136145-00-1Relevant articles and documents
CONFORMATIONS OF SATURATED SIX-MEMBERED-RING PHOSPHORUS HETEROCYCLES. SYNTHESES AND X-RAY CRYSTAL STRUCTURES OF THREE 2-ANILINO-2-OXO-5,5-DIMETHYL-1,3,2-OXAZAPHOSPHORINANES
Bentrude, Wesley G.,Setzer, William N.,Newton, M. Gary,Meehan, Edward J.,Ramli, Emmanuel,et al.
, p. 25 - 35 (2007/10/02)
Single-crystal X-ray structural determinations have been made on 2-anilino-2-oxo-5,5-dimethyl-1,3,2-oxazaphosphorinane, 1; 2-(4-fluoroanilino)-2-oxo-5,5-dimethyl-1,3,2-oxazaphosphorinane, 2; and 2-(4-dimethylaminoanilino)-2-oxo-5,5-dimethyl-1,3,2-oxazaphosphorinane, 3.Compounds 1 and 2 are isostructural and crystallize in the monoclinic space group P21/c with four molecules per unit cell.The cell dimensions for 1 are: a = 12.234(4) Angstroem, b = 8.891(3) Angstroem, c = 12.152(4) Angstroem, and B = 110.77(4) deg.The cell dimensions for 2 are: a = 12.505(1) Angstroem, b = 8.919(1) Angstroem, c = 12.211(1) Angstroem, and B = 109.14(1) deg.Compound 3 crystallizes in the monoclinic space group P21/n with four molecules per unit cell of dimensions a = 6.321(2) Angstroem, b = 19.963(3) Angstroem, c = 12.236(2) Angstroem, and B = 104.89(4) deg.Full-matrix least-squares refinement for each of the structures led to conventional R factors of 5.1percent for 1, 4.9percent for 2, and 9.5percent for 3.The conformation adopted by 1 and 2 is the chair conformation with the anilino substituent axial.Compound 3 adopts the alternative chair conformation with an equatorially disposed anilino substituent.Structural variations are found which can be attributed to the operation of exo and endo anomeric effects.
