摘要
The design and synthesis of spirochroman-2-on-4,1'-indan-7'-ol(SCIOL)and its application for synthesizing chiral monophosphinite ligands are reported.The synthesis features a tandem double Friedel-Crafts reaction/lactonization to construct the spiro framework and the desired racemic SCiOL was obtained via 6 steps with a total yield of 44.5%.Using an inclusion resolution with N-benzylcinchonidinium chloride,the optical SCiOL could be obtained in good yields on a gram scale.The preliminary studies indicated that the corresponding chiral spiro monophosphinite ligands exhibit high catalytic activity and enantioselectivity(up to 94%ee)in the rhodium-catalyzed asymmetric hydrogenation of N-acetyl dehydroamino esters.These outcomes highlight the significant potential of SCiOLas a useful framework forthedevelopment of chiral spiro ligands.
基金
We thank the National Key R&D Program of China(2021YFA1500200)
the National Natural Science Foundation of China(92056105,92256303,22221002,and 22188101)
the Haihe Laboratory of Sustainable Chemical Transformations,the Fundamental Research Funds for the Central Universities,and the Frontiers Sciences Center for New Organic Matter at Nankai University(63181206)for financial support.
