (I) and their use in therapy, particularly for the treatment of a disorder mediated by CB1 receptors such as obesity: Formuila (I) wherein: R1 and R2 are independently selected from aryl; and R3 is hydrogen or alkyl; or a pharmaceutically acceptable salt or prodrug thereof, wherein at least one of R1 and R2 has a non-hydrogen substituent in the ortho-position(s) thereof relative to the point of attachment to the [-CH-0-] group.
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- Synthesis and preliminary testing of molecular wires and devices
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Presented here are several convergent synthetic routes to conjugated oligo(phenylene ethynylene)s. Some of these oligomers are free of functional groups, while others possess donor groups, acceptor groups, porphyrin interiors, and other heterocyclic interiors for various potential transmission and digital device applications. The syntheses of oligo(phenylene ethynylene)s with a variety of end groups for attachment to numerous metal probes and surfaces are presented. Some of the functionalized molecular systems showed linear, wire-like, current versus voltage (I(V)) responses, while others exhibited nonlinear I(V) curves for negative differential resistance (NDR) and molecular random access memory effects. Finally, the syntheses of functionalized oligomers are described that can form self-assembled monolayers on metallic electrodes that reduce the Schottky barriers. Information from the Schottky barrier studies can provide useful insight into molecular alligator clip optimizations for molecuar electronics.
- Tour, James M.,Rawlett, Adam M.,Kozaki, Masatoshi,Yao, Yuxing,Jagessar, Raymond C.,Dirk, Shawn M.,Price, David W.,Reed, Mark A.,Zhou, Chong-Wu,Chen, Jia,Wang, Wenyong,Campbell, Ian
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p. 5118 - 5134
(2007/10/03)
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- Structure-Property Relationships in Trimethylenemethane-Type Biradicals. 2. Synthesis and EPR Spectral Characterization of Dinitroxide Biradicals
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Several trimethylenemethane-type (TMM-type) dinitroxide biradicals have been prepared that differ in tert-butylaminoxylphenyl ring torsion angles by virtue of different steric demands of their "spin-protecting groups". In addition, the synthesis of a TMM-type dinitroxide having a planar π-system is reported. The synthetic route employed for the planar TMM-type biradical is general and should therefore expand the utility of TMM-type biradicals that are susceptible to bond torsions that attenuate exchange coupling. The compounds presented are designed to be effective to map out J-coupling/conformation space in TMM-type biradicals. EPR spectroscopic parameters (hfcc and D-values) were compared to determine if their values reflected differences in conformation in the series of biradicals. Interestingly, neither N- nor H-hfcc varied within our series of biradicals/ monoradicals in a regular fashion, indicating that there is no apparent relationship between N- or H-hfcc and conformation (as judged by molecular mechanics calculations). However, D-values, estimated from relative intensities of Δms = 1 and Δms = 2 transitions, are consistent with a varied degree of delocalization in the dinitroxides: smaller D-values for biradicals having smaller aryl torsions (and greater delocalization), and larger D-values for dinitroxides having greater aryl torsions (and less delocalization). All the biradicals studied, except 5, exhibited linear Curie plots. The linear Curie plots are consistent with both triplet ground-states and singlet-triplet degeneracies. Interestingly, dinitroxide 6 exhibited a linear Curie plot, despite the lack of a π-coupling fragment. Biradical 5, however, is a ground-state singlet species with the triplet lying about 140 cal/mol above the singlet.
- Shultz, David A.,Boal, Andrew K.,Lee, Hyoyoung,Farmer, Gary T.
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p. 4386 - 4396
(2007/10/03)
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- (1.1.1.1.1)PARACYCLOPHANE AND (1.1.1.1.1.1)PARACYCLOPHANE
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The first syntheses of (1.1.1.1.1)paracyclophane (1) and (1.1.1.1.1.1)paracyclophane (2) are described, featuring a trifluoroacetic acid promoted Friedel-Crafts cycloalkylation as the final step.
- Gribble, Gordon W.,Nutaitis, Charles F.
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p. 6023 - 6026
(2007/10/02)
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- Organometallic Compounds: Part I - Reduction of Benzophenones, 4,4'-Dialkoxydeoxybezoins, Benzils and Chalkones with Cyclohexylmethylmagnesium Bromide
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Cyclohexylmethylmagnesium bromide (I) reduces benzophenones (IIa-e) when reacted in a molar ratio of 4:1, to give mainly the corresponding benzhydrols (IIIa-e).A similar reaction of I with 4,4'-dialkoxydeoxybenzoins (IIf,g) results in the formation of carbinols (IIIf,g), the dehydration of which gives the corresponding stilbenes (VIIa,b).However, when benzil (IXa) (1 mol) is treated with I (4 mol), both reduction and addition reactions take place giving rise to a mixture of benzoin (Xa) and the addition product (IXa).A similar reaction of I with 4,4'-dimethoxybenzil (IXb) gives the addition product (XIb) together with anisic acid.
- Habashi, Abida,Tadros, Wadie,Shams, Hoda Zaki
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p. 659 - 662
(2007/10/02)
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