Sterically crowded, rigid, C-3 symmetric phosphites: Synthesis, structure,and preparation of metal complexes

The sterically congested, rigid, C-3 symmetric phosphites (2a-e) have been synthesized by reaction of PCl3 with the corresponding tris(3,5-dialkyl-2-h ydroxyphenyl)methanes (3,5-di-rert-butyl; 3-tert-butyl-5-methyl; 3,5-di-ter t-pentyl; 3-adamantyl-5-methyl; 3,5-dimethyl) and characterized. The arseni te derivative (3b) of tris(3-tert-butyl-5-methyl-2-hydroxyphenyl)methane wa s similarly prepared by reaction with AsI3. Both the phosphite 2a and the a rsenite derivative 3b have been examined by single-crystal X-ray analyses. Metal complexes (4-6) of the phosphites were prepared by reaction of the ph osphite with [PdCl2(cod]) (cod = 1,5-cyclooctadiene), [PdCl(eta (3)-C3H5)]( 2) and [Rh(CO)(2)(acac)] (acac = acetylacetonate), respectively, and exampl es of each are represented by X-ray structure determinations.