Absolute configuration of tert-butyl-1-(2-methylnaphthyl)phosphine oxide.
Absolute configuration of tert-butyl-1-(2-methylnaphthyl)phosphine oxide.
复制标题
叔丁基-1-(2-甲基萘基)氧化膦的绝对构型。
DOI：
10.1021/jo025908h
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Zygo,Krystyna
中科院分区：
文献类型：
--
作者：
Wang,Feng;Wang,Yan;Polavarapu,PrasadL;Li,Tingyu;Drabowicz,Józef;Pietrusiewicz,KMichal;Zygo,Krystyna
用自制的高效液相色谱柱和分析梯度系统分离了叔丁基-1-（2-甲基萘基）氧化膦对映体。在CD 2Cl 2和CH 2Cl 2溶液中，在2000 - 900 cm-1区域测量了两种对映体的振动吸收光谱和圆二色光谱。采用B3 LYP方法，在6- 31 G * 基组下，计算得到了（S）-叔丁基-1-（2-甲基萘基）氧化膦的全弛豫势能面，结果表明该化合物有两种稳定的构象，其布居比为1：2：1.用B3 LYP泛函在6- 31 G * 基组下预测了这两种构象的振动吸收光谱和VCD谱。计算光谱与实验光谱的比较表明，（+）-叔丁基-1-（2-甲基萘基）氧化膦为（S）-构型。这一归属得到了从头计算预测的最稳定构象的正旋光度与（S）-构型和叔丁基化学位移的非等价意义的支持，在（+）-（S）-扁桃酸作为手性溶剂的存在下，在1H NMR谱中观察到该对映体。
The enantiomers oftert-butyl-1-(2-methylnaphthyl)phosphine oxide1have been separated using a homemade HPLC column and an analytical gradient system. Vibrational absorption and circular dichroism spectra for both enantiomers have been measured in CD2Cl2and CH2Cl2solutions in the 2000−900 cm-1region. The fully relaxed potential energy surface of (S)-tert-butyl-1-(2-methylnaphthyl)phosphine oxide, obtained using the B3LYP functional with a 6-31G* basis set, indicated two stable conformers with their populations in a ∼2:1 ratio. The vibrational absorption and VCD spectra are predicted for these two conformers using the B3LYP functional with a 6-31G* basis set. The comparison of predicted and experimental spectra indicated that (+)-tert-butyl-1-(2-methylnaphthyl)phosphine oxide is in the (S)-configuration. This assignment is supported by the ab initio prediction of positive optical rotation for the most stable conformer with an (S)-configuration and the nonequivalence sense of thetert-butyl group chemical shift observed in the1H NMR spectrum of this enantiomer measured in the presence of (+)-(S)-mandelic acid as a chiral solvating agent.