GRAPHICAL ABSTRACT
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Abstract
A novel sterically crowded triarylphosphine, [4-methyl-2,6-bis(2-methylphenyl)phenyl]bis(2,4,6-triisopropylphenyl)phosphine (1), was synthesized by the reaction of 4-methyl-2,6-bis(2-methylphenyl)phenylcopper(I) with chlorobis(2,4,6-triisopropylphenyl)phosphine. Triarylphosphine 1 exhibits a low inversion barrier, a reversible oxidation at low potential, and a UV absorption in long wavelength typical of sterically crowded triarylphosphines. The mCPBA oxidation of 1 gave the corresponding phosphine oxide of more crowded and rigid structure.