Reactivity differences between 2,4- and 2,5-disubstituted zirconacyclopentadienes: a highly selective and general approach to 2,4-disubstituted phospholes.

Guillaume Bousrez (1) , Florian Jaroschik (1) , Agathe Martinez (1) , Dominique Harakat (1) , Emmanuel Nicolas (2) , X. F Le Goff (2) , Jan Szymoniak (1)

1 ICMR - Institut de Chimie Moléculaire de Reims - UMR 7312
2 DCPH - Laboratoire Hétéroéléments et Coordination

Mixtures of 2,4- and 2,5-disubstituted zirconacyclopentadienes were obtained by the reductive dimerisation of terminal alkynes using the Cp2ZrCl2/lanthanum system. Reactions of dihalophosphines with these mixtures afforded selectively the corresponding 2,4-disubstituted phospholes and 1,4-disubstituted butadienes. A new series of phospholes was characterized by multi-nuclear NMR spectroscopy and X-ray analysis. A possible explanation for the observed selectivity was obtained from X-ray studies and DFT analysis of the intermediate zirconacyclopentadienes.

Domains: Chemical Sciences; Inorganic chemistry

Guillaume Bousrez, Florian Jaroschik, Agathe Martinez, Dominique Harakat, Emmanuel Nicolas, et al.. Reactivity differences between 2,4- and 2,5-disubstituted zirconacyclopentadienes: a highly selective and general approach to 2,4-disubstituted phospholes.. Dalton Transactions, 2013, epub ahead of print. ⟨10.1039/c3dt51158h⟩. ⟨hal-00839784⟩