The homoleptic bis(trimethylsilyl)amides of Group 3 metals and lanthanides of the general type [Ln[N(SiMe3)2]3] (1) (Ln=Y, lanthanide) represent a new class of Tishchenko precatalysts and, to a limited extent, precatalysts for the hydroamination/cyclization of aminoalkynes. It is shown that 1 is the most active catalyst for the Tishchenko reaction. This contribution presents investigations on the scope of the reaction, substrate selectivity, lanthanide-ion size-effect, and kinetic/mechanistic aspects of the Tishchenko reaction catalyzed by 1. The turnover frequency is increased by the use of large-center metals and electron-withdrawing substrates. The reaction rate is second order with respect to the substrate. While donor atoms, such as nitrogen, oxygen, or sulfur, on the substrate decrease the turnover frequency, 1 shows a tolerance for a large number of functional groups. For the hydroamination/cyclization of aminoalkynes, 1 is less active than the well-known metallocene catalysts. On the other hand, 1 is much more readily accessible (one-step synthesis or commercially available), than the metallocenes and might therefore be an attractive alternative catalyst.

The synthesis and characterization of the mono- and bis(N-isopropyl-2-(isopropylamino)troponiminato)yttrium amides [(iPr)2ATI]Y[N(SiMe3)2]2 and [(iPr)2ATI]2Y[N(SiMe3)2], with the corresponding chloro precursors [[(iPr)2ATI]YCl2(THF)2]2 and [(iPr)2ATI]2YCl as starting materials, is reported together with their application as precatalysts for the hydroamination/cyclization of aminoalkynes.

Potassium o-nitrophenolate (1) was reacted with various lanthanide trichlorides under different reaction conditions. By using the smaller lanthanides and working under rigorous exclusion of air, infinite chains of composition [(THF)4[K(o-O2N-C6H4-O)4Ln]4]n (Ln = Y (2a), Er (2b), Lu (2c)) were obtained. Using the same conditions but performing the crystallization under air, tetradecanuclear clusters of composition H18[Ln14(micro-eta2-o-O2N-C6H4-O)8(eta2-o-O2N-C6H4-O)16(micro4-O)2(micro3-O)16] (Ln = Dy (3a), Er (3b), Tm (3c), Yb (3d)) were isolated. Using larger center metals such as samarium, europium, and terbium and working under rigorous exclusion of air, infinite layers of composition [[K2(o-O2N-C6H4-O)5Tb]n] (4) and [[K2(o-O2N-C6H4-O)5Ln)]n] (Ln = Sm (5a), Eu (5b)) were obtained. In 4 the layers have a closer packing than those in compound 5. The closer packing is a result of the increased coordination number of the lanthanide metal and the potassium atoms. In contrast, the more open structures of 5 results in channels which are rectangular through the layers. All compounds reported including 1 have been investigated by single-crystal X-ray diffraction.

Infinite, extended chains or tetradecanuclear lanthanide clusters (see structure) can be formed, depending on conditions, from the reaction of potassium o-nitrophenolate with different lanthanide trichlorides.