Hou Chen-Ying, Yang Chun, Tian Yin, Xie Ming-Sheng, Guo Hai-Ming
State Key Laboratory of Antiviral Drugs, Pingyuan Laboratory, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China.
State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
Org Lett. 2024 Aug 2;26(30):6390-6395. doi: 10.1021/acs.orglett.4c02156. Epub 2024 Jul 23.
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) 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) 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.
在手性抗衡阴离子的作用下，实现了镍（II）催化2-萘酚与β,γ-不饱和α-酮酯的傅克烷基化/环化反应中对映选择性的反转。以咪唑烷并吡咯并咪唑酮吡啶为配体，Ni(acac)为路易斯酸，以良好的产率（高达94%）和高对映选择性（高达99% ee）得到了多种萘并吡喃衍生物。在以Ni(OTf)为路易斯酸的情况下，以良好的产率得到了一系列手性萘并吡喃衍生物，且立体选择性得到了可控的转变。密度泛函理论计算表明，非手性抗衡阴离子调节了抗衡阴离子与配体的N-H以及2-萘酚的O-H之间的氢键相互作用。
