Gong Chen Lab @ Nankai / 南开大学陈弓课题组
恭喜博士生童华绒的文章被ACS Catalysis接受

恭喜博士生童华绒的文章被ACS Catalysis接受,祝贺!

https://pubs.acs.org/doi/pdf/10.1021/acscatal.8b03654

Palladium-catalyzed enantioselective C(sp3)-H functionalization could provide valuable reactions for organic synthesis. While significant progress has been made on monodentate directing group (DG)-mediated enantioselective C-H func-tionalization using amino acid or N-heterocycle-based chiral ligands, methods for enantioselective C(sp3)-H functionaliza-tion mediated by bidentate DGs have lagged far behind. 8-Aminoquinoline (AQ) is a powerful N,N-bidentate auxiliary for Pd-catalyzed C(sp3)-H functionalization reactions. The bidentate binding mode of AQ can stabilize high valent Pd inter-mediates, enabling challenging transformations through a PdII/IV catalytic manifold. Recently, Duan reported an enanti-oselective Pd-catalyzed AQ-directed benzylic C-H arylation of 3-arylpropanamides using PdII catalyst and BINOL phos-phoramide (PV) ligand. Herein, we report a protocol for Pd-catalyzed AQ-mediated enantioselective benzylic C-H aryla-tion of 3-arylpropanamides using Pd0 catalyst and BINOL-phosphoramidite (PIII) ligand. These reactions give good to high yield and improved enantioselectivity (up to 95% ee). Mechanistic studies indicate the reactions proceed via a Pd0/II cata-lytic cycle, unprecedented for AQ-directed reactions. DFT calculations suggest that both phosphoramidite ligand and cesium carbonate base are involved in the enantio-determining C-H palladation step, and that the AQ directing group converts between binding modes to accommodate the C-H palladation and reductive elimination steps.

Article classification: 新闻资讯
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