Bulky Phosphinines: From a Molecular Design to an Application in Homogeneous Catalysis

摘要: The design and preparation of an asymmetrically substituted bulky phosphinine was achieved by introducing sterically demanding substituents into specific positions a rigid phosphorus-heterocyclic framework. Compound 5 shows, at the same time, axial chirality sufficiently high energy barrier for internal rotation to prevent enantiomerization. Both enantiomers were isolated means chiral analytical HPLC, their absolute configurations could be assigned combining experimental data DFT calculations. Despite its substitution pattern, can still coordinate transition-metal centers through lone pair electrons on phosphorus atom. Rapid CH activation adjacent aryl substituent 2-position heterocycle using [{Cp*IrCl2}2] (Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) as metal precursor. A racemic mixture applied π-accepting low-coordinate ligand in Rh-catalyzed hydroformylation trans-2-octene, which showed clear preference formation 2-methyloctanal.