The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Stefan Bräse - One of the best experts on this subject based on the ideXlab platform.
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synthesis of new Diketopiperazines thiolation to thioDiketopiperazines and examination of their ros generating properties
European Journal of Organic Chemistry, 2015Co-Authors: Sabilla Zhong, Martin Nieger, Angela E. E. Wandler, Ute Schepers, Stefan BräseAbstract:A variety of new symmetrical and unsymmetrical Diketopiperazines have been prepared from free amino acids by using a previously developed microwave-assisted protocol. This included the successful incorporation of L-pyroglutamic acid as an unusual building block. The Diketopiperazines were then thiolated electrophilically to the corresponding bis(methylthio)- and epidithioDiketopiperazines. Initial experiments showed a promising activity towards the generation of reactive oxygen species in HeLa cells.
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Synthesis of New Diketopiperazines, Thiolation to ThioDiketopiperazines, and Examination of Their ROS‐Generating Properties
European Journal of Organic Chemistry, 2015Co-Authors: Sabilla Zhong, Martin Nieger, Angela E. E. Wandler, Ute Schepers, Stefan BräseAbstract:A variety of new symmetrical and unsymmetrical Diketopiperazines have been prepared from free amino acids by using a previously developed microwave-assisted protocol. This included the successful incorporation of L-pyroglutamic acid as an unusual building block. The Diketopiperazines were then thiolated electrophilically to the corresponding bis(methylthio)- and epidithioDiketopiperazines. Initial experiments showed a promising activity towards the generation of reactive oxygen species in HeLa cells.
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One-Pot Synthesis of Symmetrical and Unsymmetrical Diketopiperazines from Unprotected Amino Acids
Synlett, 2007Co-Authors: Anne Friedrich, Manuel Jainta, Martin Nieger, Stefan BräseAbstract:An efficient synthesis of symmetrical and unsymmetrical proline-type Diketopiperazines using a phosphite-promoted -coupling was used to generate Diketopiperazines with overall good yields from unprotected amino acids.
Jean Martinez - One of the best experts on this subject based on the ideXlab platform.
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A mechanochemical approach to access the proline–proline diketopiperazine framework
Beilstein Journal of Organic Chemistry, 2017Co-Authors: Nicolas Pétry, Hafid Benakki, Eric Clot, Pascal Retailleau, Farhate Guenoun, Fatima Asserar, Chakib Sekkat, Thomas-xavier Metro, Jean Martinez, Frédéric LamatyAbstract:Ball milling was exploited to prepare a substituted proline building block by mechanochemical nucleophilic substitution. Subsequently , the mechanocoupling of hindered proline amino acid derivatives was developed to provide proline-proline dipeptides under solvent-free conditions. A deprotection-cyclization sequence yielded the corresponding Diketopiperazines that were obtained with a high stereoselectivity which could be explained by DFT calculations. Using this method, an enantiopure disubstituted Pro-Pro diketopiperazine was synthesized in 4 steps, making 5 new bonds using a ball mill. 2169
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from Diketopiperazines to hydantoins an unprecedented rearrangement
Synlett, 2014Co-Authors: Guilhem Chaubet, Jean Martinez, Guillaume Cazals, Aurelien Lebrun, Isabelle ParrotAbstract:Bis-Boc-activated 2,5-Diketopiperazines on reaction with potassium hydroxide or sodium methoxide in dry tetrahydrofuran led to Boc-protected hydantoins through an unprecedented ring contraction. This rearrangement was applied to several monosubstituted 2,5-Diketopiperazines with good yields and regioselectivity.
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From Diketopiperazines to Hydantoins: An Unprecedented Rearrangement
Synlett, 2014Co-Authors: Isabelle Parrot, Guillaume Cazals, Guilhem Chaubet, Aurelien Lebrun, Jean MartinezAbstract:International audienceBis-Boc-activated 2,5-Diketopiperazines on reaction with potassium hydroxide or sodium methoxide in dry tetrahydrofuran led to Boc-protected hydantoins through an unprecedented ring contraction. This rearrangement was applied to several monosubstituted 2,5-Diketopiperazines with good yields and regioselectivity
Isabelle Parrot - One of the best experts on this subject based on the ideXlab platform.
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from Diketopiperazines to hydantoins an unprecedented rearrangement
Synlett, 2014Co-Authors: Guilhem Chaubet, Jean Martinez, Guillaume Cazals, Aurelien Lebrun, Isabelle ParrotAbstract:Bis-Boc-activated 2,5-Diketopiperazines on reaction with potassium hydroxide or sodium methoxide in dry tetrahydrofuran led to Boc-protected hydantoins through an unprecedented ring contraction. This rearrangement was applied to several monosubstituted 2,5-Diketopiperazines with good yields and regioselectivity.
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From Diketopiperazines to Hydantoins: An Unprecedented Rearrangement
Synlett, 2014Co-Authors: Isabelle Parrot, Guillaume Cazals, Guilhem Chaubet, Aurelien Lebrun, Jean MartinezAbstract:International audienceBis-Boc-activated 2,5-Diketopiperazines on reaction with potassium hydroxide or sodium methoxide in dry tetrahydrofuran led to Boc-protected hydantoins through an unprecedented ring contraction. This rearrangement was applied to several monosubstituted 2,5-Diketopiperazines with good yields and regioselectivity
Guilhem Chaubet - One of the best experts on this subject based on the ideXlab platform.
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from Diketopiperazines to hydantoins an unprecedented rearrangement
Synlett, 2014Co-Authors: Guilhem Chaubet, Jean Martinez, Guillaume Cazals, Aurelien Lebrun, Isabelle ParrotAbstract:Bis-Boc-activated 2,5-Diketopiperazines on reaction with potassium hydroxide or sodium methoxide in dry tetrahydrofuran led to Boc-protected hydantoins through an unprecedented ring contraction. This rearrangement was applied to several monosubstituted 2,5-Diketopiperazines with good yields and regioselectivity.
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From Diketopiperazines to Hydantoins: An Unprecedented Rearrangement
Synlett, 2014Co-Authors: Isabelle Parrot, Guillaume Cazals, Guilhem Chaubet, Aurelien Lebrun, Jean MartinezAbstract:International audienceBis-Boc-activated 2,5-Diketopiperazines on reaction with potassium hydroxide or sodium methoxide in dry tetrahydrofuran led to Boc-protected hydantoins through an unprecedented ring contraction. This rearrangement was applied to several monosubstituted 2,5-Diketopiperazines with good yields and regioselectivity
Martin Nieger - One of the best experts on this subject based on the ideXlab platform.
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synthesis of new Diketopiperazines thiolation to thioDiketopiperazines and examination of their ros generating properties
European Journal of Organic Chemistry, 2015Co-Authors: Sabilla Zhong, Martin Nieger, Angela E. E. Wandler, Ute Schepers, Stefan BräseAbstract:A variety of new symmetrical and unsymmetrical Diketopiperazines have been prepared from free amino acids by using a previously developed microwave-assisted protocol. This included the successful incorporation of L-pyroglutamic acid as an unusual building block. The Diketopiperazines were then thiolated electrophilically to the corresponding bis(methylthio)- and epidithioDiketopiperazines. Initial experiments showed a promising activity towards the generation of reactive oxygen species in HeLa cells.
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Synthesis of New Diketopiperazines, Thiolation to ThioDiketopiperazines, and Examination of Their ROS‐Generating Properties
European Journal of Organic Chemistry, 2015Co-Authors: Sabilla Zhong, Martin Nieger, Angela E. E. Wandler, Ute Schepers, Stefan BräseAbstract:A variety of new symmetrical and unsymmetrical Diketopiperazines have been prepared from free amino acids by using a previously developed microwave-assisted protocol. This included the successful incorporation of L-pyroglutamic acid as an unusual building block. The Diketopiperazines were then thiolated electrophilically to the corresponding bis(methylthio)- and epidithioDiketopiperazines. Initial experiments showed a promising activity towards the generation of reactive oxygen species in HeLa cells.
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One-Pot Synthesis of Symmetrical and Unsymmetrical Diketopiperazines from Unprotected Amino Acids
Synlett, 2007Co-Authors: Anne Friedrich, Manuel Jainta, Martin Nieger, Stefan BräseAbstract:An efficient synthesis of symmetrical and unsymmetrical proline-type Diketopiperazines using a phosphite-promoted -coupling was used to generate Diketopiperazines with overall good yields from unprotected amino acids.