Achiral Counteranion-Induced Reversal of Enantioselectivity in Ni(II)-Catalyzed Friedel–Crafts Alkylation/Annulation of 2-Naphthols

作者：Chen-Ying Hou, Chun Yang, Tian Yin, Ming‐Sheng Xie, Hai‐Ming Guo · 发表于：Organic Letters · 年份：2024 · DOI：10.1021/acs.orglett.4c02156 · 被引用次数：18 · 研究领域：Asymmetric Hydrogenation and Catalysis、Asymmetric Synthesis and Catalysis、Axial and Atropisomeric Chirality Synthesis

An achiral counteranion-induced reversal of enantioselectivity in Ni(II)-catalyzed Friedel–Crafts alkylation/annulation of 2-naphthols with β,γ-unsaturated α-keto esters was achieved. Using imidazolidine pyrroloimidazolone pyridine as the ligand and Ni(acac) 2 as the Lewis acid, diverse naphthopyran derivatives were obtained in good yields (up to 94% yield) and high enantioselectivities (up to 99% ee). In the presence of Ni(OTf) 2 as the Lewis acid, a series of chiral naphthopyran derivatives were obtained in good yields and with a controlled switch in stereoselectivity. DFT calculations reveal that the achiral counteranions regulate H-bonding interactions between counteranions with the N–H of the ligand and the O–H of 2-naphthol.