scholarly journals Generation of Bis(ferrocenyl)silylenes from Siliranes

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5917
Author(s):  
Yang Pan ◽  
Shogo Morisako ◽  
Shinobu Aoyagi ◽  
Takahiro Sasamori
Keyword(s):  
Transition Metal ◽  
Building Block ◽  
Building Blocks ◽  
Redox Behavior ◽  
Organosilicon Compounds ◽  
Design And Synthesis ◽  
Mild Conditions ◽  
Redox Active ◽  
Electronic Perturbation ◽  
Active Transition

Divalent silicon species, the so-called silylenes, represent attractive organosilicon building blocks. Isolable stable silylenes remain scarce, and in most hitherto reported examples, the silicon center is stabilized by electron-donating substituents (e.g., heteroatoms such as nitrogen), which results in electronic perturbation. In order to avoid such electronic perturbation, we have been interested in the chemistry of reactive silylenes with carbon-based substituents such as ferrocenyl groups. Due to the presence of a divalent silicon center and the redox-active transition metal iron, ferrocenylsilylenes can be expected to exhibit interesting redox behavior. Herein, we report the design and synthesis of a bis(ferrocenyl)silirane as a precursor for a bis(ferrocenyl)silylene, which could potentially be used as a building block for redox-active organosilicon compounds. It was found that the isolated bis(ferrocenyl)siliranes could be a bottleable precursor for the bis(ferrocenyl)silylene under mild conditions.

scholarly journals Phosphonate reagents and building blocks in the synthesis of bioactive compounds, natural products and medicines

2019 ◽  
Vol 91 (5) ◽  
pp. 811-838 ◽  
Author(s):  
Marian Mikołajczyk
Keyword(s):  
Building Block ◽  
Methyl Esters ◽  
Building Blocks ◽  
Biologically Active ◽  
Type I ◽  
Antiulcer Drug ◽  
Total Syntheses ◽  
Prostaglandin Analogues ◽  
Design And Synthesis ◽  
Neplanocin A

Abstract This account outlines the results obtained in the author’s laboratory on the application of phosphonates in the synthesis of various classes of biologically active cyclopentenones and cyclopentanones. In the first place two general methods for the synthesis of mono-, 1,2- and 1,4-dicarbonyl compounds are presented. The first is based on the use of α-phosphoryl sulfides in conjunction with the Horner reaction while in the second method the oxygenation reaction of α-phosphonate carbanion is a key step. The utility of these two approaches to 1,4-diketones as precursors of cyclopentenones was exemplified by the synthesis of dihydrojasmone and (Z)-jasmone. The use of simple phosphonates, α-phosphoryl sulfides and β- and γ-ketophosphonates as starting reagents in the synthesis of cyclopentanoid antibiotics (methylenomycin B, racemic desepoxy-4,5-didehydromethylenomycin, enantiomeric sarkomycins) is presented. The synthesis and reactivity of achiral 3-(phosphorylmethyl)cyclopent-2-enone and chiral diastereoisomeric camphor protected 3-(phosphorylmethyl)-4,5-dihydroxycyclopent-2-enones as building blocks is discussed as a platform for developing a new access to a variety of bioactive cyclopentenones. The utility and value of achiral phosphonate building block is demonstrated by the synthesis of racemic and enantiopure prostaglandin B1 methyl esters and enantiomeric phytoprostanes B1 type I and II. The range of biologically active compounds prepared from chiral diastereoisomeric cyclopentenone phosphonates is wider. Herein the total syntheses of the following target compounds are presented: enantiomeric isoterreins, natural (−)-neplanocin A and its unnatural (+)-enantiomer, anticancer prostaglandin analogues (enantiomers of TEI-9826, NEPP-11, iso-NEPP-11). The design and synthesis of racemic and four enantiopure stereoisomers of an antiulcer drug rosaprostol is also described.

Tailoring the redox-active transition metal content to enhance cycling stability in cation-disordered rock-salt oxides

2021 ◽  
Vol 43 ◽  
pp. 275-283
Author(s):  
Ke Zhou ◽  
Yining Li ◽  
Shiyao Zheng ◽  
Maojie Zhang ◽  
Chunyang Zhang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Rock Salt ◽  
Metal Content ◽  
Cycling Stability ◽  
Redox Active ◽  
Active Transition

scholarly journals Transition metal-free photodecarboxylative amination of redox-active esters with diazirines

2021 ◽  
Author(s):  
Vishala Maharaj ◽  
Preeti Chandrachud ◽  
Wen Che ◽  
Lukasz Wojtas ◽  
Justin Lopchuk
Keyword(s):  
Transition Metal ◽  
Blue Light ◽  
Electrophilic Amination ◽  
Metal Free ◽  
Active Esters ◽  
Mild Conditions ◽  
Redox Active ◽  
The Stability ◽  
Nitrogen Containing Compounds ◽  
Intense Research

Due to the prevalence of nitrogen-containing compounds in medicine, materials, and related fields, the search for general, mild methods for electrophilic amination remains an area of intense research. Diazirines have been recently demonstrated to serve as electrophilic amination reagents that afford diaziridines, versatile heterocycles that are readily transformed into amines, hydrazines, and a variety of nitrogen-containing heterocycles. Here we report the phosphine-mediated, photodecarboxylative amination of redox-active esters with diazirines. This method is transition metal-free, uses inexpensive photoactivators under mild conditions, and offers a significantly enhanced scope and yields for primary redox-active esters. Furthermore, the stability of diazirines to blue light (456 nm) is demonstrated, paving the way for further research into other photochemical amination methods with these unique heterocycles.

Low-density lipoprotein modification by normal, myeloperoxidase-deficient and NADPH oxidase-deficient granulocytes and the impact of redox active transition metal ions

Redox Report ◽  
2002 ◽  
Vol 7 (2) ◽  
pp. 111-119 ◽  
Author(s):  
Claudia E. Gerber ◽  
Gernot Bruchelt ◽  
Gerhard Ledinski ◽  
Joachim Greilberger ◽  
Dietrich Niethammer ◽  
...  
Keyword(s):  
Transition Metal ◽  
Nadph Oxidase ◽  
Metal Ions ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Transition Metal Ions ◽  
Low Density ◽  
Redox Active ◽  
Active Transition ◽  
The Impact

Oxidation State Analysis of a Four-Component Redox Series [Os(pap)2(Q)]nInvolving Two Different Non-Innocent Ligands on a Redox-Active Transition Metal

2011 ◽  
Vol 50 (15) ◽  
pp. 7090-7098 ◽  
Author(s):  
Dipanwita Das ◽  
Biprajit Sarkar ◽  
Tapan Kumar Mondal ◽  
Shaikh M. Mobin ◽  
Jan Fiedler ◽  
...  
Keyword(s):  
Transition Metal ◽  
Oxidation State ◽  
Redox Active ◽  
Active Transition ◽  
State Analysis

INTERACTIVE IIR SC MULTIRATE COMPILER APPLIED TO MULTISTAGE DECIMATOR DESIGN

2007 ◽  
Vol 16 (04) ◽  
pp. 517-525 ◽  
Author(s):  
PHILLIP N. CHEONG ◽  
R. P. MARTINS
Keyword(s):  
Building Block ◽  
Building Blocks ◽  
Automated Design ◽  
Operational Amplifiers ◽  
Efficient Synthesis ◽  
Design And Synthesis ◽  
Interactive Architecture ◽  
Specific Stage

This paper proposes an interactive architecture compiler for SC multirate circuits that allows the automated design from the frequency specifications to the building block implementation, applied to the design and synthesis of multistage SC decimators. The compiler provides a library of different topologies that comprises a few independent multi-decimation building blocks. New building blocks defined by the users are also available for the design of a specific stage. A design example of a 7th order SC decimator illustrates the efficient synthesis of the corresponding resulting circuits that achieve the required anti-aliasing amplitude responses with respect to the speed requirements of the operational amplifiers and also the minimum capacitance spread and total capacitor area.

Structural snapshots of the rearrangement of the bis(di-tert-butyl-aminophenyl)amine pincer ligand in the presence of transition metal ions

2018 ◽  
Vol 47 (33) ◽  
pp. 11303-11307 ◽  
Author(s):  
N. Leconte ◽  
B. Baptiste ◽  
C. Philouze ◽  
F. Thomas
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Pincer Ligand ◽  
Tert Butyl ◽  
Redox Active ◽  
Active Transition

The ligand undergoes N–N and C–N bond formations in the presence of redox-active transition metal ions, in air and coordinating solvents.

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