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Abstract A new series of mono‐ and bis‐alkynyl CoIII(TIM) complexes (TIM=2,3,9,10‐tetramethyl‐1,4,8,11‐tetraazacyclotetradeca‐1,3,8,10‐tetraene) is reported herein. Thetrans‐[Co(TIM)(C2R)Cl]+complexes were prepared from the reaction betweentrans‐[Co(TIM)Cl2]PF6and HC2R (R=tri(isopropyl)silyl or TIPS (1), ‐C6H4‐4‐tBu (2), ‐C6H4‐4‐NO2(3 a), andN‐mesityl‐1,8‐naphthalimide or NAPMes(4 a)) in the presence of Et3N. The intermediate complexes of the typetrans‐[Co(TIM)(C2R)(NCMe)](PF6)(OTf),3 band4 b, were obtained by treating3 aand4 a, respectively, with AgOTf in CH3CN. Furthermore, bis‐alkynyltrans‐[Co(TIM)(C2R)2]PF6complexes,3 cand4 c, were generated following a second dehydrohalogenation reaction between3 band4 b, respectively, and the appropriate HC2R in the presence of Et3N. These new complexes have been characterized using X‐ray diffraction (2,3 a,4 a, and4 c), IR,1H NMR, UV/Vis spectroscopy, fluorescent spectroscopy (4 c), and cyclic voltammetry.
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Tritium hydrogen‐isotope exchange with electron‐poor tertiary benzenesulfonamide moiety; application in late‐stage labeling of T0901317
The multifunctional radioligand [3H]T0901317 ([3H]1) has been employed as a powerful autoradiographic tool to target several receptors, such as liver X, farnesoid X, and retinoic acid‐related orphan receptor alpha and gamma subtypes at nanomolar concentrations. Although [3H]1is commercially available and its synthesis via tritiodebromination has been reported, the market price of this radioligand and the laborious synthesis of corresponding bromo‐intermediate potentially preclude its widespread use in biochemical, pharmacological, and pathological studies in research lab settings. We exploit recent reports on hydrogen‐isotope exchange (HIE) reactions in tertiary benzenesulfonamides where the sulfonamide represents anortho‐directing group that facilitates CH activation in the presence of homogenous iridium(I) catalysts. Herein, we report a time‐ and cost‐efficient method for the tritium late‐stage labeling of compound1—a remarkably electron‐poor substrate owing to the tertiary trifluoroethylsulfonamide moiety. Under a straightforward HIE condition using a commercially available Kerr‐type NHC Ir(I) complex, [(cod)Ir (NHC)Cl], the reaction with1afforded a specific activity of 10.8 Ci/mmol. Additionally, alternative HIE conditions using the heterogeneous catalyst of Ir‐black provided sufficient 0.72 D‐enrichment of1but unexpectedly failed while repeating with tritium gas.
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- Award ID(s):
- 1951518
- PAR ID:
- 10362240
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Labelled Compounds and Radiopharmaceuticals
- Volume:
- 65
- Issue:
- 2
- ISSN:
- 0362-4803
- Format(s):
- Medium: X Size: p. 36-44
- Size(s):
- p. 36-44
- Sponsoring Org:
- National Science Foundation
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