Catalytic Dehydrogenation of (Di)Amine-Boranes with a Geometrically Constrained Phosphine-Borane Lewis Pair

Maxime Boudjelel , E. Daiann Sosa Carrizo , Sonia Mallet-Ladeira , Stephane Massou (1) , Karinne Miqueu (2) , Ghenwa Bouhadir (3) , Didier Bourissou (3)

1 UT3 - Université Toulouse III - Paul Sabatier
2 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux
3 LHFA - Laboratoire Hétérochimie Fondamentale et Appliquée

The o-phenylene bridged phosphine-borane iPr2P(o-C6H4)B(Fxyl)2 2 was prepared. Despite ring strain, it adopts a closed form, as substantiated by NMR, XRD, and DFT analyses. However, the corresponding open form is only slightly higher in energy. The dormant Lewis pair 2 proved to efficiently catalyze the dehydrogenation of a variety of amine- and diamine-boranes under mild conditions. The corresponding phosphonium-borate iPr2PH(o-C6H4)BH(Fxyl)2 3 was authenticated as a key intermediate of these dehydrogenation reactions. The propensity of 3 to release H2 plays a major role in the catalytic turnover

Mots clés: amine-borane; dehydrogenation; Lewis pair; metal-free catalysis; phosphine-borane; small molecule activation

Domaines: Chimie théorique et/ou physique; Chimie analytique; Polymères; Matériaux

Maxime Boudjelel, E. Daiann Sosa Carrizo, Sonia Mallet-Ladeira, Stephane Massou, Karinne Miqueu, et al.. Catalytic Dehydrogenation of (Di)Amine-Boranes with a Geometrically Constrained Phosphine-Borane Lewis Pair. ACS Catalysis, 2018, 8 (5), pp.4459 - 4464. ⟨10.1021/acscatal.8b00152⟩. ⟨hal-01834610⟩