173166-52-4Relevant articles and documents
Hydrogen activation by an aromatic triphosphabenzene
Longobardi, Lauren E.,Russell, Christopher A.,Green, Michael,Townsend, Nell S.,Wang, Kun,Holmes, Arthur J.,Duckett, Simon B.,McGrady, John E.,Stephan, Douglas W.
, p. 13453 - 13457 (2014)
Aromatic hydrogenation is a challenging transformation typically requiring alkali or transition metal reagents and/or harsh conditions to facilitate the process. In sharp contrast, the aromatic heterocycle 2,4,6-tri-tert -butyl-1,3,5-triphosphabenzene is shown to be reduced under 4 atm of H2 to give [3.1.0]bicylo reduction products, with the structure of the major isomer being confirmed by X-ray crystallography. NMR studies show this reaction proceeds via a reversible 1,4-H2 addition to generate an intermediate species, which undergoes an irreversible suprafacial hydride shift concurrent with P - P bond formation to give the isolated products. Further, para-hydrogen experiments confirmed the addition of H2 to triphosphabenzene is a bimolecular process. Density functional theory (DFT) calculations show that facile distortion of the planar triphosphabenzene toward a boat-conformation provides a suprafacial combination of vacant acceptor and donor orbitals that permits this direct and uncatalyzed reduction of the aromatic molecule.
The metal-initiated cyclooligomerization of phospha-alkynes and its consequences [1]
Mack,Tabellion,Peters,Nachbauer,Bergstraesser,Preuss,Regitz
, p. 261 - 264 (2007/10/03)
1,3-Diphosphacyclobutadienes 4 are almost certainly intermediates in the conversion by hexachloroethane of phosphaalkyne dimer complexes 3 to the tetraphosphacubanes 5. We now describe trapping reactions of 4, generated in the same way, wilh phosphaalkyne 1 (→9), ynamines 10 (→13), and electron-poor alkynes 11 (→14). The cyclooligomerization of 1 initiated by t-Bu-N=VCl3·DME (15) leads to the azatetraphosphaquadricyclanes 20 while the reaction with the stronger Lewis acid t-Bu-N=VCl3 (21) furnishes the 1,3,5-triphosphabenzenes 23 in high selectivity.
η8-cyglooctatetraene metal complexes, a new class of templates for phosphaalkyne cyclooligomerizations
Binger, Paul,Glaser, Gerald,Stannek, J?rg,Leininger, Stefan
, p. 149 - 152 (2007/10/03)
For the first time selective cyclodi-, tri-, and tetramerization of phosphaalkynes are induced by an unique class of transition metal complexes by changing the reaction conditions.