Substituted aminotroponimines, {R-ATI(iPr)2}H (R = Br, I, PhN2, NO2, PhS, PhSe, PhTe, 3,5-(CF3)2C6H3S, PhS(O)), bearing different functional groups in the 5-position were prepared. Reaction of these compounds with ZnMe2 in toluene at 0 °C delivered the corresponding methyl zinc complexes [{R-ATI(iPr)2}ZnMe] in high yields. The solid state structures of four selected examples were established via single-crystal X-ray diffraction analysis. In all compounds the zinc atoms are coordinated in a trigonal-planar fashion. All complexes were investigated as catalysts in the intramolecular hydroamination of non-activated alkenes. The attachment of electron-withdrawing groups in the 5-position such as nitro-or sulfoxide decreased the activity of the corresponding zinc catalysts. In contrast, donor substituents such as a thioether moiety at the backbone of the ligand increased the stability of the chelate and also rendered the zinc atom more reactive. On the other hand, the 5-brominated compound is very labile under the catalytic conditions used. In order to study the potential of an additional beneficial effect from the steric environment around the zinc atom on both reactivity and stability of the corresponding complexes, a prototypic ligand bearing a 5-phenylsulfanyl substituent at the backbone and two cyclohexyl substituents at the nitrogen atoms, {PhS-ATI(Cy)2}H, and its corresponding zinc complex, [{PhS-ATI(Cy)2}ZnMe], were synthesized.

No abstract

No abstract

We have prepared digold(I) complexes with the rigid-backbone diphosphane ligands PhanePhos, xyl-PhanePhos, and Ph 2 -GemPhos. All complexes were characterized by singlecrystal X-ray diffraction, NMR, IR, Raman, and photoluminescence (PL) spectroscopy. [PhanePhos(AuCl) 2 ] and [Gem-Phos(AuCl) 2 ] show a very similar ligand scaffold, but different (aurophilic vs. nonaurophilic) intramolecular Au-Au distances. Absorption and PL spectra of both compounds are quite similar. Theoretical investigations reveal that the excited states are of different character (i.e., influenced by the Au-Au contacts). The respective transition energies, however, lie close to each other, thus resulting in similar experi-

No abstract

The Zn-Zn bonded compound [(η(5)-Cp*)(2)Zn(2)] was investigated as catalyst for the inter- and intramolecular hydroamination reaction. High reaction rates under mild conditions were observed. This is the first application of a Zn-Zn bonded compound as catalyst.

A comparison of the Zn−Zn bonded species [(η 5 -Cp*) 2 Zn 2 ] versus the related organometallic zinc compound [Cp* 2 Zn] and ZnEt 2 for the intermolecular hydroamination reaction in the presence of equimolar amounts of [PhNMe 2 H][B(C 6 F 5 ) 4 ] is reported. All compounds show high reaction rates under mild conditions and a good functional group tolerance for the addition of aniline derivatives to primary alkynes. Within this series the metallocene [Cp* 2 Zn] is the most active one, whereas the zinc−zinc bonded species [(η 5 -Cp*) 2 Zn 2 ] shows the best selectivity. Most remarkable is the unexpected excellent catalytic performance of the zinc−zinc bonded species [(η 5 -Cp*) 2 Zn 2 ].

No abstract