Tartaric Acid, off the Shelf Building Block for the Construction of New Chiral Transition Metal Complexes and Molecular Cages/Wires and their Further Use in Asymmetric Catalysis

过去，在有机配体的金属络合领域已经取得了许多里程碑，导致了高对映选择性催化剂或具有有趣性质的超分子组装。在这项提议中，我们设想从价格较低的手性酒石酸开始合成新的手性过渡金属络合物。因此，需要合成二醇、二胺和氨基醇等手性前体，最近，相关化学已经在我们的实验室得到了很好的建立。这些手性构建基块与醛、腈或羧酸缩合，然后与各种过渡金属络合，得到新的Salen、双恶唑啉或酚基恶唑啉配合物。通过改变手性单元或缩合产物的取代模式，可以很容易地对这些过渡金属体系进行调节，以优化所给出的对映选择性。在我们的实验室中，很少有配合物催化的反应，即烯烃的对映选择性环氧化和环丙化反应。具有有趣的不对称诱导的过渡金属络合物也应该催化广泛的反应，例如：烯丙基乙酸酯的亲核取代，外消旋环氧化物的水解动力学拆分，Diels-Alder等。此外，这类过渡金属络合物由于其众多的络合位置，也应该会导致新的超分子聚集体。二元醇或二胺与1，3-二酮类化合物缩合应得到手性双-1，3-二酮配体。这些化合物由于其额外的杂原子给体，是设计金属冠醚和密码的有希望的候选者。这些络合物应该得到对映体纯的螺旋分子笼子或手性的一维氧桥金属弦。同样，AS催化剂在不对称催化中的潜力也将被研究。此外，在乙醚官能团上引入辅助络合单元将导致一类新的不对称催化催化剂，它是通过自组装产生的。

In the past, many milestones have been attained in the field of metal complexation by organic ligands leading either to highly enantioselective catalysts or to supramolecular assemblies with interesting properties. In this proposal we envisage the synthesis of new chiral transition metal complexes starting from the less expensive chiron tartaric acid. Chiral precursors like diols, diamines, and aminoalcohols therefore need to be synthesised, and recently, the related chemistry has been well established in our laboratories. The condensation of these chiral building blocks with aldehydes, nitriles, or carboxylic acids followed by complexation with various transition metals leads to new salen, bi(oxazoline), or phenolic oxazoline complexes. The tuning of these transition metal systems for optimising the enantioselectivity given by is easily performed by modifying the substitution pattern of the chiral unit or of the condensation product. Few reactions catalysed by complexes were already carried out in our laboratories viz., enantioselective epoxidation and cyclopropanation of olefins. A broad spectrum of reactions should also be catalysed by such transition metal complexes with interesting asymmetric induction, for example: the nucleophilic substitution of allylic acetates, the hydrolytic kinetic resolution of racemic epoxides, Diels-Alder, et cetera. In addition, such transition metal complexes, due to their numerous complexation sites, should also lead to new supramolecular aggregates. The condensation of diols or diamines with 1,3-diketone equivalents should give chiral bis-1,3-diketone ligands. These compounds, owing to their extra heteroatom donors, are promising candidates for the design of metallacoronands and cryptates. These complexes should lead to enantiomerically pure, helical molecular cages or to chiral, one-dimensional oxo-bridged metal strings. Equally, the potential of as catalysts for asymmetric catalysis will be studied. Furthermore, the introduction of supplementary complexation units at the ether functions should lead to a new class of catalysts for asymmetric catalysis, generated by self-assembly.