191548-35-3Relevant academic research and scientific papers
Competitive [4+2] cycloadditions in equimolar mixtures of 1-arylphosphole oxides
Keglevich,Chuluunbaatar,Dajka,Namkhainyambuu,Ludanyi,Toke
, p. 633 - 635 (2007/10/03)
Four different [4+2] cycloadditions were observed to take place in the equimolar mixtures of two different arylphosphole oxides 2a + 2b or 2b + 2c. In addition to the phosphole oxide dimers 3a-a and 3b-b, or 3b-b and 3c-c, the crossed cycloadducts 3a-b and 3b-a, or 3b-c and 3c-b were also formed in considerable portions.
Phospholes with reduced pyramidal character from steric crowding III NMR and X-ray diffraction studies on 1-( 2,4,6-tri-isopropylphenyl)-3-methylphosphole
Keglevich, Gyoergy,Quin, Louis D.,Boecskei, Zsolt,Keserue, Gyoergy M.,Kalgutkar, Rajdeep,Lahti, Paul M.
, p. 109 - 116 (2007/10/03)
The 2,4,6-tri-isopropylphenyl substituent was placed on the phosphorus of a phosphole to reduce the pyramidal character. That this was accomplished was revealed by single crystal X-ray diffraction analysis; with respect to the plane of C2-P-C5 in the phosphole ring, the ipso carbon of the benzene ring was deflected by only 58.0°, whereas the deflection is 66.9° in the uncrowded 1-benzylphosphole. This proves that the concept of reducing the pyramidal character (with the goal of increasing the electron delocalization) through steric crowding can be realized. In the crystal the two rings are in orthogonal planes, but this relation is not retained in solution; NMR studies show that the two edges of the benzene ring, as well as the 2,6-isopropyl groups, are identical.
