Chemical Structure from Scientific Research

The stereoinduction ( c ) arising from three phosphoramidite ligands was compared in an iridium-catalysed allylic substitution ( d ). We hypothesize that the chiral anion formed in situ biases the stereochemical equilibrium of the cationic L BB2 Ir -allyl intermediate, leading to its improved performance relative to the control ligands lacking dynamic sp 3 -C stereochemistry. Reagents and conditions: (iii) 1. [Ir(1,5-cod)Cl 2 ] (4 mol%), ligand (16 mol%), THF, 30 min, r.t. 2. ( R )-BDHP (10 mol%), r.t., 24 h. -TRISPHAT , -tris(tetrachloro-1,2-benzenediolato)phosphate(V); ( S )-BORBIN, bis[( S )-1,1-bis-2-naphtholato]borate; 1,5-cod, 1,5-cyclooctadiene; ( R )-BDHP, ( R )-1,1-binaphthyl-2,2-diyl hydrogen phosphate.

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