Non‐racemic Tin(IV) Complexes Containing P ‐chirogenic Phosphinomethylphenolate Ligands

The chiral Sn IV complexes L*SnMe 2 Cl ( 5 ) and L*SnMe 2 H ( 6 ) containing the P ‐chirogenic o ‐[( t ‐butyl)(phenyl)phosphinomethyl]phenolate ligand (L*) have been synthesized via the respective lithium complex [LiL*] 4 ( 4 ). The synthesis and structure of 4 are described. The stereochemical course of the ligand synthesis was monitored by chiral HPLC and single crystal structure analysis on suitable intermediates. The tin atom in 5 is pentacoordinate by intramolecular phosphine coordination whereas 6 contains tetracoordinate tin without phosphine coordination. Slow racemization of 5 at 100 °C afforded 5‐rac while oxidation with elemental oxygen led under retention of configuration at phosphorus to the phosphinoxide complex o ‐[(tBu)(Ph)P*(O)CH 2 ]C 6 H 4 OSnMe 2 Cl ( 7 ) with P‐O coordination to tin. The compounds 5 , 5‐rac , and 7 were also characterized by X‐ray diffraction.