The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Kana M. Sureshan - One of the best experts on this subject based on the ideXlab platform.
-
Sulfonate Protecting Groups: Synthesis of D‐ and L‐myo‐Inositol‐1,3,4,5‐tetrakisphosphate Precursors by a Novel Silver(I) Oxide‐Mediated O‐Alkylation of 2,4(6)‐Di‐O‐acyl‐6(4)‐O‐Sulfonyl‐myo‐Inositol 1,3,5‐Orthoformate Derivatives Through Intramolecul
European Journal of Organic Chemistry, 2003Co-Authors: Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M. BhadbhadeAbstract:Alkylation of racemic 2,4-di-O-acyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates mediated by silver(I) oxide affords the corresponding racemic 2,4-di-O-alkyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates in good yields. Control experiments suggest that these unusual reactions are due to intramolecular assistance by the Sulfonyl Group. O-Alkylation reactions of myo-inositol 1,3,5-orthoformate derivatives provide a new route for the synthesis of important ether derivatives of myo-inositol, which are intermediates for the preparation of phosphoinositols. The utility of this method is demonstrated by the preparation of D- and L-2,4-di-O-benzyl-myo-inositols, which were obtained by benzylation of 2,4-di-O-benzoyl-6-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate and 2,6-di-O-benzoyl-4-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
-
sulfonate protecting Groups synthesis of d and l myo inositol 1 3 4 5 tetrakisphosphate precursors by a novel silver i oxide mediated o alkylation of 2 4 6 di o acyl 6 4 o Sulfonyl myo inositol 1 3 5 orthoformate derivatives through intramolecular as
European Journal of Organic Chemistry, 2003Co-Authors: Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M. BhadbhadeAbstract:Alkylation of racemic 2,4-di-O-acyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates mediated by silver(I) oxide affords the corresponding racemic 2,4-di-O-alkyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates in good yields. Control experiments suggest that these unusual reactions are due to intramolecular assistance by the Sulfonyl Group. O-Alkylation reactions of myo-inositol 1,3,5-orthoformate derivatives provide a new route for the synthesis of important ether derivatives of myo-inositol, which are intermediates for the preparation of phosphoinositols. The utility of this method is demonstrated by the preparation of D- and L-2,4-di-O-benzyl-myo-inositols, which were obtained by benzylation of 2,4-di-O-benzoyl-6-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate and 2,6-di-O-benzoyl-4-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
-
silver i oxide silver halide mediated alcoholysis of o benzoyl myo inositol 1 3 5 orthoformates intramolecular assistance by the Sulfonyl Group
Journal of The Chemical Society-perkin Transactions 1, 2002Co-Authors: Thoniyot Praveen, Kana M. Sureshan, Mysore S. Shashidhar, Uttamkumar Samanta, Pinak ChakrabartiAbstract:Silver(I) oxide–silver halide mediated alcoholyses of racemic 2,4-di-O-benzoyl-myo-inositol 1,3,5-orthoformate, and its 6-O-methyl and 6-O-Sulfonylated derivatives, under identical conditions have been compared. While only the 4-O-benzoyl Group undergoes solvolysis in the former two, to yield the corresponding 2-O-benzoyl-myo-inositol 1,3,5-orthoformate, both the 4-O- as well as the 2-O-benzoyl Groups undergo solvolysis in the latter, to yield racemic 6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates. These results show that solvolysis of the 2-O-benzoyl Group in sulfonates is a consequence of intramolecular assistance by the Sulfonyl Group. Catalytic efficiency of the silver halides in bringing about solvolysis of the benzoates decreased in the order AgI > AgBr > AgCl. A reaction mechanism involving silver–inositol derivative chelates has been proposed.
-
Silver(I) oxide–silver halide mediated alcoholysis of O-benzoyl-myo-inositol 1,3,5-orthoformates: intramolecular assistance by the Sulfonyl Group
Journal of The Chemical Society-perkin Transactions 1, 2001Co-Authors: Thoniyot Praveen, Kana M. Sureshan, Mysore S. Shashidhar, Uttamkumar Samanta, Pinak ChakrabartiAbstract:Silver(I) oxide–silver halide mediated alcoholyses of racemic 2,4-di-O-benzoyl-myo-inositol 1,3,5-orthoformate, and its 6-O-methyl and 6-O-Sulfonylated derivatives, under identical conditions have been compared. While only the 4-O-benzoyl Group undergoes solvolysis in the former two, to yield the corresponding 2-O-benzoyl-myo-inositol 1,3,5-orthoformate, both the 4-O- as well as the 2-O-benzoyl Groups undergo solvolysis in the latter, to yield racemic 6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates. These results show that solvolysis of the 2-O-benzoyl Group in sulfonates is a consequence of intramolecular assistance by the Sulfonyl Group. Catalytic efficiency of the silver halides in bringing about solvolysis of the benzoates decreased in the order AgI > AgBr > AgCl. A reaction mechanism involving silver–inositol derivative chelates has been proposed.
Mohan M. Bhadbhade - One of the best experts on this subject based on the ideXlab platform.
-
Sulfonate Protecting Groups: Synthesis of D‐ and L‐myo‐Inositol‐1,3,4,5‐tetrakisphosphate Precursors by a Novel Silver(I) Oxide‐Mediated O‐Alkylation of 2,4(6)‐Di‐O‐acyl‐6(4)‐O‐Sulfonyl‐myo‐Inositol 1,3,5‐Orthoformate Derivatives Through Intramolecul
European Journal of Organic Chemistry, 2003Co-Authors: Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M. BhadbhadeAbstract:Alkylation of racemic 2,4-di-O-acyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates mediated by silver(I) oxide affords the corresponding racemic 2,4-di-O-alkyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates in good yields. Control experiments suggest that these unusual reactions are due to intramolecular assistance by the Sulfonyl Group. O-Alkylation reactions of myo-inositol 1,3,5-orthoformate derivatives provide a new route for the synthesis of important ether derivatives of myo-inositol, which are intermediates for the preparation of phosphoinositols. The utility of this method is demonstrated by the preparation of D- and L-2,4-di-O-benzyl-myo-inositols, which were obtained by benzylation of 2,4-di-O-benzoyl-6-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate and 2,6-di-O-benzoyl-4-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
-
sulfonate protecting Groups synthesis of d and l myo inositol 1 3 4 5 tetrakisphosphate precursors by a novel silver i oxide mediated o alkylation of 2 4 6 di o acyl 6 4 o Sulfonyl myo inositol 1 3 5 orthoformate derivatives through intramolecular as
European Journal of Organic Chemistry, 2003Co-Authors: Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M. BhadbhadeAbstract:Alkylation of racemic 2,4-di-O-acyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates mediated by silver(I) oxide affords the corresponding racemic 2,4-di-O-alkyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates in good yields. Control experiments suggest that these unusual reactions are due to intramolecular assistance by the Sulfonyl Group. O-Alkylation reactions of myo-inositol 1,3,5-orthoformate derivatives provide a new route for the synthesis of important ether derivatives of myo-inositol, which are intermediates for the preparation of phosphoinositols. The utility of this method is demonstrated by the preparation of D- and L-2,4-di-O-benzyl-myo-inositols, which were obtained by benzylation of 2,4-di-O-benzoyl-6-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate and 2,6-di-O-benzoyl-4-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Juan C Carretero - One of the best experts on this subject based on the ideXlab platform.
-
pdii catalyzed di o olefination of carbazoles directed by the protecting n 2 pyridyl Sulfonyl Group
ChemInform, 2013Co-Authors: Beatriz Urones, Ramon Gomez Arrayas, Juan C CarreteroAbstract:The ability of the N-(2-pyridyl)Sulfonyl Group to serve both as directing and readily removable protecting Group in the Pd(II)-catalyzed regioselective diolefination of carbazoles and structurally related N-heterocycles is demonstrated for the first time.
-
PdII‐Catalyzed Di‐o‐olefination of Carbazoles Directed by the Protecting N‐(2‐Pyridyl)Sulfonyl Group.
ChemInform, 2013Co-Authors: Beatriz Urones, Ramon Gomez Arrayas, Juan C CarreteroAbstract:The ability of the N-(2-pyridyl)Sulfonyl Group to serve both as directing and readily removable protecting Group in the Pd(II)-catalyzed regioselective diolefination of carbazoles and structurally related N-heterocycles is demonstrated for the first time.
-
pdii catalyzed di o olefination of carbazoles directed by the protecting n 2 pyridyl Sulfonyl Group
Organic Letters, 2013Co-Authors: Beatriz Urones, Ramon Gomez Arrayas, Juan C CarreteroAbstract:Despite the significance of carbazole in pharmacy and material science, examples of the direct C–H functionalization of this privileged unit are quite rare. The N-(2-pyridyl)Sulfonyl Group enables the PdII-catalyzed ortho-olefination of carbazoles and related systems, acting as both a directing and readily removable protecting Group. This method features ample structural versatility, affording typically the double ortho-olefination products (at C1 and C8) in satisfactory yields and complete regiocontrol. The application of this procedure to related heterocyclic systems, such as indoline, is also described.
-
pdii catalysed c h functionalisation of indoles and pyrroles assisted by the removable n 2 pyridyl Sulfonyl Group c2 alkenylation and dehydrogenative homocoupling
Chemistry: A European Journal, 2010Co-Authors: Alfonso Garciarubia, Beatriz Urones, Ramon Gomez Arrayas, Juan C CarreteroAbstract:: The easily installed and removed N-(2-pyridyl)Sulfonyl Group exerts complete C2 regiocontrol over the Pd(II)-catalysed C-H alkenylation of indoles and pyrroles, affording the corresponding products in good isolated yields (typically > or = 70 %). A remarkable feature of this catalyst system is that it tolerates a wide variety of substituted alkenes, including conjugated electron-deficient alkenes, styrenes and 1,3-dienes, as well as conjugated 1,1- and 1,2-disubstituted olefins. The final reductive deSulfonylation affords the C2-substituted, free-NH indoles and pyrroles in good yield. This N-(2-pyridyl)Sulfonyl-directing strategy has also been extended to the development of a protocol for the intermolecular, dehydrogenative homocoupling of indoles, providing 2,2'-biindoles. Mechanistic work based upon reactions with isotopically labelled starting materials and competitive kinetic studies of electronically varied substrates suggests a chelation-assisted electrophilic aromatic substitution palladation mechanism.
-
PdII‐Catalysed C ? H Functionalisation of Indoles and Pyrroles Assisted by the Removable N‐(2‐Pyridyl)Sulfonyl Group: C2‐Alkenylation and Dehydrogenative Homocoupling
Chemistry: A European Journal, 2010Co-Authors: Alfonso Garcia‐rubia, Beatriz Urones, Ramon Gomez Arrayas, Juan C CarreteroAbstract:: The easily installed and removed N-(2-pyridyl)Sulfonyl Group exerts complete C2 regiocontrol over the Pd(II)-catalysed C-H alkenylation of indoles and pyrroles, affording the corresponding products in good isolated yields (typically > or = 70 %). A remarkable feature of this catalyst system is that it tolerates a wide variety of substituted alkenes, including conjugated electron-deficient alkenes, styrenes and 1,3-dienes, as well as conjugated 1,1- and 1,2-disubstituted olefins. The final reductive deSulfonylation affords the C2-substituted, free-NH indoles and pyrroles in good yield. This N-(2-pyridyl)Sulfonyl-directing strategy has also been extended to the development of a protocol for the intermolecular, dehydrogenative homocoupling of indoles, providing 2,2'-biindoles. Mechanistic work based upon reactions with isotopically labelled starting materials and competitive kinetic studies of electronically varied substrates suggests a chelation-assisted electrophilic aromatic substitution palladation mechanism.
Mysore S. Shashidhar - One of the best experts on this subject based on the ideXlab platform.
-
Sulfonate Protecting Groups: Synthesis of D‐ and L‐myo‐Inositol‐1,3,4,5‐tetrakisphosphate Precursors by a Novel Silver(I) Oxide‐Mediated O‐Alkylation of 2,4(6)‐Di‐O‐acyl‐6(4)‐O‐Sulfonyl‐myo‐Inositol 1,3,5‐Orthoformate Derivatives Through Intramolecul
European Journal of Organic Chemistry, 2003Co-Authors: Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M. BhadbhadeAbstract:Alkylation of racemic 2,4-di-O-acyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates mediated by silver(I) oxide affords the corresponding racemic 2,4-di-O-alkyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates in good yields. Control experiments suggest that these unusual reactions are due to intramolecular assistance by the Sulfonyl Group. O-Alkylation reactions of myo-inositol 1,3,5-orthoformate derivatives provide a new route for the synthesis of important ether derivatives of myo-inositol, which are intermediates for the preparation of phosphoinositols. The utility of this method is demonstrated by the preparation of D- and L-2,4-di-O-benzyl-myo-inositols, which were obtained by benzylation of 2,4-di-O-benzoyl-6-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate and 2,6-di-O-benzoyl-4-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
-
sulfonate protecting Groups synthesis of d and l myo inositol 1 3 4 5 tetrakisphosphate precursors by a novel silver i oxide mediated o alkylation of 2 4 6 di o acyl 6 4 o Sulfonyl myo inositol 1 3 5 orthoformate derivatives through intramolecular as
European Journal of Organic Chemistry, 2003Co-Authors: Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M. BhadbhadeAbstract:Alkylation of racemic 2,4-di-O-acyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates mediated by silver(I) oxide affords the corresponding racemic 2,4-di-O-alkyl-6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates in good yields. Control experiments suggest that these unusual reactions are due to intramolecular assistance by the Sulfonyl Group. O-Alkylation reactions of myo-inositol 1,3,5-orthoformate derivatives provide a new route for the synthesis of important ether derivatives of myo-inositol, which are intermediates for the preparation of phosphoinositols. The utility of this method is demonstrated by the preparation of D- and L-2,4-di-O-benzyl-myo-inositols, which were obtained by benzylation of 2,4-di-O-benzoyl-6-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate and 2,6-di-O-benzoyl-4-O-camphorSulfonyl-myo-inositol 1,3,5-orthoformate. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
-
silver i oxide silver halide mediated alcoholysis of o benzoyl myo inositol 1 3 5 orthoformates intramolecular assistance by the Sulfonyl Group
Journal of The Chemical Society-perkin Transactions 1, 2002Co-Authors: Thoniyot Praveen, Kana M. Sureshan, Mysore S. Shashidhar, Uttamkumar Samanta, Pinak ChakrabartiAbstract:Silver(I) oxide–silver halide mediated alcoholyses of racemic 2,4-di-O-benzoyl-myo-inositol 1,3,5-orthoformate, and its 6-O-methyl and 6-O-Sulfonylated derivatives, under identical conditions have been compared. While only the 4-O-benzoyl Group undergoes solvolysis in the former two, to yield the corresponding 2-O-benzoyl-myo-inositol 1,3,5-orthoformate, both the 4-O- as well as the 2-O-benzoyl Groups undergo solvolysis in the latter, to yield racemic 6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates. These results show that solvolysis of the 2-O-benzoyl Group in sulfonates is a consequence of intramolecular assistance by the Sulfonyl Group. Catalytic efficiency of the silver halides in bringing about solvolysis of the benzoates decreased in the order AgI > AgBr > AgCl. A reaction mechanism involving silver–inositol derivative chelates has been proposed.
-
Silver(I) oxide–silver halide mediated alcoholysis of O-benzoyl-myo-inositol 1,3,5-orthoformates: intramolecular assistance by the Sulfonyl Group
Journal of The Chemical Society-perkin Transactions 1, 2001Co-Authors: Thoniyot Praveen, Kana M. Sureshan, Mysore S. Shashidhar, Uttamkumar Samanta, Pinak ChakrabartiAbstract:Silver(I) oxide–silver halide mediated alcoholyses of racemic 2,4-di-O-benzoyl-myo-inositol 1,3,5-orthoformate, and its 6-O-methyl and 6-O-Sulfonylated derivatives, under identical conditions have been compared. While only the 4-O-benzoyl Group undergoes solvolysis in the former two, to yield the corresponding 2-O-benzoyl-myo-inositol 1,3,5-orthoformate, both the 4-O- as well as the 2-O-benzoyl Groups undergo solvolysis in the latter, to yield racemic 6-O-Sulfonyl-myo-inositol 1,3,5-orthoformates. These results show that solvolysis of the 2-O-benzoyl Group in sulfonates is a consequence of intramolecular assistance by the Sulfonyl Group. Catalytic efficiency of the silver halides in bringing about solvolysis of the benzoates decreased in the order AgI > AgBr > AgCl. A reaction mechanism involving silver–inositol derivative chelates has been proposed.
Daniel Grande - One of the best experts on this subject based on the ideXlab platform.
-
Original route to polylactide–polystyrene diblock copolymers containing a Sulfonyl Group at the junction between both blocks as precursors to functional nanoporous materials
Reactive & Functional Polymers, 2012Co-Authors: Rim Majdoub, Tarek Antoun, Benjamin Le Droumaguet, Mourad Benzina, Daniel GrandeAbstract:Abstract Novel functionalized nanoporous polymeric materials could be derived from poly(D,L-lactide)- block -polystyrene (PLA- b -PS) diblock copolymers with a Sulfonyl Group at the junction between both blocks were synthesized by a combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP) using a synthetic difunctional initiator through a three-step sequential methodology. Different ω-bromo PLA polymers with various molar masses ranging from 3640 to 11,440 g mol −1 were first produced by coupling ω-hydroxy PLA precursors to a chloroSulfonyl-functionalized ATRP initiator previously prepared, thus leading to the formation of suitable macroinitiators for the subsequent ATRP polymerization of styrene. Consequently, PLA- b -PS diblock copolymers were obtained with a finely tuned PLA volume fraction ( f PLA ) in order to develop a microphased-separation morphology. The resulting copolymers as well as the intermediate compounds were carefully analyzed by size exclusion chromatography and 1 H NMR. Upon shear flow induced by a channel die processing, oriented copolymers were generally afforded as characterized by small-angle-X-ray scattering (SAXS). Such copolymers were finally submitted to mild alkaline conditions so as to hydrolyze the sacrificial PLA block, and the presence of the sulfonic acid functionality on the pore walls of the resulting nanoporous materials was evidenced by means of a post-modification reaction consisting in the corresponding sulfonamide formation.
-
original route to polylactide polystyrene diblock copolymers containing a Sulfonyl Group at the junction between both blocks as precursors to functional nanoporous materials
Reactive & Functional Polymers, 2012Co-Authors: Rim Majdoub, Tarek Antoun, Benjamin Le Droumaguet, Mourad Benzina, Daniel GrandeAbstract:Abstract Novel functionalized nanoporous polymeric materials could be derived from poly(D,L-lactide)- block -polystyrene (PLA- b -PS) diblock copolymers with a Sulfonyl Group at the junction between both blocks were synthesized by a combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP) using a synthetic difunctional initiator through a three-step sequential methodology. Different ω-bromo PLA polymers with various molar masses ranging from 3640 to 11,440 g mol −1 were first produced by coupling ω-hydroxy PLA precursors to a chloroSulfonyl-functionalized ATRP initiator previously prepared, thus leading to the formation of suitable macroinitiators for the subsequent ATRP polymerization of styrene. Consequently, PLA- b -PS diblock copolymers were obtained with a finely tuned PLA volume fraction ( f PLA ) in order to develop a microphased-separation morphology. The resulting copolymers as well as the intermediate compounds were carefully analyzed by size exclusion chromatography and 1 H NMR. Upon shear flow induced by a channel die processing, oriented copolymers were generally afforded as characterized by small-angle-X-ray scattering (SAXS). Such copolymers were finally submitted to mild alkaline conditions so as to hydrolyze the sacrificial PLA block, and the presence of the sulfonic acid functionality on the pore walls of the resulting nanoporous materials was evidenced by means of a post-modification reaction consisting in the corresponding sulfonamide formation.
-
Original route to polylactide-polystyrene diblock copolymers containing a Sulfonyl Group at the junction between both blocks as precursors to functional nanoporous materials
Reactive and Functional Polymers, 2012Co-Authors: Rim Majdoub, Tarek Antoun, Benjamin Le Droumaguet, Mourad Benzina, Daniel GrandeAbstract:Novel functionalized nanoporous polymeric materials could be derived from poly(D,L-lactide)-block-polystyrene (PLA-b-PS) diblock copolymers with a Sulfonyl Group at the junction between both blocks were synthesized by a combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP) using a synthetic difunctional initiator through a three-step sequential methodology. Different ω-bromo PLA polymers with various molar masses ranging from 3640 to 11,440 g mol -1 were first produced by coupling ω-hydroxy PLA precursors to a chloroSulfonyl- functionalized ATRP initiator previously prepared, thus leading to the formation of suitable macroinitiators for the subsequent ATRP polymerization of styrene. Consequently, PLA-b-PS diblock copolymers were obtained with a finely tuned PLA volume fraction (f PLA ) in order to develop a microphased-separation morphology. The resulting copolymers as well as the intermediate compounds were carefully analyzed by size exclusion chromatography and 1 H NMR. Upon shear flow induced by a channel die processing, oriented copolymers were generally afforded as characterized by small-angle-X-ray scattering (SAXS). Such copolymers were finally submitted to mild alkaline conditions so as to hydrolyze the sacrificial PLA block, and the presence of the sulfonic acid functionality on the pore walls of the resulting nanoporous materials was evidenced by means of a post-modification reaction consisting in the corresponding sulfonamide formation. © 2012 Elsevier Ltd. All rights reserved.
