Phen-2NO, a new <i>C</i><sub>2</sub>-symmetric rigid-featured tetradentate ligand, and its application in the asymmetric alkylation reaction of indoles
作者:Zi-Yue Chen、Ke-Lan Xu、Xi-Rui Wang、Pan Hu、Wei-Yan Jiang、Yi-Feng Dai、Li-Jun Peng、Xiong-Li Liu
DOI:10.1039/d4nj00088a
日期:2024.4.15
great coordination ability with various ions, the development of new chiral phen ligands is in great demand in asymmetric catalysis. Herein, we rationally designed and developed an entirely new class of C2-symmetric rigid-featured chiral phen ligands that provide the N,N,O,O-tetradentate coordination of the phen moiety and two additional N,N-dioxides. The chiral ligands, termed Phen-2NO ligands, incorporate
由于菲咯啉(phen)与各种离子具有很强的配位能力,因此不对称催化中迫切需要开发新型手性phen配体。在此,我们合理地设计和开发了一类全新的C 2 -对称刚性特征手性phen配体,其提供了phen部分的N , N , O , O -四齿配位和两个额外的N , N -二氧化物。手性配体,称为 Phen-2NO 配体,结合了 phen 骨架和基于吡咯并咪唑啉酮的N-氧化物部分的优点,并且可以通过在酰胺芳环中引入取代基来轻松调整其电子和空间性质。团体。这些配体在 Ni( II ) 催化的吲哚与 β,γ-不饱和 α-酮酯的不对称 Michael 型 Friedel-Crafts 烷基化反应中表现出优异的性能。在温和条件下,多种底物均获得优异的产率(高达 93%)和高对映选择性(高达 99% ee)。这些结果证明了 Phen-2NO 配体作为有效的手性 phen 配体的巨大潜力。