Novel carbohydrate olefin hybrid ligands in rhodium catalyzed reactions: Challenging substrates in 1,4-additions

在第一个资助期内，基于手性库中的碳水化合物制备了一些新的具有烯烃和亚磷酸酯部分的手性杂二齿配体。这些配体是很容易获得的假对映异构体杂合配体，它们被成功地用于铑催化的不对称1，4-加成反应。在这里，我们计划详细研究具有挑战性的亲核试剂，如杂芳基硼酸酯的不对称催化1，4-加成，通过NMR光谱，以确定和解决出现的问题。此外，有问题的亲电体，如具有环外受体取代基的环烯烃，例如。G.环烯烃-1-腈将用于反应中。在此基础上合成了各种药用药物，如。G.（-）-帕罗西汀。此外，迄今为止前所未有的不对称催化1，4-加成在C2-取代的环戊烯将被用于合成类固醇激素equilenine研究。1，3-二恶英-4-酮的1，4-加成是未知的，将作为3-羟基羰基化合物的新途径进行审查。最后，将结合这两个项目进行定向试验。

In the first funding period a number of new chiral heterobidendate ligands with an alkene and a phosphite moiety were prepared based on carbohydrates from the chiral pool. These ligands are well accessible, pseudo-enatiomeric hybrid ligands, which were successfully employed in asymmetric rhodium-catalyzed 1,4-additions. Here we plan to investigate in detail asymmetric catalytic 1,4-additions with challenging nucleophiles such as heteroarylboronates by NMR spectroscopy in order to identify and solve occurring problems. Further, problematic electrophiles such as cycloalkenes with an exocyclic acceptor substituent, e. g. cycloalkene-1-carbonitriles, will be employed in the reaction. On this basis the synthesis of various medicinal drugs, e. g. (-)-paroxenine, will be achieved. In addition, the so far unprecedented asymmetric catalytic 1,4-addition at C2-substituted cyclopentenes will be investigated for synthesizing the steroid hormone equilenine. 1,4-Additions at 1,3-dioxin-4-one are unknown and will be scrutinized as a new access to 3-hydroxycarbonyl compounds. Finally orienting experiments with a combination of the two project lines will be undertaken.