Reaction of a sterically crowded triarylphosphine with iodine in the presence of oxygen

<p>Reaction of tris(2,4,6-triisopropylphenyl)phosphine with iodine in air afforded a phosphonium triiodide resulting from the oxidation to the radical cation followed by the reaction with a molecular oxygen and the cyclization with the ortho-isopropyl group.</p

Synthesis and properties of a sterically crowded triarylphosphine bearing an ester group

<p>A sterically crowded triarylphosphine bearing an ester group, (4-ethoxycarbonyl-2,6-diisopropylphenyl)bis(2,4,6-triisopropylphenyl)phosphine, was synthesized by the lithiation of the corresponding (bromoaryl)phosphine followed by the reaction with excess diethyl carbonate. The ester was obtained as lemon yellow crystals and exhibits the blueshifted UV-Vis absorption and fluorescence as compared with the orange-colored corresponding aldehyde and ketone. The effect of the substitution of an ester group on the photophysical and redox properties of the sterically crowded triarylphosphine is discussed, and the properties of the sterically crowded triarylphosphines bearing an aldehyde, a ketone, and an ester groups are briefly reviewed.</p

Synthesis, Structure, and Properties of [4-Methyl-2,6-Bis(2-Methylphenyl)Phenyl]Bis(2,4,6-Triisopropylphenyl)Phosphine

<div><p>GRAPHICAL ABSTRACT</p><p></p></div

Synthesis and Structure of Sterically Crowded Triarylphosphine Bearing 4-Bromo-2,6-Bis(4-<i>tert</i>-Butylphenyl)Phenyl Group

<div><p></p><p>A novel sterically crowded triarylphosphine bearing a 2,6-diaryl-4-bromophenyl group, [4-bromo-2,6-bis(4-<i>tert</i>-butylphenyl)phenyl]bis(2,4,6-triisopropylphenyl)phosphine (<b>1</b>), was synthesized. The X-ray crystallography revealed that the bond angles and lengths around the phosphorus atom (110.9°, 1.846 Å) are comparable to those of tris(2,4,6-triisopropylphenyl)phosphine and its derivatives. Triarylphosphine <b>1</b> is reversibly oxidized to the radical cation at the potential close to that of the typical sterically crowded (bromoaryl)phosphine, (4-bromo-2,6-diisopropylphenyl)bis(2,4,6-triisopropylphenyl)phosphine, and exhibits the UV absorption at long wavelength (<i>λ</i>_max 332 nm) characteristic of the sterically crowded triarylphosphines. Thus, triarylphosphine <b>1</b> can be regarded to be a promising candidate for the key synthetic intermediate or building block to the functional molecules bearing sterically crowded triarylphosphine moieties.</p></div