Meyers A I, Nguyen T, Stoianova D, Sreerama N, Woody R W, Koslowski A, Fleischhauer J
Department of Chemistry, Colorado State University, Fort Collins 80523, USA.
Chirality. 1997;9(5-6):431-4. doi: 10.1002/(SICI)1520-636X(1997)9:5/6<431::AID-CHIR6>3.0.CO;2-8.
By use of an asymmetric Ullmann coupling involving chiral naphthalene oxazolines 1, the title compounds were prepared in good yields and with high diastereoselectivity. Hydrolysis of the binaphthyl oxazolines 2 led to the di-aldehydes 5, which were transformed into the azepine derivative, 6. The latter was treated with the appropriate phosphoryl halide to access the chiral HMPA systems 7 and 9. The CD spectra of the chiral azepine 6 and the chiral phosphoramides 7 and 9 were measured and showed a strong positive CD couplet near 225 nm, consistent with the P axial chirality (S configuration). Semi-empirical CNDO/S molecular orbital calculations of the CD spectrum of 6 satisfactorily reproduced the major features of the observed spectrum.
通过使用涉及手性萘恶唑啉1的不对称乌尔曼偶联反应，以良好的产率和高非对映选择性制备了标题化合物。联萘恶唑啉2的水解产生二醛5，其被转化为氮杂环庚三烯衍生物6。后者用适当的磷酰卤处理以得到手性HMPA体系7和9。对手性氮杂环庚三烯6以及手性磷酰胺7和9的圆二色光谱进行了测量，结果表明在225 nm附近有一个强的正圆二色偶合峰，这与P轴手性（S构型）一致。对6的圆二色光谱进行的半经验CNDO/S分子轨道计算令人满意地再现了观察到的光谱的主要特征。
