Synthesis of 5-Fluoroalkylated Pyrimidine Nucleosides via Negishi Cross-Coupling
摘要:
5-Fluoroalkylated pyrimidine nucleosides (1) have potential as therapeutic agents and molecular imaging agents targeting HSV1-tk suicide gene therapy. Thus, straightforward preparation of 5-fluoroalkylated nucleoside derivatives has been developed. Reported herein are the first examples of Pd-catalyzed Negishi cross-coupling of 3-N-benzoyl-3',5'-di-O-benzoyl-5-iodo-2'-deoxyuridine (2a) and 3-N-benzoyl-3',5'-di-O-benzoyl-5-iodo-2'-deoxy-2'-fluoroarabinouridine (2b) with unactivated CSp(3) fluoroalkylzinc bromides. This paper demonstrates the first synthesis of six 5-fluoroalkyl-2'-deoxypyrimidine nucleoside derivatives with three to five methylene chain lengths (5). Furthermore, this methodology has been extended to create a series of 13 5-alkyl-substituted nucleosides, including the target nucleosides 5 and 5-silyloxypropyl and 5-cyanobutyl derivatives.
Synthesis of 5-Fluoroalkylated Pyrimidine Nucleosides via Negishi Cross-Coupling
摘要:
5-Fluoroalkylated pyrimidine nucleosides (1) have potential as therapeutic agents and molecular imaging agents targeting HSV1-tk suicide gene therapy. Thus, straightforward preparation of 5-fluoroalkylated nucleoside derivatives has been developed. Reported herein are the first examples of Pd-catalyzed Negishi cross-coupling of 3-N-benzoyl-3',5'-di-O-benzoyl-5-iodo-2'-deoxyuridine (2a) and 3-N-benzoyl-3',5'-di-O-benzoyl-5-iodo-2'-deoxy-2'-fluoroarabinouridine (2b) with unactivated CSp(3) fluoroalkylzinc bromides. This paper demonstrates the first synthesis of six 5-fluoroalkyl-2'-deoxypyrimidine nucleoside derivatives with three to five methylene chain lengths (5). Furthermore, this methodology has been extended to create a series of 13 5-alkyl-substituted nucleosides, including the target nucleosides 5 and 5-silyloxypropyl and 5-cyanobutyl derivatives.
Synthesis of 5-Fluoroalkylated Pyrimidine Nucleosides via Negishi Cross-Coupling
作者:Ann-Marie Chacko、Wenchao Qu、Hank F. Kung
DOI:10.1021/jo800444y
日期:2008.7.1
5-Fluoroalkylated pyrimidine nucleosides (1) have potential as therapeutic agents and molecular imaging agents targeting HSV1-tk suicide gene therapy. Thus, straightforward preparation of 5-fluoroalkylated nucleoside derivatives has been developed. Reported herein are the first examples of Pd-catalyzed Negishi cross-coupling of 3-N-benzoyl-3',5'-di-O-benzoyl-5-iodo-2'-deoxyuridine (2a) and 3-N-benzoyl-3',5'-di-O-benzoyl-5-iodo-2'-deoxy-2'-fluoroarabinouridine (2b) with unactivated CSp(3) fluoroalkylzinc bromides. This paper demonstrates the first synthesis of six 5-fluoroalkyl-2'-deoxypyrimidine nucleoside derivatives with three to five methylene chain lengths (5). Furthermore, this methodology has been extended to create a series of 13 5-alkyl-substituted nucleosides, including the target nucleosides 5 and 5-silyloxypropyl and 5-cyanobutyl derivatives.
Synthesis and in Vitro Evaluation of 5-[<sup>18</sup>F]Fluoroalkyl Pyrimidine Nucleosides for Molecular Imaging of Herpes Simplex Virus Type 1 Thymidine Kinase Reporter Gene Expression
作者:Ann-Marie Chacko、Wenchao Qu、Hank F. Kung
DOI:10.1021/jm800501d
日期:2008.9.25
Two novel series of 5-fluoroalkyl-2'-deoxyuridines (FPrDU, FBuDU, FPeDU) and 2'-fluoro-2'-deoxy-5-fluoroalkylarabinouridines (FFPrAU, FFBuAU, FFPeAU) that have three, four, or five methylene units (propyl, butyl, or pentyl) at C-5 were prepared and tested as reporter probes for imaging herpes simplex virus type I thymidine kinase (HSV1-tk) gene expression. The Negishi coupling methodology was employed in efficiently synthesizing the radiolabeling precursors. All six 5-[F-18]fluoroalkyl pyrimidines were readily prepared from 3-N-benzoyl-3',5'-di-O-benzoyl-protected 5-O-mesylate Precursors in 17-35% radiochemical yield (decay-corrected). In vitro studies highlighted that all six [F-18]-labeled nucleosides selectively accumulated in cells expressing the HSV1-TK protein and there was negligible uptake in control cells. [F-18]FPrDU, [F-18]FBuDU, [F-18]FPeDU, and [F-18]FFBuAU had the best uptake profiles. Despite their selective accumulation in HSV1-tk-expressing cells, all 5-fluoroalkyl pyrimidine nucleosides had low-to-negligible cytotoxic activity (CC50 > 1000-1209 mu M). Ultimately, the results demonstrated that 5-[F-18]fluoropropyl, [F-18]fluorobutyl, and [F-18]fluoropentyl pyrimidine nucleosides have the potential to be in vivo HSV1-TK PET reporter probes over a dynamic range of reporter gene expression levels.