The Experts below are selected from a list of 816 Experts worldwide ranked by ideXlab platform
Dale O. Kiesewetter - One of the best experts on this subject based on the ideXlab platform.
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3 18f fluoropropane 1 thiol and 18f peg4 1 thiol versatile prosthetic groups for radiolabeling maleimide functionalized peptides
Bioorganic & Medicinal Chemistry, 2019Co-Authors: Orit Jacobson, Xiaoyuan Chen, Guocan Yu, Zhantong Wang, Dale O. KiesewetterAbstract:Abstract The efficient radioSynthesis of biomolecules utilizing minute quantities of maleimide substrate is important for availability of novel peptide molecular imaging agents. We evaluated both 3-18F-fluoropropane-1-thiol and 2-(2-(2-(2-18F-fluoroethoxy)ethoxy)ethoxy)ethane-1-thiol (18F-fluoro-PEG4 thiol) as prosthetic groups for radiolabeling under physiological conditions. The precursor employed a benzoate for protection of the thiol and an arylsulfonate leaving group. The radiofluorination was fully automated on an Eckert & Ziegler Synthesis system using standard Kryptofix222/K2CO3 conditions. In order to minimize the amount of biological molecule required for subsequent conjugation, the intermediates, S-(3-18F-fluoropropyl) benzothioate and 18F-fluoro-PEG4 benzothioate, were purified by HPLC. The intermediates were isolated from the HPLC in yields of 37–47% and 28–35%, respectively, and retrieved from eluate using solid phase extraction. Treatment of the benzothioates with sodium methoxide followed by acetic acid provided the free thiols. The desired maleimide substrate in acetonitrile or phosphate buffer was then added and incubated at room temperature for 15 min. The final radiolabeled bioconjugate was purified on a separate HPLC or NAP-5 column. Maleimides utilized for the coupling reaction included phenyl maleimide, an Evans Blue maleimide derivative, a dimeric RGDfK maleimide (E[c(RGDfK)]2), two aptamer maleimides, and PSMA maleimide derivative. Isolated radiochemical yields (non-decay corrected) of maleimide addition products based on starting 18F-fluoride ranged from 6 to 22% in a Synthesis time of about 90 min. 18F-thiol prosthetic groups were further tested in vivo by conjugation to E[c(RGDfK)]2 maleimide in a U87MG xenograft model. PET studies demonstrated similar tumor accumulation of both prosthetic groups. 18F-fluoro-PEG4-S-E[c(RGDfK)]2 displayed a somewhat favorable pharmacokinetics compared to 18F-fluoropropyl-S-E[c(RGDfK)]2. Bone uptake was low for both indicating in vivo stability.
Timothy Noel - One of the best experts on this subject based on the ideXlab platform.
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a mild one pot stadler Ziegler Synthesis of arylsulfides facilitated by photoredox catalysis in batch and continuous flow
ChemInform, 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:This novel one-pot Stadler-Ziegler process reduces two potential explosion hazards: the need for diazonium salt isolation is eliminated and the formation of diazosulfides is minimized.
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A Mild, One‐Pot Stadler—Ziegler Synthesis of Arylsulfides Facilitated by Photoredox Catalysis in Batch and Continuous‐Flow.
ChemInform, 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:This novel one-pot Stadler-Ziegler process reduces two potential explosion hazards: the need for diazonium salt isolation is eliminated and the formation of diazosulfides is minimized.
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a mild one pot stadler Ziegler Synthesis of arylsulfides facilitated by photoredox catalysis in batch and continuous flow
Angewandte Chemie, 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:Visible advance: A mild, one-pot Stadler-Ziegler process for C-S bond formation has been developed. The method employs the photoredox catalyst [Ru(bpy)3Cl2]⋅6 H2O irradiated with visible light. A variety of aryl-alkyl and diaryl sulfides were prepared from readily available arylamines and aryl/alkylthiols in good yields. The use of a photo microreactor led to a significant improvement with respect to safety and efficiency.
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A Mild, One‐Pot Stadler–Ziegler Synthesis of Arylsulfides Facilitated by Photoredox Catalysis in Batch and Continuous‐Flow
Angewandte Chemie (International ed. in English), 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:Visible advance: A mild, one-pot Stadler-Ziegler process for C-S bond formation has been developed. The method employs the photoredox catalyst [Ru(bpy)3Cl2]⋅6 H2O irradiated with visible light. A variety of aryl-alkyl and diaryl sulfides were prepared from readily available arylamines and aryl/alkylthiols in good yields. The use of a photo microreactor led to a significant improvement with respect to safety and efficiency.
Orit Jacobson - One of the best experts on this subject based on the ideXlab platform.
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3 18f fluoropropane 1 thiol and 18f peg4 1 thiol versatile prosthetic groups for radiolabeling maleimide functionalized peptides
Bioorganic & Medicinal Chemistry, 2019Co-Authors: Orit Jacobson, Xiaoyuan Chen, Guocan Yu, Zhantong Wang, Dale O. KiesewetterAbstract:Abstract The efficient radioSynthesis of biomolecules utilizing minute quantities of maleimide substrate is important for availability of novel peptide molecular imaging agents. We evaluated both 3-18F-fluoropropane-1-thiol and 2-(2-(2-(2-18F-fluoroethoxy)ethoxy)ethoxy)ethane-1-thiol (18F-fluoro-PEG4 thiol) as prosthetic groups for radiolabeling under physiological conditions. The precursor employed a benzoate for protection of the thiol and an arylsulfonate leaving group. The radiofluorination was fully automated on an Eckert & Ziegler Synthesis system using standard Kryptofix222/K2CO3 conditions. In order to minimize the amount of biological molecule required for subsequent conjugation, the intermediates, S-(3-18F-fluoropropyl) benzothioate and 18F-fluoro-PEG4 benzothioate, were purified by HPLC. The intermediates were isolated from the HPLC in yields of 37–47% and 28–35%, respectively, and retrieved from eluate using solid phase extraction. Treatment of the benzothioates with sodium methoxide followed by acetic acid provided the free thiols. The desired maleimide substrate in acetonitrile or phosphate buffer was then added and incubated at room temperature for 15 min. The final radiolabeled bioconjugate was purified on a separate HPLC or NAP-5 column. Maleimides utilized for the coupling reaction included phenyl maleimide, an Evans Blue maleimide derivative, a dimeric RGDfK maleimide (E[c(RGDfK)]2), two aptamer maleimides, and PSMA maleimide derivative. Isolated radiochemical yields (non-decay corrected) of maleimide addition products based on starting 18F-fluoride ranged from 6 to 22% in a Synthesis time of about 90 min. 18F-thiol prosthetic groups were further tested in vivo by conjugation to E[c(RGDfK)]2 maleimide in a U87MG xenograft model. PET studies demonstrated similar tumor accumulation of both prosthetic groups. 18F-fluoro-PEG4-S-E[c(RGDfK)]2 displayed a somewhat favorable pharmacokinetics compared to 18F-fluoropropyl-S-E[c(RGDfK)]2. Bone uptake was low for both indicating in vivo stability.
Xiao Wang - One of the best experts on this subject based on the ideXlab platform.
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a mild one pot stadler Ziegler Synthesis of arylsulfides facilitated by photoredox catalysis in batch and continuous flow
ChemInform, 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:This novel one-pot Stadler-Ziegler process reduces two potential explosion hazards: the need for diazonium salt isolation is eliminated and the formation of diazosulfides is minimized.
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A Mild, One‐Pot Stadler—Ziegler Synthesis of Arylsulfides Facilitated by Photoredox Catalysis in Batch and Continuous‐Flow.
ChemInform, 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:This novel one-pot Stadler-Ziegler process reduces two potential explosion hazards: the need for diazonium salt isolation is eliminated and the formation of diazosulfides is minimized.
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a mild one pot stadler Ziegler Synthesis of arylsulfides facilitated by photoredox catalysis in batch and continuous flow
Angewandte Chemie, 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:Visible advance: A mild, one-pot Stadler-Ziegler process for C-S bond formation has been developed. The method employs the photoredox catalyst [Ru(bpy)3Cl2]⋅6 H2O irradiated with visible light. A variety of aryl-alkyl and diaryl sulfides were prepared from readily available arylamines and aryl/alkylthiols in good yields. The use of a photo microreactor led to a significant improvement with respect to safety and efficiency.
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A Mild, One‐Pot Stadler–Ziegler Synthesis of Arylsulfides Facilitated by Photoredox Catalysis in Batch and Continuous‐Flow
Angewandte Chemie (International ed. in English), 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:Visible advance: A mild, one-pot Stadler-Ziegler process for C-S bond formation has been developed. The method employs the photoredox catalyst [Ru(bpy)3Cl2]⋅6 H2O irradiated with visible light. A variety of aryl-alkyl and diaryl sulfides were prepared from readily available arylamines and aryl/alkylthiols in good yields. The use of a photo microreactor led to a significant improvement with respect to safety and efficiency.
Gregory D Cuny - One of the best experts on this subject based on the ideXlab platform.
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a mild one pot stadler Ziegler Synthesis of arylsulfides facilitated by photoredox catalysis in batch and continuous flow
ChemInform, 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:This novel one-pot Stadler-Ziegler process reduces two potential explosion hazards: the need for diazonium salt isolation is eliminated and the formation of diazosulfides is minimized.
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A Mild, One‐Pot Stadler—Ziegler Synthesis of Arylsulfides Facilitated by Photoredox Catalysis in Batch and Continuous‐Flow.
ChemInform, 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:This novel one-pot Stadler-Ziegler process reduces two potential explosion hazards: the need for diazonium salt isolation is eliminated and the formation of diazosulfides is minimized.
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a mild one pot stadler Ziegler Synthesis of arylsulfides facilitated by photoredox catalysis in batch and continuous flow
Angewandte Chemie, 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:Visible advance: A mild, one-pot Stadler-Ziegler process for C-S bond formation has been developed. The method employs the photoredox catalyst [Ru(bpy)3Cl2]⋅6 H2O irradiated with visible light. A variety of aryl-alkyl and diaryl sulfides were prepared from readily available arylamines and aryl/alkylthiols in good yields. The use of a photo microreactor led to a significant improvement with respect to safety and efficiency.
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A Mild, One‐Pot Stadler–Ziegler Synthesis of Arylsulfides Facilitated by Photoredox Catalysis in Batch and Continuous‐Flow
Angewandte Chemie (International ed. in English), 2013Co-Authors: Xiao Wang, Gregory D Cuny, Timothy NoelAbstract:Visible advance: A mild, one-pot Stadler-Ziegler process for C-S bond formation has been developed. The method employs the photoredox catalyst [Ru(bpy)3Cl2]⋅6 H2O irradiated with visible light. A variety of aryl-alkyl and diaryl sulfides were prepared from readily available arylamines and aryl/alkylthiols in good yields. The use of a photo microreactor led to a significant improvement with respect to safety and efficiency.
