Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Campus Sescelades, C/Marcellí Domingo, s/n 43007 Tarragona, Spain.
Chemistry. 2010 Mar 15;16(11):3434-40. doi: 10.1002/chem.200902777.
A highly modular library of readily available phosphite-oxazoline ligands L1-L21a-g was successfully applied in the asymmetric Pd-catalyzed Heck reactions of several substrates and triflates under thermal and microwave conditions. This ligand library contains three main ligand structures that have been designed by systematic modification of one of the most successful ligand families developed for this process. As well as studying the effect of these three ligand structures on the catalytic performance, we also evaluated the effect of modifying several ligand parameters in these ligand structures. The effectiveness of these ligands at transferring the chiral information into the product can be tuned by correctly choosing the ligand components. Both enantiomers of the Heck coupling products were obtained in excellent activities (conversion: >100% in 10 min), regioselectivities (>99%) and enantioselectivities (>99% ee). Under microwave-irradiation conditions, the reaction times were considerably shorter (full conversion was achieved in a few minutes) and the regio- and enantioselectivities were still excellent.
一个高度模块化的亚磷酸酯-噁唑啉配体 L1-L21a-g 库已经成功应用于多种底物和三氟甲磺酸酯的不对称 Pd 催化 Heck 反应，无论是在热条件下还是微波条件下。这个配体库包含了三种主要的配体结构，这些结构是通过对为这个过程开发的最成功的配体家族之一进行系统修饰而设计的。除了研究这三种配体结构对催化性能的影响外，我们还评估了在这些配体结构中修饰几个配体参数的效果。通过正确选择配体成分，可以调整这些配体将手性信息传递到产物中的有效性。Heck 偶联产物的对映异构体都具有优异的活性（转化率：在 10 分钟内超过 100%）、区域选择性（>99%）和对映选择性（>99%ee）。在微波辐射条件下，反应时间大大缩短（几分钟内即可完全转化），区域和对映选择性仍然优异。
