Relative and absolute configurations of dissolved molecules by NMR-spectroscopy in orienting media

这个研究小组的目的是DFG-Forschergruppe是一种基于各向异性NMR参数的计算机辅助NMR光谱测定天然产物和其他有机化合物的相对和绝对构型的通用方法（残余偶极耦合，RDC和残余化学位移各向异性，RCSA）以及非手性和手性相对和绝对构型定向介质的发展和应用。多年来，NOE或3 J标量耦合常数等参数已被应用于溶解分子的构象分析，这些分子在大多数情况下是具有确定的立体中心的生物聚合物。由于缺乏对任意化合物的J-耦合的参数化，应用没有这种限制的附加结构约束，如RDC，是迫切需要的。此外，与基于NOE/J偶联的结构解析不同，RDC对标量或NOE连接性中的断裂不敏感。这在未知立体单元的构型分配的上下文中是特别重要的，特别是如果它们彼此远离。为了实现这一目标，并满足需要的多对齐数据集，新的对齐介质（非手性和手性）以及新的方法的测量，解释和预测的RDC的必须开发。 下文将简要介绍研究单位在实现这些目标方面取得的进展。在此基础上，对今后的研究方向进行了讨论。第2节和各提案在其本国背景下简要介绍了结果。

The aim of this research unit (DFG-Forschergruppe) is the development of a generally applicable and versatile method for the computer-assisted NMR-spectroscopic determination of the relative and absolute configuration of natural products and other organic compounds based on anisotropic NMR-parameters (residual dipolar couplings, RDCs and residual chemical shift anisotropy, RCSA) and the development and application of achiral and chiral orienting media for the relative and absolute configuration, respectively. Since many years parameters like the NOE or the 3J scalar coupling constants have been applied for the conformational analysis of dissolved molecules being biopolymers with defined stereogenic centers in most cases. Due to the lacking parametrization of J-couplings for arbitray compounds, the application of additional structural restraints without this limitation, such as RDC's, is an urgent necessity. Moreover, unlike the NOE/J-coupling based structural elucidation, RDC's are not sensitive to breaks in the scalar or NOE connectivities. This is of special importance in the context of configurational assignments of unknown stereogenic units, particularly if they are far away from each other. To achieve this goal and to meet the need for multiple-alignment data sets, new alignment media (achiral and chiral) as well as new methods for the measurement, interpretation and prediction of RDC's have to be developed. In the following, the progress of the research unit with respect to these goals will be described briefly. After this survey the future research directions will be discussed. Results are described briefly in section 2 and in the individual proposals in their native context.