Chiral Anion Mediated Asymmetric Induction onto Chiral Diquats

Diquats—which are important electron transfer agents in biological and photocatalytic systems, as well as structural templates for efficient supramolecular synthesis—are noteworthy for their axial chirality and have been so far reported only in racemic form due to the rapid interconversion between the atropoisomers. We now report the first example of configurational ordering of chiral diquats through their asymmetric ion pairing with novel hexacoordinated phosphate anions TRISPHAT, HYPHAT and BINPHAT

Chiral Anion Mediated Asymmetric Induction onto Chiral Diquats

Diquats—which are important electron transfer agents in biological and photocatalytic systems, as well as structural templates for efficient supramolecular synthesis—are noteworthy for their axial chirality and have been so far reported only in racemic form due to the rapid interconversion between the atropoisomers. We now report the first example of configurational ordering of chiral diquats through their asymmetric ion pairing with novel hexacoordinated phosphate anions TRISPHAT, HYPHAT and BINPHAT

NMR Evaluation of the Configurational Stability of Cu(I) Complexes

Association of chiral [CuL2]+ complexes (L = 2-R-phen, 6-R-bpy, and 2-iminopyridine) with TRISPHAT (tris(tetrachlorobenzenediolato)phosphate(V)) anion leads to NMR enantiodifferentiation, which can be used to determine the kinetics of racemization of the complexes

Asymmetric Synthesis and Configurational Stability of C2-Symmetric Hexacoordinated Phosphate Anions (TARPHATs) with Predetermined Chirality from Tartrate Esters

C2-Symmetric TARPHAT anions 5 made of a central PV atom, one tartrato (=dialkyl 2,3-di(hydroxy-KO)butanedioato(2-)), and two tetrachloropyrocatecholato (=3,4,5,6-tetrachlorobenzene-1,2-diolato(2-)-KO,KO) ligands can be easily prepared in decent to high yields (50-86%) as their dimethylammonium salt by using a one-pot process and simple commercially available starting materials. The presence of the chiral tartrato ligands (usually (2R,3R)) leads to the formation of diastereoisomeric anions ((?,2R,3R)/(?,2R,3R)). Decent to good control by the chiral ligands - under equilibration conditions - over the ? or ? configuration of the adducts was observed (d.r. 84 : 16 in CHCl3 for the di(tert-butyl) tartrate derivative), the selectivity depending on the nature of the ester chains as well as on the solvent

Asymmetric Synthesis and Configurational Stability of C2-Symmetric Hexacoordinated Phosphate Anions (TARPHATs) with Predetermined Chirality from Tartrate Esters

C2-Symmetric TARPHAT anions 5 made of a central PV atom, one tartrato (=dialkyl 2,3-di(hydroxy-KO)butanedioato(2-)), and two tetrachloropyrocatecholato (=3,4,5,6-tetrachlorobenzene-1,2-diolato(2-)-KO,KO) ligands can be easily prepared in decent to high yields (50-86%) as their dimethylammonium salt by using a one-pot process and simple commercially available starting materials. The presence of the chiral tartrato ligands (usually (2R,3R)) leads to the formation of diastereoisomeric anions ((?,2R,3R)/(?,2R,3R)). Decent to good control by the chiral ligands - under equilibration conditions - over the ? or ? configuration of the adducts was observed (d.r. 84 : 16 in CHCl3 for the di(tert-butyl) tartrate derivative), the selectivity depending on the nature of the ester chains as well as on the solvent