scholarly journals Tandem catalysis of ring-closing metathesis/atom transfer radical reactions with homobimetallic ruthenium–arene complexes

2010 ◽  
Vol 6 ◽  
pp. 1167-1173 ◽  
Author(s):  
Yannick Borguet ◽  
Xavier Sauvage ◽  
Guillermo Zaragoza ◽  
Albert Demonceau ◽  
Lionel Delaude
Keyword(s):  
Mixed Valence ◽  
Active Species ◽  
Radical Reactions ◽  
Catalyst Precursor ◽  
Atom Transfer ◽  
Tandem Catalysis ◽  
Ring Closing Metathesis ◽  
Experimental Conditions ◽  
Mixed Valence Compound ◽  
The Individual

The tandem catalysis of ring-closing metathesis/atom transfer radical reactions was investigated with the homobimetallic ruthenium–indenylidene complex [(p-cymene)Ru(μ-Cl)3RuCl(3-phenyl-1-indenylidene)(PCy3)] (1) to generate active species in situ. The two catalytic processes were first carried out independently in a case study before the whole sequence was optimized and applied to the synthesis of several polyhalogenated bicyclic γ-lactams and lactones from α,ω-diene substrates bearing trihaloacetamide or trichloroacetate functionalities. The individual steps were carefully monitored by 1H and 31P NMR spectroscopies in order to understand the intimate details of the catalytic cycles. Polyhalogenated substrates and the ethylene released upon metathesis induced the clean transformation of catalyst precursor 1 into the Ru(II)–Ru(III) mixed-valence compound [(p-cymene)Ru(μ-Cl)3RuCl2(PCy3)], which was found to be an efficient promoter for atom transfer radical reactions under the adopted experimental conditions.

scholarly journals Synthesis of Stilbene and Chalcone Inhibitors of Influenza A Virus by SBA-15 Supported Hoveyda-Grubbs Metathesis

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 983 ◽  
Author(s):  
Bruno Mattia Bizzarri ◽  
Angelica Fanelli ◽  
Davide Piccinino ◽  
Marta De Angelis ◽  
Camilla Dolfa ◽  
...  
Keyword(s):  
Biological Activity ◽  
Influenza A Virus ◽  
Influenza A ◽  
Early Stage ◽  
Active Species ◽  
The Novel ◽  
Santa Barbara ◽  
Ring Closing Metathesis ◽  
Experimental Conditions ◽  
Mesoporous Silicate

Stilbene and chalcone derivatives with biological activity against influenza A virus have been synthesized by self-, cross-, and ring-closing metathesis procedures. The reactions were performed under environmentally friendly conditions using the second generation Hoveyda-Grubbs catalyst Aquamet SiPr after immobilization on Santa Barbara Amorphous mesoporous silicate SBA-15. Irrespective from the experimental conditions, the heterogeneous catalyst showed activity and selectivity comparable than the homogeneous counterpart for at least six successive runs without appreciable leaching of the active species. An appreciable antiviral activity against influenza A virus for some of the novel derivatives were observed, mainly involving the early stage of the virus-replication life-cycle.

Ruthenium catalysts bearing N-heterocyclic carbene ligands in atom transfer radical reactions

2003 ◽  
Vol 44 (32) ◽  
pp. 6011-6015 ◽  
Author(s):  
Aurore Richel ◽  
Sébastien Delfosse ◽  
Cédric Cremasco ◽  
Lionel Delaude ◽  
Albert Demonceau ◽  
...  
Keyword(s):  
Ruthenium Catalysts ◽  
Radical Reactions ◽  
Atom Transfer ◽  
Carbene Ligands

Comment on “Pressure-induced structural and valence transition in AgO” by C. Hou, J. Botana, X. Zhang, X. Wang and M. Miao, Phys. Chem. Chem. Phys., 2016, 18, 15322

2016 ◽  
Vol 18 (46) ◽  
pp. 31973-31974 ◽  
Author(s):  
Mariana Derzsi ◽  
Wojciech Grochala
Keyword(s):  
Electronic Structure ◽  
Recent Article ◽  
Theoretical Study ◽  
Mixed Valence ◽  
Chem Phys ◽  
External Pressure ◽  
Valence Transition ◽  
Mixed Valence Compound ◽  
Phys Chem Chem Phys

The recent article by Hou et al. has focused on a theoretical study of mixed valence compound AgO in order to elucidate the nature of the electronic structure of this system as a function of external pressure.

scholarly journals Tandem Radical Reactions and Ring-Closing Metathesis. Application in the Synthesis of Cyclooctenes.

ChemInform ◽  
2003 ◽  
Vol 34 (49) ◽  
Author(s):  
Mukund P. Sibi ◽  
Mona Aasmul ◽  
Hikaru Hasegawa ◽  
Thangaiah Subramanian
Keyword(s):  
Radical Reactions ◽  
Ring Closing Metathesis ◽  
Tandem Radical Reactions

Singlet carbenes as mimics for transition metals: synthesis of an air stable organic mixed valence compound [M2(C2)+˙; M = cyclic(alkyl)(amino)carbene]

2014 ◽  
Vol 1 (4) ◽  
pp. 351-354 ◽  
Author(s):  
Liqun Jin ◽  
Mohand Melaimi ◽  
Liu Liu ◽  
Guy Bertrand
Keyword(s):  
Transition Metals ◽  
Radical Cation ◽  
Mixed Valence ◽  
Ethynyl Radical ◽  
Mixed Valence Compound ◽  
Singlet Carbenes

A bis-carbene-stabilized ethynyl radical cation, a purely organic mixed valence compound, is indefinitely air stable.

Heat Transfer in Reciprocating Planar Curved Tube With Piston Cooling Application

2005 ◽  
Vol 128 (1) ◽  
pp. 219-229 ◽  
Author(s):  
Shyy Woei Chang ◽  
Yao Zheng
Keyword(s):  
Heat Transfer ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Interactive Effects ◽  
Experimental Conditions ◽  
Nusselt Numbers ◽  
Curved Tube ◽  
The Individual ◽  
Cooling Passage ◽  
Piston Cooling

This paper describes an experimental study of heat transfer in a reciprocating planar curved tube that simulates a cooling passage in piston. The coupled inertial, centrifugal, and reciprocating forces in the reciprocating curved tube interact with buoyancy to exhibit a synergistic effect on heat transfer. For the present experimental conditions, the local Nusselt numbers in the reciprocating curved tube are in the range of 0.6–1.15 times of static tube levels. Without buoyancy interaction, the coupled reciprocating and centrifugal force effect causes the heat transfer to be initially reduced from the static level but recovered when the reciprocating force is further increased. Heat transfer improvement and impediment could be superimposed by the location-dependent buoyancy effect. The empirical heat transfer correlation has been developed to permit the evaluation of the individual and interactive effects of inertial, centrifugal, and reciprocating forces with and without buoyancy interaction on local heat transfer in a reciprocating planar curved tube.

scholarly journals ‘What would you do if you were me, doctor?’: randomised trial of psychiatrists' personal v. professional perspectives on treatment recommendations

2010 ◽  
Vol 197 (6) ◽  
pp. 441-447 ◽  
Author(s):  
Rosmarie Mendel ◽  
Johannes Hamann ◽  
Eva Traut-Mattausch ◽  
Markus Bühner ◽  
Werner Kissling ◽  
...  
Keyword(s):  
Watchful Waiting ◽  
Randomised Trial ◽  
Specific Treatment ◽  
The Self ◽  
Personal Perspective ◽  
Experimental Conditions ◽  
Appropriate Treatment ◽  
Professional Perspectives ◽  
Oral Antipsychotic ◽  
The Individual

BackgroundIf patients are unsure whether a specific treatment is really good for them, they often pose the question, ‘What would you do if you were me, doctor?’ Patients want their psychiatrists to put themselves in their shoes and not to give a ‘standard recommendation’.AimsTo study whether this question really leads psychiatrists to reveal their personal preferences.MethodRandomised experimental study with 515 psychiatrists incorporating two decision scenarios (depression scenario: antidepressant v. watchful waiting; schizophrenia scenario: depot v. oral antipsychotic) and three experimental conditions (giving a recommendation to a patient asking, ‘What would you do if you were me, doctor?’; giving a regular recommendation to a patient without being asked this question; and imagining being ill and deciding for yourself). Main outcome measures were the treatments chosen or recommended by physicians.ResultsPsychiatrists choosing treatment for themselves predominantly selected other treatments (mostly watchful waiting and oral antipsychotics respectively) than what psychiatrists recommended to patients when asked in the ‘regular recommendation role’ (i.e. antidepressant and depot respectively). Psychiatrists in the ‘what-would-you-do role’ gave recommendations similar to the ‘regular recommendation role’ (depression scenario: χ2 = 0.12, P = 0.73; schizophrenia scenario: χ2 = 2.60, P = 0.11) but distinctly different from the ‘self role’.ConclusionsThe question ‘What would you do if you were me, doctor?’ does not motivate psychiatrists to leave their professional recommendation role and to take a more personal perspective. Psychiatrists should try to find out why individuals are asking this question and, together with the individual, identify the most appropriate treatment option.

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