NMR study of iminophosphine oligomers by 31P, 15N and 31P, 13C heteronuclear shift correlation
NMR study of iminophosphine oligomers by 31P, 15N and 31P, 13C heteronuclear shift correlation
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通过 31P、15N 和 31P、13C 异核位移关联进行亚氨基膦低聚物的 NMR 研究
DOI：
10.1002/mrc.1260330110
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发表时间：
1995
影响因子：
2
通讯作者：
G. Schröder
中科院分区：
文献类型：
--
作者：
D. Gudat;M. Link;G. Schröder
基于具有15 N检测的非重聚焦INEPT脉冲序列的2D 31 P，15 N异频位移相关性被应用于氮杂二磷杂环丙烷1 - 5的15 N NMR研究，所述氮杂二磷杂环丙烷1 - 5通过亚氨基膦的[2 + 1]环加成反应形成，RP NR′。使用的脉冲序列允许在一个实验中一致地分配31 P和15 N NMR光谱;通过稍微修改，也可以确定一个或两个键上的许多31 P-15 N偶合常数的符号。通过与氮杂三磷杂环丁烷6（由ID 1H，15 N和31 P，15 N INEPT谱获得）的数据比较，表明了环的大小和构象效应对NMR参数的影响。31 P、13 C位移相关二维光谱进一步用于测量（包括符号确定）并分配1 - 5中1至3个键的31 P-13 C偶合常数。基于偶联信息和4a已知构象的分析，可以推导出非对映异构体4a和B的相对立体化学;此外，将1 - 3的31 P-13 C偶联数据与4a和B的数据进行比较，可以确定这些衍生物的构象，这是以前未知的。1 - 5的组成和立体化学的衍生信息提供了对亚氨基膦[2 + 1]环加成的机理细节的深入了解。
2D 31P, 15N heteronuclear shift correlation, based on a non‐refocused INEPT pulse sequence with 15N detection, was applied to a 15N NMR study of the azadiphosphiridines 1‐5 which are formed by [2 + 1] cycloaddition of iminophosphines, RPNR′. The pulse sequence used allowed consistent assignment of both the 31P and 15N NMR spectra in one experiment; by a slight modification, also the signs of numerous 31P‐15N coupling constants across one or two bonds could be determined. Comparison of the data with those of the azatriphosphetidine 6 (obtained from ID 1H,15N and 31P,15N INEPT spectra) showed the influence of the ring size and conformational effects on the NMR parameters. 31P,13C shift‐correlated 2D spectra were further used to measure (including sign determination) and assign 31P‐13C coupling constants across one to three bonds in 1‐5. Based on the analysis of the coupling information and the known conformation of 4a, the relative stereochemistry of the diastereomers 4a and b could be derived; further, the comparison of the 31P‐13C coupling data of 1‐3 with those of the 4a and b allowed the conformations of these derivatives, which were previously unknown, to be determined. The derived information of the constitution and stereochemistry of 1‐5 gives insight into mechanistic details of the iminophosphine [2 + 1] cycloaddition.