scholarly journals Pauson–Khand reaction of fluorinated compounds

2020 ◽  
Vol 16 ◽  
pp. 1662-1682 ◽  
Author(s):  
Jorge Escorihuela ◽  
Daniel M Sedgwick ◽  
Alberto Llobat ◽  
Mercedes Medio-Simón ◽  
Pablo Barrio ◽  
...  

The Pauson–Khand reaction (PKR) is one of the key methods for the construction of cyclopentenone derivatives, which can in turn undergo diverse chemical transformations to yield more complex biologically active molecules. Despite the increasing availability of fluorinated building blocks and methodologies to incorporate fluorine in compounds with biological interest, there have been few significant advances focused on the fluoro-Pauson–Khand reaction, both in the inter- and intramolecular versions. Furthermore, the use of vinyl fluorides as olefinic counterparts had been completely overlooked. In this review, we collect the advances both on the stoichiometric and catalytic intermolecular and intramolecular fluoro-Pauson–Khand reaction, with special attention to the PKR of enynes containing a fluoride moiety.

Synlett ◽  
2020 ◽  
Author(s):  
Erica Benedetti ◽  
Laurent Micouin ◽  
Claire Fleurisson

AbstractCyclic cis-1,3-diamines are versatile building blocks frequently found in natural molecules or biologically active compounds. In comparison with widely studied 1,2-diamines, and despite their chemical similarity, 1,3-diamines have been investigated less intensively probably because of a lack of general synthetic procedures giving access to these compounds with good levels of chemo-, regio-, and stereocontrol. In this Account we will give a general overview of the biological interest of cyclic cis-1,3-diamines. We will then describe the synthesis and potential applications of these compounds with a particular focus on the work realized in our laboratory.1 Introduction2 Biological Relevance of the cis-1,3-Diamine Motif3 Classical Synthetic Strategies towards cis-1,3-Diamines4 N–N Bond Cleavage of Bicyclic Hydrazines: A Versatile Method to Access cis-1,3-Diamines4.1 Preparation of Five-Membered Cyclic cis-1,3-Diamino Alcohols4.2 Access to Fluorinated 1,3-cis-Diaminocyclopentanes4.3 Synthesis of cis-1,3-Diaminocyclohexitols4.4 Formation of Cyclic cis-3,5-Diaminopiperidines5 Applications of Cyclic cis-1,3-Diamines5.1 Small-Molecular RNA Binders5.2 Fluorinated 1,3-Diamino Cyclopentanes as NMR Probes6 Concluding Remarks


Química Nova ◽  
2021 ◽  
Author(s):  
Dartagnan Ferreira ◽  
Valter Murie ◽  
Thiago Santos ◽  
Paulo Vieira ◽  
Giuliano Clososki

RECENT ADVANCES IN SELECTIVE FUNCTIONALIZATION OF QUINOLINES. Heterocyclic compounds form an important and extensive group of organic substances. Among nitrogenous heterocyclic molecules, quinolines stand out for exhibiting attractive chemical and biological properties. These substances can be used as ligands, sensors, luminescent and agrochemical materials. In addition, quinoline-containing compounds can exhibit a wide spectrum of pharmacological properties, allowing their use in several approved drugs nowadays. Due to its importance, the synthesis of molecules containing this nucleus becomes a point of interest for synthetic chemists. In this way, several methodologies have been recently developed to prepare quinoline derivatives with high structural diversity. Such chemical transformations allow the chemical modification of these rings with high selectivity and tolerance to diverse functional groups and these properties have been conveniently used in the preparation of biologically active molecules containing this unit. Herein, we present a review of the main methodologies employed in the selective functionalization of quinolines in the last twenty years. In this context, a brief introduction addressing general synthetic and medicinal aspects related to the functionalization positions of the quinoline ring is presented. Several methodologies used in the functionalization of this moiety are discussed, as well relevant synthetic applications, both in the preparation and functionalization of substances of biological interest.


Author(s):  
Vijey Aanandhi M ◽  
Ravichandiran V ◽  
Prem Shankar Misra

Objective: 2-pyridone is a well-known heterocyclic ring having significant biological and medical application. The molecular structures and various activities of 2-pyridone derivatives as well as their syntheses and natural occurrence are analyzed and reviewed, and their reactivity toward various nucleophiles is discussed.Methods: 2-pyridone derivatives, first naturally obtained and described as early as before the 19th century, have been attracting increasing attention in view of their high reactivity as building blocks for the preparation of compounds of various classes due to their selective transformations with different reagents. Much information describing the natural occurrence, synthesis and the significant biological activity of 2-pyridone compounds are scattered throughout the literature. There are short chapters dealing with the synthesis and activity of 2-pyridone derivatives.Results: After compiling the above material, the abundance of certain heterocyclic ring and nature of typical chemical transformations applied in current drug synthesis. It is likely this results from the abundance of these heterocycles in natural products such as alkaloids and various synthetic derivatives revealing different biological activity. This might suggest a classical approach to drug design where substrate analogs gain inspiration from existing natural ligands.Conclusions: The data considered in this review clearly demonstrate the high synthetic potential of 2-pyridone derivatives. Many biologically active heterocyclic compounds have been obtained based on this heterocyclic ring. This suggests that 2-pyridone can be used in the design of novel highly effective pharmaceuticals with a broad spectrum of bioresponses.


2019 ◽  
Author(s):  
Jiajing Bao ◽  
Hailong Tian ◽  
Peicheng Yang ◽  
Jiachen Deng ◽  
Jinghan Gui

The development of new chemical transformations to simplify the synthesis of valuable building blocks is a challenging task in organic chemistry and has been the focus of considerable research effort. From a synthetic perspective, it would be ideal if the natural reactivities of feedstock chemicals could be diverted to the production of high value-added compounds which are otherwise tedious to prepare. Here we report a chemical transformation that enables facile and modular synthesis of synthetically challenging yet biologically important functionalized butenolides from easily accessible furans. Specifically, Diels–Alder reactions between furans and singlet oxygen generate versatile hydroperoxide intermediates, which undergo iron(II)-mediated radical fragmentation in the presence of Cu(OAc)<sub>2</sub> or various radical trapping reagents to afford butenolides bearing a wide variety of appended remote functional groups, including olefins, halides, azides and aldehydes. The practical utility of this transformation is demonstrated by easy diversification of the products by means of cross-coupling reactions and, most importantly, by its ability to simplify the syntheses of known building blocks of eight biologically active natural products.


2019 ◽  
Author(s):  
Jiajing Bao ◽  
Hailong Tian ◽  
Peicheng Yang ◽  
Jiachen Deng ◽  
Jinghan Gui

The development of new chemical transformations to simplify the synthesis of valuable building blocks is a challenging task in organic chemistry and has been the focus of considerable research effort. From a synthetic perspective, it would be ideal if the natural reactivities of feedstock chemicals could be diverted to the production of high value-added compounds which are otherwise tedious to prepare. Here we report a chemical transformation that enables facile and modular synthesis of synthetically challenging yet biologically important functionalized butenolides from easily accessible furans. Specifically, Diels–Alder reactions between furans and singlet oxygen generate versatile hydroperoxide intermediates, which undergo iron(II)-mediated radical fragmentation in the presence of Cu(OAc)<sub>2</sub> or various radical trapping reagents to afford butenolides bearing a wide variety of appended remote functional groups, including olefins, halides, azides and aldehydes. The practical utility of this transformation is demonstrated by easy diversification of the products by means of cross-coupling reactions and, most importantly, by its ability to simplify the syntheses of known building blocks of eight biologically active natural products.


2020 ◽  
Author(s):  
Rui Guo ◽  
Xiaotian Qi ◽  
Hengye Xiang ◽  
Paul Geaneoates ◽  
Ruihan Wang ◽  
...  

Vinyl fluorides play an important role in drug development as they serve as bioisosteres for peptide bonds and are found in a range of biologically active molecules. The discovery of safe, general and practical procedures to prepare vinyl fluorides remains an important goal and challenge for synthetic chemistry. Here we introduce an inexpensive and easily-handled reagent and report simple, scalable, and metal-free protocols for the regioselective and stereodivergent hydrofluorination of alkynes to access both the E and Z isomers of vinyl fluorides. These conditions were suitable for a diverse collection of alkynes, including several highly-functionalized pharmaceutical derivatives. Mechanistic and DFT studies support C–F bond formation through a vinyl cation intermediate, with the (E)- and (Z)-hydrofluorination products forming under kinetic and thermodynamic control, respectively.<br>


2013 ◽  
Vol 85 (8) ◽  
pp. 1683-1692 ◽  
Author(s):  
Valeria Corne ◽  
María Celeste Botta ◽  
Enrique D. V. Giordano ◽  
Germán F. Giri ◽  
David F. Llompart ◽  
...  

Modern organic chemistry requires easily obtainable chiral building blocks that show high chemical versatility for their application in the synthesis of enantiopure compounds. Biomass has been demonstrated to be a widely available raw material that represents the only abundant source of renewable organic carbon. Through the pyrolitic conversion of cellulose or cellulose-containing materials it is possible to produce levoglucosenone, a highly functionalized chiral structure. This compound has been innovatively used as a template for the synthesis of key intermediates of biologically active products and for the preparation of chiral auxiliaries, catalysts, and organocatalysts for their application in asymmetric synthesis.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Patricia Calero ◽  
Daniel C. Volke ◽  
Phillip T. Lowe ◽  
Charlotte H. Gotfredsen ◽  
David O’Hagan ◽  
...  

Abstract Fluorine is a key element in the synthesis of molecules broadly used in medicine, agriculture and materials. Addition of fluorine to organic structures represents a unique strategy for tuning molecular properties, yet this atom is rarely found in Nature and approaches to integrate fluorometabolites into the biochemistry of living cells are scarce. In this work, synthetic gene circuits for organofluorine biosynthesis are implemented in the platform bacterium Pseudomonas putida. By harnessing fluoride-responsive riboswitches and the orthogonal T7 RNA polymerase, biochemical reactions needed for in vivo biofluorination are wired to the presence of fluoride (i.e. circumventing the need of feeding expensive additives). Biosynthesis of fluoronucleotides and fluorosugars in engineered P. putida is demonstrated with mineral fluoride both as only fluorine source (i.e. substrate of the pathway) and as inducer of the synthetic circuit. This approach expands the chemical landscape of cell factories by providing alternative biosynthetic strategies towards fluorinated building-blocks.


2019 ◽  
Vol 91 (5) ◽  
pp. 811-838 ◽  
Author(s):  
Marian Mikołajczyk

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.


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