Preparation of a rigid bicyclic diphosphine by radical cyclisation

Palladium-Catalyzed Regio- and Enantioselective Hydrophosphination of gem-Difluoroallenes

Chiral allylic phosphines and gem-difluoroalkenes are both important structural motifs in various bioactive molecules, chiral ligands, and natural products. These two motifs are now integrated, and we herein report a straightforward and atom-economical enantioselective hydrophosphination of gem-difluoroallenes using disubstituted phosphines. A wide array of enantioenriched fluorinated allylic phosphines has been accessed with excellent regio- and enantioselectivity and high efficiency. Synthetic and catalytic applications of phosphine products have been demonstrated.

Nickel/Brønsted acid dual-catalyzed regio- and enantioselective hydrophosphinylation of 1,3-dienes: access to chiral allylic phosphine oxides

While chiral allylic organophosphorus compounds are widely utilized in asymmetric catalysis and for accessing bioactive molecules, their synthetic methods are still very limited. We report the development of asymmetric nickel/Brønsted acid dual-catalyzed hydrophosphinylation of 1,3-dienes with phosphine oxides. This reaction is characterized by an inexpensive chiral catalyst, broad substrate scope, and high regio- and enantioselectivity. This study allows the construction of chiral allylic phosphine oxides in a highly economic and efficient manner. Preliminary mechanistic investigations suggest that the 1,3-diene insertion into the chiral Ni-H species is a highly regioselective process and the formation of the chiral C-P bond is an irreversible step.

[1,3]/[1,4]-Sulfur atom migration in β-hydroxyalkylphosphine sulfides

β-Hydroxyalkylphosphine sulfides undergo [1,3]- or [1,4]-sulfur atom phosphorus-to-carbon migration in the presence of Lewis or Brønsted acids. The direction of sulfur atom migration depends on the type of acid used for the reaction. In the presence of a Brønsted acid, mainly [1,3]-rearrangement is observed, whereas a Lewis acid catalyzes the [1,4]-sulfur migration. To gain insight into the mechanism of these transformations, the stereochemistry of these rearrangements have been tested, along with the conduction of some control experiments and DFT calculations.

Practical Rh(I)-Catalyzed Asymmetric Hydrogenation of β-(Acylamino)acrylates Using a New Unsymmetrical Hybrid Ferrocenylphosphine−Phosphoramidite Ligand: Crucial Influence of an N−H Proton in the Ligand

[reaction: see text] Excellent enantioselectivities and high turnovers (S/C = 5000) were achieved in the Rh(I)-catalyzed asymmetric hydrogenation of both beta-aryl- and beta-alkyl-beta-(acylamino)acrylates with a new unsymmetrical hybrid ferrocenylphosphine-phosphoramidite ligand, and the presence of an N-H proton in the ligand was demonstrated to have a crucial role in the enantioselectivity.