Thomas Zöller

Novel stannatranes of the type N(CH2CMe2O)3SnX (X = OR, SR, OC(O)R, SP(S)Ph2, halogen). Synthesis, molecular structures, and electrochemical properties.

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.

Intramolecular N→Sn coordination in tin(II) and tin(IV) compounds based on enantiopure ephedrine derivatives.

The syntheses and molecular structures of the intramolecularly coordinated tin(II) compounds {CH(2)N(Me)CH(Me)CH(Ph)O}(2)SnL (2, L = lone pair; 4, L = W(CO)(5); 5, L = Cr(CO)(5)) and of the related hydroxido-substituted tin(IV) compound [{CH(2)N(Me)CH(Me)CH(Ph)O}(2)Sn(OH)](2)O, 6a, are reported. Also reported are the molecular structures of the enantiopure N,N-ethylenebis-(1R,2S)-ephedrine, {CH(2)N(Me)CH(Me)CH(Ph)OH}(2) (1), and its hydrobromide {CH(2)N(Me)CH(Me)CH(Ph)OH}(2)·HBr (1a).

Novel Trialkanolamine Derivatives of Tin of the Type [N(CH2CMe2O)2(CH2)nOSnOR]m (m = 1, 2; n = 2, 3; R = t-Bu, 2,6-Me2C6H3) and Related Tri- and Pentanuclear Tin(IV) Oxoclusters. Syntheses and Molecular Structures

The syntheses of the novel alkanolamine N(CH(2)CMe(2)OH)(2)(CH(2)CH(2)CH(2)OH) (2), the novel aminotrialkoxides of tin of the type [N(CH(2)CMe(2)O)(2)(CH(2))(n)OSnOR](m) (3: m = 1, n = 2, R = t-Bu; 4: m = 2, n = 3, R = t-Bu; 5: m = n = 2, R = 2,6-Me(2)C(6)H(3); 6: m = 2, n = 3, R = 2,6-Me(2)C(6)H(3)) and the related trinuclear tin oxoclusters [(LSnOSnL)(LSnOR)] [L = N(CH(2)CMe(2)O)(2)(CH(2)CH(2)O), 7: R = t-Bu; 8: R = 2,6-Me(2)C(6)H(3)] and the pentanuclear tin oxocluster [LSnOSn(OH)(2)OSnL·2LSnOH], [9, L = N(CH(2)CMe(2)O)(2)(CH(2)CH(2)O)] are reported. The compounds are characterized by elemental analyses, multinuclear ((1)H, (13)C, (119)Sn, (1)H-(1)H cosy, (1)H-(13)C HSQC) NMR spectroscopy, electrospray ionization mass spectrometry, and single crystal X-ray diffraction analyses (3, 4·C(7)H(8), 5, 7, 8·0.5C(7)H(8), 9·6H(2)O).

t-Bu2SiF-derivatized D2-receptor ligands: the first SiFA-containing small molecule radiotracers for target-specific PET-imaging.

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.

The 2,8-dioxa-5-aza-1-sila-bicyclo[3.3.01.5]octane PhN(CH2CH2O)2SiH2 as reducing reagent: synthesis and molecular structure of PhN(CH2CH2O)2Sn

Abstract The synthesis of the 2,8-dioxa-5-aza-1-stanna-bicyclo[3.3.01.5]octane [PhN(CH2CH2O)2Sn]n (3) by a combined ligand exchange/redox reaction and independently by the reaction of tin(II)butoxide with N-phenyldiethanolamine is reported. Compound 3 was characterized by elemental analysis and single crystal X-ray diffraction analysis. In the solid state, it is a coordination polymer via intermolecular O→Sn interactions at O-Sn distances of 2.325 (3) and 2.379 (3) Å. The intramolecular N→Sn interactions at distances of 2.818 (3) and 3.096 (3) Å are rather weak.

[4-tBu-2,6-{P(O)(OiPr)2}2C6H2Sn(PPh3)Cr(CO)5]ClO4 – a salt containing a cationic triphenylphosphane-stabilized organostannylene transition metal complex

Abstract The isolation and molecular structure of bis(di-iso-propoxyphosphonyl)-4-tert-butyl]phenyl}tin triphenylphosphane perchlorate chromium pentacarbonyl, 2, is reported. It is the first example of an ionic compound containing an organostannylene transition metal complex cation stabilized by a phosphane donor. Slow reaction of compound 2 in acetonitrile gave trans-bis-triphenylphosphane chromium tetracarbonyl, trans-(Ph3P)2Cr(CO)4, in a new crystalline modification.

Rational Syntheses and Serendipity: Complexes [LSnPtCl2(SMe2)]2, [{LSnPtCl(SMe2)}2SnCl2], [(LSn)3(PtCl2)(PtClSnCl){LSn(Cl)OH}], and [O(SnCl)2(SnL)2] with L=MeN(CH2CMe2O)2

Syntheses and molecular structures of the dimeric tin-platinum complex [LSnPtCl2 (SMe2 )]2 (2), the tin-platinum clusters [{LSnPtCl(SMe2 )}2 SnCl2 )] (3) and [(LSn)3 (PtCl2 )(PtClSnCl)(LSnOHCl)] (6) (L=MeN(CH2 CMe2 O- )2 ), and of the unprecedented tin(II) aminoalkoxide-tin oxide chloride complex [O(SnCl)2 ⋅(SnL)2 ] (5) are reported. The compounds were characterized by NMR spectroscopy (1 H, 13 C, 119 Sn, 195 Pt), 119 Sn Mössbauer spectroscopy (1-3, 6), electrospray ionization mass spectrometry, elemental analyses, and single-crystal X-ray diffraction analyses (2⋅CH2 Cl2 , 3⋅2u2009C4 H8 O, 5, 6⋅3CH2 Cl2 ). The tin(II) aminoalkoxide [MeN(CH2 CMe2 O)2 Sn]2 (1) behaves like a neutral ligand, inserts into a Pt-Cl bond, or is involved in rearrangement reactions with the different behavior occurring even within one compound (3, 6). DFT calculations show that the tin-platinum compounds behave like electronic chameleons.