Development of a New Class of Chiral Phosphorus Ligands: P-Chirogenic Diaminophosphine Oxides. A Unique Source of Enantioselection in Pd-Catalyzed Asymmetric Construction of Quaternary Carbons
作者:Tetsuhiro Nemoto、Takamasa Masuda、Takayoshi Matsumoto、Yasumasa Hamada
DOI:10.1021/jo050800y
日期:2005.9.1
phosphorus compounds have been successfully applied to Pd-catalyzed asymmetric construction of tertiary and quaternary carbons. The actual ligand structure was the trivalent phosphorus species 17, which was generated in situ by BSA-induced P(V) to P(III) transformation of 6, the preligand. Detailed mechanistic studies, including asymmetric amplification and initial rate kinetics, revealed that complex 18
我们最近开发了新的一类手性磷配体:P-手性二氨基膦氧化物。这些五价磷化合物已成功地应用于Pd催化的叔碳和季碳的不对称结构。实际的配体结构是三价磷物质17,它是由BSA诱导的6(前配体)的P(V)到P(III)转化原位生成的。详细的力学研究,包括不对称扩增和初始速率动力学,揭示了复杂的18 [Pd- 17(1:2)络合物]是活性催化剂。还阐明了配体侧臂上氮原子的重要功能。不对称季碳结构中对映体的来源是由N-Zn配位介导的次级配体底物相互作用。