The syntheses of the stannatrane derivatives of the type N(CH(2)CMe(2)O)(3)SnX (1, X = Ot-Bu; 2, X = Oi-Pr; 3, X = 2,6-Me(2)C(6)H(3)O; 4, X = p-t-BuC(6)H(4)O; 5, X = p-NO(2)C(6)H(4)O; 6, X = p-FC(6)H(4)O; 7, X = p-PPh(2)C(6)H(4)O; 8, X = p-MeC(6)H(4)S; 9, X = o-NH(2)C(6)H(4)O; 10, X = OCPh(2)CH(2)NMe(2); 11, X = Ph(2)P(S)S; 12, X = p-t-BuC(6)H(4)C(O)O; 13, X = Cl; 14, X = Br; 15, X = I; 16, X = p-N(CH(2)CMe(2)O)(3)SnOSiMe(2)C(6)H(4)SiMe(2)O) are reported. The compounds are characterized by X-ray diffraction analyses (3-8, 11-16), multinuclear NMR spectroscopy, (13)C CP MAS (14) and (119)Sn CP MAS NMR (13, 14) spectroscopy, mass spectrometry and osmometric molecular weight determination (13). Electrochemical measurements show that anodic oxidation of the stannatranes 4 and 8 occurs via electrochemically reversible electron transfer resulting in the corresponding cation radicals. The latter were detected by cyclic voltammetry (CV) and real-time electron paramagnetic resonance spectroscopy (EPR). DFT calculations were performed to compare the stannatranes 4, 8, and 13 with the corresponding cation radicals 4(+•), 8(+•), and 13(+•), respectively.

The syntheses of the tin compounds [LSn]2 (2), spiro‐L2Sn (3), [LSnW(CO)5]2 (4), [LSnBr2]2 (5), spiro‐L2Sn·SnBr4 (6) and LSn[OC(O)Ph]2 (8), where L = MeN(CH2CMe2O)[(S)‐CH(Me)‐(R)‐CH(Ph)O], and (Ph4P)2SnBr6 (7) are reported. The compounds were characterized by elemental analysis, multinuclear NMR spectroscopy including 119Sn cross polarisation–magic angle spinning NMR (CP–MAS) (2, 3–6), electrospray ionization mass spectrometry (2–4) and single crystal X‐ray diffraction analysis (2, 2·C7H8, 3a, 3b, 4·C7H8, 5, 6·C7H8, 7).

The synthesis, radiolabeling and in vitro evaluation of new silicon-fluoride acceptor (SiFA) derivatized D2-receptor ligands is reported. The SiFA-technology simplifies the introduction of fluorine-18 into target specific biomolecules for Positron-Emission-Tomography (PET). However, one of the remaining challenges, especially for small molecules such as receptor-ligands, is the bulkiness of the SiFA-moiety. We therefore synthesized four Fallypride SiFA-conjugates derivatized either directly at the benzoic acid ring system (SiFA-DMFP, SiFA-FP, SiFA-DDMFP) or at the butyl-side chain (SiFA-M-FP) and tested their receptor affinities. We found D2-receptor affinities for all compounds in the nanomolar range (Ki(SiFA-DMFP) = 13.6 nM, Ki(SiFA-FP) = 33.0 nM, Ki(SiFA-DDMFP) = 62.7 nM and Ki(SiFA-M-FP) = 4.21 nM). The radiofluorination showed highest yields when 10 nmol of the precursors were reacted with [18F]fluoride/TBAHCO3 in acetonitrile. After a reversed phased cartridge purification the desired products could be isolated as an injectable solution after only 10 min synthesis time with radiochemical yields (RCY) of more than 40% in the case of SiFA-DMFP resulting in specific activities >41 GBq/µmol (>1,100 Ci/mmol). Furthermore, the radiolabeled products were shown to be stable in the injectable solutions, as well as in human plasma, for at least 90 min.

Extending the classical reactivity pattern of tin: Elemental tin reacts with alcohols to give, depending on the identity of the alcohol and the reaction conditions, a variety of tin alcoholates and tinoxo clusters (see scheme).

The syntheses of new potentially tetradentate ligands of the type RN(CH 2 CMe 2 OH) 2 (1, R = Me 2 NCH 2 CH 2 ; 2, R = MeOCH 2 CH 2 ), their tin(II) derivatives RN(CH 2 CMe 2 O) 2 Sn (3, R = Me 2 NCH 2 CH 2 ; 4, R = MeOCH 2 CH 2 ), the pentacarbonyltungsten complexes RN(CH 2 CMe 2 O) 2 SnW(CO) 5 (5, R = Me 2 NCH 2 CH 2 ; 6, R = MeOCH 2 CH 2 ) and their oxidation products with bromine, RN(CH 2 CMe 2 O) 2 SnBr 2 (7, R = [a]Me 2 NCH 2 CH 2 ; 8, R = MeOCH 2 CH 2 ), are reported. The compounds were characterized by multinuclear NMR spectroscopy, elemental analysis, electrospray ionization mass spectrometry and single-crystal X-ray diffraction analysis. DFT calculations on compounds 3, 7 and 8 suggest the preference of dimeric over monomeric structures.Scheme 4. Synthesis of the compounds 5-8.