The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
David J Procter - One of the best experts on this subject based on the ideXlab platform.
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Para-coupling of phenols with C2/C3-substituted benzothiophene S-oxides
Tetrahedron, 2020Co-Authors: Zhen He, Gregory J P Perry, Tony Biremond, David J ProcterAbstract:Abstract C2 and C3 substituted Benzothiophenes are common structures in medicinal and materials chemistry. The cross-coupling of phenols with Benzothiophenes is a useful route towards these important molecules. In this report we reveal an efficient C–H/C–H-type cross-coupling of Benzothiophenes, activated as their S-oxides, with phenols to give C2/C3 arylated Benzothiophenes. Whereas previous reports describe cross-coupling at the ortho-position between phenols and sulfoxides, this procedure allows para-functionalization of phenols that typically have their ortho positions blocked.
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metal free synthesis of Benzothiophenes by twofold c h functionalization direct access to materials oriented heteroaromatics
Angewandte Chemie, 2019Co-Authors: Alexander P Pulis, Gregory J P Perry, David J ProcterAbstract:: Due to their ubiquity in nature and frequent use in organic electronic materials, Benzothiophenes are highly sought after. Here we set out an unprecedented procedure for the formation of Benzothiophenes by the twofold vicinal C-H functionalization of arenes that does not require metal catalysis. This one-pot annulation proceeds through an interrupted Pummerer reaction/[3,3]-sigmatropic rearrangement/cyclization sequence to deliver various benzothiophene products. The procedure is particularly effective for the rapid synthesis of Benzothiophenes from non-prefunctionalized polyaromatic hydrocarbons (PAHs).
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transition metal free cross coupling of Benzothiophenes and styrenes in a stereoselective synthesis of substituted e z 1 3 dienes
Angewandte Chemie, 2019Co-Authors: Mindaugas Siauciulis, Alexander P Pulis, Nanna Ahlsten, David J ProcterAbstract:: A transition metal-free one-pot stereoselective approach to substituted (E,Z)-1,3-dienes was developed by using an interrupted Pummerer reaction/ligand-coupling strategy. Readily available benzothiophene S-oxides, which can be conveniently prepared by oxidation of the parent Benzothiophenes, undergo Pummerer coupling with styrenes. Reaction of the resultant sulfonium salts with alkyllithium/magnesium reagents generates underexploited hypervalent sulfurane intermediates that undergo selective ligand coupling, resulting in dismantling of the benzothiophene motif and the formation of decorated (E,Z)-1,3-dienes.
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pummerer chemistry of benzothiophene s oxides metal free alkylation and arylation of Benzothiophenes
Phosphorus Sulfur and Silicon and The Related Elements, 2019Co-Authors: Zhen He, Alexander P Pulis, Gregory J P Perry, David J ProcterAbstract:AbstractFunctionalized Benzothiophenes are important constructs found in molecules with wide ranging biological activity and in organic materials. An efficient, metal-free approach to C3 and C2 ary...
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transition metal free synthesis of c3 arylated benzofurans from Benzothiophenes and phenols
Organic Letters, 2018Co-Authors: Kevin Yang, Alexander P Pulis, Gregory J P Perry, David J ProcterAbstract:We report a transition-metal-free synthesis of benzofurans from Benzothiophenes and phenols that exploits the unique reactivity of sulfoxides. Through a sequence involving an interrupted Pummerer reaction and [3,3] sigmatropic rearrangement, phenols can be combined with readily accessible yet synthetically unexplored benzothiophene S-oxides to provide C3-arylated benzofuran products. The products from this approach can undergo subsequent functionalization to gain access to a range of important benzofuran derivatives.
Alexander P Pulis - One of the best experts on this subject based on the ideXlab platform.
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metal free synthesis of Benzothiophenes by twofold c h functionalization direct access to materials oriented heteroaromatics
Angewandte Chemie, 2019Co-Authors: Alexander P Pulis, Gregory J P Perry, David J ProcterAbstract:: Due to their ubiquity in nature and frequent use in organic electronic materials, Benzothiophenes are highly sought after. Here we set out an unprecedented procedure for the formation of Benzothiophenes by the twofold vicinal C-H functionalization of arenes that does not require metal catalysis. This one-pot annulation proceeds through an interrupted Pummerer reaction/[3,3]-sigmatropic rearrangement/cyclization sequence to deliver various benzothiophene products. The procedure is particularly effective for the rapid synthesis of Benzothiophenes from non-prefunctionalized polyaromatic hydrocarbons (PAHs).
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transition metal free cross coupling of Benzothiophenes and styrenes in a stereoselective synthesis of substituted e z 1 3 dienes
Angewandte Chemie, 2019Co-Authors: Mindaugas Siauciulis, Alexander P Pulis, Nanna Ahlsten, David J ProcterAbstract:: A transition metal-free one-pot stereoselective approach to substituted (E,Z)-1,3-dienes was developed by using an interrupted Pummerer reaction/ligand-coupling strategy. Readily available benzothiophene S-oxides, which can be conveniently prepared by oxidation of the parent Benzothiophenes, undergo Pummerer coupling with styrenes. Reaction of the resultant sulfonium salts with alkyllithium/magnesium reagents generates underexploited hypervalent sulfurane intermediates that undergo selective ligand coupling, resulting in dismantling of the benzothiophene motif and the formation of decorated (E,Z)-1,3-dienes.
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pummerer chemistry of benzothiophene s oxides metal free alkylation and arylation of Benzothiophenes
Phosphorus Sulfur and Silicon and The Related Elements, 2019Co-Authors: Zhen He, Alexander P Pulis, Gregory J P Perry, David J ProcterAbstract:AbstractFunctionalized Benzothiophenes are important constructs found in molecules with wide ranging biological activity and in organic materials. An efficient, metal-free approach to C3 and C2 ary...
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transition metal free synthesis of c3 arylated benzofurans from Benzothiophenes and phenols
Organic Letters, 2018Co-Authors: Kevin Yang, Alexander P Pulis, Gregory J P Perry, David J ProcterAbstract:We report a transition-metal-free synthesis of benzofurans from Benzothiophenes and phenols that exploits the unique reactivity of sulfoxides. Through a sequence involving an interrupted Pummerer reaction and [3,3] sigmatropic rearrangement, phenols can be combined with readily accessible yet synthetically unexplored benzothiophene S-oxides to provide C3-arylated benzofuran products. The products from this approach can undergo subsequent functionalization to gain access to a range of important benzofuran derivatives.
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synthesis of c2 substituted Benzothiophenes via an interrupted pummerer 3 3 sigmatropic 1 2 migration cascade of benzothiophene s oxides
Angewandte Chemie, 2018Co-Authors: Zhen He, Harry J Shrives, Jose A Fernandezsalas, Alberto Abengozar, Jessica Neufeld, Kevin Yang, Alexander P Pulis, David J ProcterAbstract:: Functionalized Benzothiophenes are important scaffolds found in molecules with wide ranging biological activity and in organic materials. We describe an efficient, metal-free synthesis of C2 arylated, allylated, and propargylated Benzothiophenes. The reaction utilizes synthetically unexplored yet readily accessible benzothiophene S-oxides and phenols, allyl-, or propargyl silanes in a unique cascade sequence. An interrupted Pummerer reaction between benzothiophene S-oxides and the coupling partners yields sulfonium salts that lack aromaticity and therefore allow facile [3,3]-sigmatropic rearrangement. The subsequently generated benzothiophenium salts undergo a previously unexplored 1,2-migration to access C2 functionalized Benzothiophenes.
Kevin Yang - One of the best experts on this subject based on the ideXlab platform.
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transition metal free synthesis of c3 arylated benzofurans from Benzothiophenes and phenols
Organic Letters, 2018Co-Authors: Kevin Yang, Alexander P Pulis, Gregory J P Perry, David J ProcterAbstract:We report a transition-metal-free synthesis of benzofurans from Benzothiophenes and phenols that exploits the unique reactivity of sulfoxides. Through a sequence involving an interrupted Pummerer reaction and [3,3] sigmatropic rearrangement, phenols can be combined with readily accessible yet synthetically unexplored benzothiophene S-oxides to provide C3-arylated benzofuran products. The products from this approach can undergo subsequent functionalization to gain access to a range of important benzofuran derivatives.
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synthesis of c2 substituted Benzothiophenes via an interrupted pummerer 3 3 sigmatropic 1 2 migration cascade of benzothiophene s oxides
Angewandte Chemie, 2018Co-Authors: Zhen He, Harry J Shrives, Jose A Fernandezsalas, Alberto Abengozar, Jessica Neufeld, Kevin Yang, Alexander P Pulis, David J ProcterAbstract:: Functionalized Benzothiophenes are important scaffolds found in molecules with wide ranging biological activity and in organic materials. We describe an efficient, metal-free synthesis of C2 arylated, allylated, and propargylated Benzothiophenes. The reaction utilizes synthetically unexplored yet readily accessible benzothiophene S-oxides and phenols, allyl-, or propargyl silanes in a unique cascade sequence. An interrupted Pummerer reaction between benzothiophene S-oxides and the coupling partners yields sulfonium salts that lack aromaticity and therefore allow facile [3,3]-sigmatropic rearrangement. The subsequently generated benzothiophenium salts undergo a previously unexplored 1,2-migration to access C2 functionalized Benzothiophenes.
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Synthesis of C2 Substituted Benzothiophenes via an Interrupted Pummerer/[3,3]-Sigmatropic/1,2-Migration Cascade of Benzothiophene S-Oxides.
Angewandte Chemie, 2018Co-Authors: Zhen He, Harry J Shrives, Alberto Abengozar, Jessica Neufeld, Kevin Yang, Alexander P Pulis, José A. Fernández-salas, David J ProcterAbstract:: Functionalized Benzothiophenes are important scaffolds found in molecules with wide ranging biological activity and in organic materials. We describe an efficient, metal-free synthesis of C2 arylated, allylated, and propargylated Benzothiophenes. The reaction utilizes synthetically unexplored yet readily accessible benzothiophene S-oxides and phenols, allyl-, or propargyl silanes in a unique cascade sequence. An interrupted Pummerer reaction between benzothiophene S-oxides and the coupling partners yields sulfonium salts that lack aromaticity and therefore allow facile [3,3]-sigmatropic rearrangement. The subsequently generated benzothiophenium salts undergo a previously unexplored 1,2-migration to access C2 functionalized Benzothiophenes.
Harry J Shrives - One of the best experts on this subject based on the ideXlab platform.
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synthesis of c2 substituted Benzothiophenes via an interrupted pummerer 3 3 sigmatropic 1 2 migration cascade of benzothiophene s oxides
Angewandte Chemie, 2018Co-Authors: Zhen He, Harry J Shrives, Jose A Fernandezsalas, Alberto Abengozar, Jessica Neufeld, Kevin Yang, Alexander P Pulis, David J ProcterAbstract:: Functionalized Benzothiophenes are important scaffolds found in molecules with wide ranging biological activity and in organic materials. We describe an efficient, metal-free synthesis of C2 arylated, allylated, and propargylated Benzothiophenes. The reaction utilizes synthetically unexplored yet readily accessible benzothiophene S-oxides and phenols, allyl-, or propargyl silanes in a unique cascade sequence. An interrupted Pummerer reaction between benzothiophene S-oxides and the coupling partners yields sulfonium salts that lack aromaticity and therefore allow facile [3,3]-sigmatropic rearrangement. The subsequently generated benzothiophenium salts undergo a previously unexplored 1,2-migration to access C2 functionalized Benzothiophenes.
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Synthesis of C2 Substituted Benzothiophenes via an Interrupted Pummerer/[3,3]-Sigmatropic/1,2-Migration Cascade of Benzothiophene S-Oxides.
Angewandte Chemie, 2018Co-Authors: Zhen He, Harry J Shrives, Alberto Abengozar, Jessica Neufeld, Kevin Yang, Alexander P Pulis, José A. Fernández-salas, David J ProcterAbstract:: Functionalized Benzothiophenes are important scaffolds found in molecules with wide ranging biological activity and in organic materials. We describe an efficient, metal-free synthesis of C2 arylated, allylated, and propargylated Benzothiophenes. The reaction utilizes synthetically unexplored yet readily accessible benzothiophene S-oxides and phenols, allyl-, or propargyl silanes in a unique cascade sequence. An interrupted Pummerer reaction between benzothiophene S-oxides and the coupling partners yields sulfonium salts that lack aromaticity and therefore allow facile [3,3]-sigmatropic rearrangement. The subsequently generated benzothiophenium salts undergo a previously unexplored 1,2-migration to access C2 functionalized Benzothiophenes.
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regioselective synthesis of c3 alkylated and arylated Benzothiophenes
Nature Communications, 2017Co-Authors: Harry J Shrives, Jose A Fernandezsalas, Alexander P Pulis, Christin Hedtke, David J ProcterAbstract:Benzothiophenes are heterocyclic constituents of important molecules relevant to society, including those with the potential to meet modern medical challenges. The construction of molecules would be vastly more efficient if carbon–hydrogen bonds, found in all organic molecules, can be directly converted into carbon–carbon bonds. In the case of elaborating Benzothiophenes, functionalization of carbon–hydrogen bonds at carbon-number 3 (C3) is markedly more demanding than at C2 due to issues of regioselectivity (C3 versus C2), and the requirement of high temperatures, precious metals and the installation of superfluous directing groups. Herein, we demonstrate that synthetically unexplored but readily accessible benzothiophene S-oxides serve as novel precursors for C3-functionalized Benzothiophenes. Employing an interrupted Pummerer reaction to capture and then deliver phenol and silane coupling partners, we have discovered a directing group-free method that delivers C3-arylated and -alkylated Benzothiophenes with complete regioselectivity, under metal-free and mild conditions. Benzothiophenes are common motifs in bioactive compounds, but selective functionalization at C3 is challenging. Here the authors report a method starting from benzothiophene S-oxides via an interrupted Pummerer reaction, giving access to a range of C3-alkylated and -arylated products.
Murray R. Gray - One of the best experts on this subject based on the ideXlab platform.
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Sulfur from benzothiophene and alkylBenzothiophenes supports growth of Rhodococcus sp. strain JVH1
Biodegradation, 2007Co-Authors: Kathlyn M. Kirkwood, Jan T. Andersson, Phillip M. Fedorak, Julia M. Foght, Murray R. GrayAbstract:Rhodococcus sp. strain JVH1 was previously reported to use a number of compounds with aliphatic sulfide bridges as sulfur sources for growth. We have shown that although JVH1 does not use the three-ring thiophenic sulfur compound dibenzothiophene, this strain can use the two-ring compound benzothiophene as its sole sulfur source, resulting in growth of the culture and loss of benzothiophene. Addition of inorganic sulfate to the medium reduced the conversion of benzothiophene, indicating that benzothiophene metabolism is repressed by sulfate and that benzothiophene is therefore used specifically as a sulfur source. JVH1 also used all six isomers of methylbenzothiophene and two dimethylbenzothiophene isomers as sulfur sources for growth. Metabolites identified from benzothiophene and some methylBenzothiophenes were consistent with published pathways for benzothiophene biodesulfurization. Products retaining the sulfur atom were sulfones and sultines, the sultines being formed from phenolic sulfinates under acidic extraction conditions. With 2-methylbenzothiophene, the final desulfurized product was 2-methylbenzofuran, formed by dehydration of 3-( o -hydroxyphenyl) propanone under acidic extraction conditions and indicating an oxygenative desulfination reaction. With 3-methylbenzothiophene, the final desulfurized product was 2-isopropenylphenol, indicating a hydrolytic desulfination reaction. JVH1 is the first microorganism reported to use all six isomers of methylbenzothiophene, as well as some dimethylbenzothiophene isomers, as sole sulfur sources. JVH1 therefore possesses broader sulfur extraction abilities than previously reported, including not only sulfidic compounds but also some thiophenic species.
