- 作者: 施雲娥 ; 劉宜芳 ; 王之士 等
- 作者服務機構: 中央研究院化學研究所
- 中文摘要: X-ray structures of trans-2-dimethylamino-5-phenyl-2H-1,3,2-oxazaphosphorinane-2-oxide, 5b, and trans-2-dimethylamino-6-phenyl-2H-1,3,2-oxazaphosphorinane-2-oxide, 6c, have been determined. These two compounds have been prepared in a straightforward manner by a reaction of cyclization of Me/sub 2/NP(O)Cl/sub 2/ with the corresponding 3-amino-2-phenylpropanol and 3-amino-1-phenylpropanol, respectively, to produce(5b,6b) and (5c,6c), and were separated into pure forms by chromatography. Crystal data of 5b: space group P/sub ccn/, a=10.675(5), b=31.685(9), c=7.217(3).ANG., R=0.065 for 1040 reflections. Crystal data of 6c: space group P-1, a=9.803(6), b=12.455(5), c=12.690(2).ANG., .alpha.=114.11(2),.beta.=80.88(2), .gamma.=111.64(4).degree., R=0.035 for 3534 reflections. For the pair 5b and 6b, the slowly-migrating 5b is trans (Ph and P=O group trans) with the configuration of 2RS, 5RS; hence 6b is the cis isomer. For the pair 5c and 6c, the slowly migrating 6c is trans with the configuration of 2RS, 6SR; hence 5c is the cis isomer. In both X-ray structures the 1,3,2-oxazaphosphorinane rings are chair-like with the P-end essentially flattened. With a conformationally demanding 5-phenyl substituent, 5b has an axial Me/sub 2/N whereas with also a conformationally demanding 6-phenyl substituent, 6c has an equatorial Me/sub 2/N. For 6c, the exocyclic P-N bond has partial double bond character: the geometry about exocyclic N is planar. On the other hand, for 5b, the geometry about exocyclic N deviates considerably from planarity, the sum of the angles around N being 343.3.degree.. In the crystalline state, the two crystallographically independent molecules of 6c are linked together in a hydrogen-bonded system involving the water molecule.
- 英文摘要: --
- 中文關鍵字: X-Ray Structure Analysis; 1,3,2-Oxazaphosphorinane Ring System; Phosphorus; Axial Substitution; Equatorial Substitution
- 英文關鍵字: X-射線結構分析;磷;軸取代;赤道取代