作者:G.V. Shustov、A.B. Zolotoi、N.L. Zaichenko、O.A. Dyachenko、L.O. Atovmyan、R.G. Kostyanovsky
DOI:10.1016/s0040-4020(01)88458-1
日期:1984.1
A second-kind asymmetric transformation involving N-atom inversion has been observed at 20° for 1(S) - α - carboxyethyl - 3,3 - bis(trifluoromethyl)diaziridine 1 and its methyl ester 2. X-Ray data for the diastereomer (1S, 2S, α-S), 1A (which is thermodynamically preferred in the crystalline phase), 1H NMR spectra of ethyl ester 3-15N(1) and 3-15N(2), CD spectra of 1A,B, 2A,B, potassium salt 4A,B and
1(S)-α-羧乙基-3,3-双(三氟甲基)二氮丙啶1及其甲酯2在20°观察到涉及N原子倒置的第二种不对称转化。对于非对映体的X射线数据(1S,2S,α-S),1A(其在结晶相在热力学上优选的),1乙基酯的1 H NMR谱3 - 15 N(1)和3- 15 N(2 ),的CD光谱1A,B,图2A,B,钾盐4A,B和半经验计算(MINDO / 3和INDO)为1A,表明非对映异构体A的结晶立体性是由于非对映异构体(1R,2R,α-S),1B的晶格能量较高,因为电荷补偿受阻以及CF 3的阻碍分子间的氢键。根据半经验计算,由于超共轭和CF 3-基团的诱导作用,3,3-双(三氟甲基)-二氮丙啶(TFD)对el w轨道能量作用和CN键去极化的稳定性。与3,3-二甲基类似物相比,这些基团的空间效应是TFD的低构型稳定性的原因。