关键词: 低价钛, (3-氧代-1, 3-二芳基)丙基丙二腈, 2-氨基-3-氰基-1, 4-二芳基-2-环戊烯-1-醇, 晶体结构, 立体构型

Abstract: This paper reports the reactions of low-valent titanium reagent(TiCl₄-Zn system) with (3-oxo-1,3-diaryl) propylpropanedinitrile. It is found that the low-valent titanium can promote a novel cyclization of (3-oxo-1,3-diaryl)propylpropanedinitrile to give 2-cyano-3,5-diary-1-aminocyclopentene, trans and cis 2-amino-3-cyano-1,4-diary-2-cyclopentene-1-ol. The latter's configurations are determinated by X-ray diffraction analysis.The crystal of compound 3c is triclinic with space group P1, a =1.0389(4) nm, b =1.2292(4) nm, c = 0.8027(3) nm, 7 α = 93.29(3)°, r =113.32(3)°, V =0.9362(6) nm³, Z =2, D_c=1.1939 g/cm³, μ =0.77 cm^-1, F (000)= 360, and find R =0.067 and R_w=0.057 for 1308 reflections ( I >3 σ ( I )). The crystal of compound 4a is orthorhombic with space group Pbcn, a = 1.3370(5) nm, b = 1.0481(5) nm, c =2.3350(6) nm, V =3.272(3) nm³, Z =8, D_c= 1.262 g/cm³, μ = 2.36 cm^-1, F (000)=1296, and find R =0.043 and R_w=0.049 for 1426 reflections ( I >3 σ ( I )). A possible reaction mechanism is proposed in this paper.

Key words: Low valent titanium, (3-Oxo-1,3 diaryl)propylpropanedinitrile, 2-Amino-3-cyano-1,4 diaryl-2-cyclopentene-1-ol, Crystal structure, Stereoconfiguration