Sterically Crowded, Rigid,C3Symmetric Phosphites: Synthesis, Structure, and Preparation of Metal Complexes

The sterically congested, rigid, C 3 symmetric phosphites ( 2a − e ) have been synthesized by reaction of PCl 3 with the corresponding tris(3,5-dialkyl-2-hydroxyphenyl)methanes (3,5-di- tert -butyl; 3- tert -butyl-5-methyl; 3,5-di- tert -pentyl; 3-adamantyl-5-methyl; 3,5-dimethyl) and characterized. The arsenite derivative ( 3b ) of tris(3- tert -butyl-5-methyl-2-hydroxyphenyl)methane was similarly prepared by reaction with AsI 3 . Both the phosphite 2a and the arsenite derivative 3b have been examined by single-crystal X-ray analyses. Metal complexes ( 4 − 6 ) of the phosphites were prepared by reaction of the phosphite with [PdCl 2 (cod]) (cod = 1,5-cyclooctadiene), [PdCl( η 3 -C 3 H 5 )] 2 and [Rh(CO) 2 (acac)] (acac = acetylacetonate), respectively, and examples of each are represented by X-ray structure determinations.