Novel Chiral Diamino-Oligothiophenes as Valuable Ligands in Pd-Catalyzed Allylic Alkylations. On the “Primary” Role of “Secondary” Interactions in Asymmetric Catalysis
作者:Vincenzo Giulio Albano、Marco Bandini、Manuela Melucci、Magda Monari、Fabio Piccinelli、Simona Tommasi、Achille Umani-Ronchi
DOI:10.1002/adsc.200505109
日期:2005.10
A new class of chiral C2-symmetrical diamino-oligothiophenes is described to be effective in catalyzing Pd-mediated asymmetric allylic alkylations in a highly enantioselective manner. The combination of experimental as well as crystallographic evidence revealed the key role played by sulfur-based heteroaromatic rings in the stereodiscriminating step of the procedure. In particular, unprecedented non-covalent
一种新型的手性C 2对称的二氨基-低聚噻吩被描述为以高对映选择性的方式有效催化Pd介导的不对称烯丙基烷基化反应。实验和晶体学证据的结合揭示了基于硫的杂芳族环在该方法的立体鉴别步骤中所起的关键作用。特别是,内部噻吩与金属中心之间空前的非共价二次相互作用被证明对于创造必要的立体化学环境至关重要,以确保出色的化学和光学收率。