Isolation of a Diylide‐Stabilized Stannylene and Germylene: Enhanced Donor Strength through Coplanar Lone Pair Alignment

Abstract

The preparation of the first stable diylide‐substituted stannylene and germylene ( Y 2 E, with E=Ge, Sn and Y=[PPh 3 ‐C‐SO 2 Tol] − ) is reported. The synthesis is easily accomplished in one step from the sulfonyl‐substituted metalated ylide YNa and the corresponding ECl 2 precursors. Y 2 Ge and Y 2 Sn exhibit unusual structures in the solid state and in solution, in which the three adjacent lone pairs in the C‐E‐C linkage are arranged coplanar to each other. As shown by DFT studies, this bonding situation is preferred over the typical π‐donation from the ligands into the empty p‐orbital at the metal due to the strong anion‐stabilizing ability of the sulfonyl groups in the ylide backbone and their additional coordination to the metal. The alignment of the three lone pairs leads to a remarkable boost of the HOMO energy and thus of the donor strengths of the tetrylenes. Hence, Y 2 Ge and Y 2 Sn become stronger donors than their diamino or diaryl congeners and comparable to cyclic alkyl(amino)carbenes. First reactivity studies confirm the high reactivity of Y 2 Ge and Y 2 Sn , which for example undergo an intramolecular C−H activation reaction via metal–ligand cooperation.

Phosphorus-ylides: powerful substituents for the stabilization of reactive main group compounds

“…8 ). 57 The ease of this synthesis demonstrated the utility of group 1 yldiides in accessing ylide-functionalized main group species. XRD analyses revealed unusual structures of both compounds.…”

Ylide‐Stabilized Phosphenium Cations: Impact of the Substitution Pattern on the Coordination Chemistry

“…[14] With the isolation of metalated ylides as versatile reagents for ylide-functionalization we were able to generate the first diylide-substituted boron cations [15] and heavier tetrylenes. [16] Furthermore, the introduction of ylide substituents in phosphines led to a remarkable increase of their donor capacity and hence to excellent performance in gold [17] and palladium catalysis. [18] This led us to re-investigate the chemistry of ylide-substituted phosphenium cations to evaluate their potential as ligands in transition metal chemistry.…”

Calix[4]pyrrolatostannat(II): Ein Tetraamidozinn(II)dianion als starker, metallzentrierter σ‐Donor

“…B. Amidinatostannylen D in Abbildung 1). [4,5] Die Koordination anionischer Liganden an Sn II kann zu einer noch ausgeprägteren Erhöhung der σ-Donorstärke führen, wie dies für die Klasse der nukleophilen anionischen Stannate(II), R 3 Sn À , nachgewiesen wurde. [6] So bewirkt beispielsweise der dreizähnige Amidoligand in Gades Amidostannat(II) [E] À eine solvatationskorrigierte HOMO-Energie von À 3.93 eV.…”