Synthesis and structures of a chiral phosphine–phosphoric acid ligand and its rhodium(I) complexes

The synthesis and characterization of a novel chiral phosphine–phosphoric acid ligand, (R)-3-diphenylphosphino-1,1′-binaphthyl-2,2′-diyl hydrogenphosphate (2) and its rhodium(I) complexes are described. The single-crystal X-ray diffraction analysis of 2 showed the intermolecular hydrogen-bonding network of the phosphoric acid moiety. The reactions of 2 with [RhCl(cod)]2 in the presence of KOtBu or with [Rh(acac)(CO)2] (acac = acetylacetonate) gave P,O-chelating rhodium(I) complexes [Rh(2–H+)(cod)] 3 or [Rh(2–H+)(CO)]24, respectively. Their molecular structures were determined by single-crystal X-ray diffraction.

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(R)-3-Diphenylphosphino-1,1′-binaphthyl-2,2′-diyl hydrogenphosphate 2C32H22O4P2[α]D25 = −351.3 (c 1.00, CHCl3)Source of chirality: (R)-(+)-1,1′-Bi-2-naphtholAbsolute configuration: (R)

Compound [Rh(2–H+)(cod)] 3C40H33O4P2Rh[α]D24 = +10.3 (c 1.00, CHCl3)Source of chirality: (R)-(+)-1,1′-Bi-2-naphtholAbsolute configuration: (R)

Compound [Rh(2–H+)(CO)]24C66H42O10P4Rh2[α]D23 = +11.0 (c 1.00, CHCl3)Source of chirality: (R)-(+)-1,1′-Bi-2-naphtholAbsolute configuration: (R,R)