The synthesis of 13C6-labeled L-thyronine, 3,5-diiodothyronine, 3,3′,5-triiodothyroacetic acid and 3,3′,5,5′-tetraiodothyroacetic acid

The effects of thyroid hormone metabolites (THMs) other than T3, rT3 and T4 are largely unknown, partially due to the lack of adequate methods. For adequate analysis, internal standards for all THMs are essential, but unfortunately not commercially available. Reported approaches for the synthesis of T0, 3,5-T2, TA3 and TA4 lack sensitivity and/or are not adaptable for 13C6-labeled analogues. In this paper, we describe the synthesis of four 13C6-labeled THMs, T0-13C6, 3,5-T2-13C6, TA3-13C6, TA4-13C6. Starting with 13C6-bromo-benzene, a short and versatile synthesis route was developed in which the formation of the diphenyl ether by a Chan-Lam coupling reaction was fundamental

TMTHSI, a superior 7-membered ring alkyne containing reagent for strain-promoted azide-alkyne cycloaddition reactions

We describe the development of TMTH-SulfoxImine (TMTHSI) as a superior click reagent. This reagent combines a great reactivity, with small size and low hydrophobicity and compares outstandingly with existing click reagents. TMTHSI can be conveniently functionalized with a variety of linkers allowing attachment of a diversity of small molecules and (peptide, nucleic acid) biologics