A novel, C-2-symmetric, chiral bis-cyclosulfinamide-olefin tridentate ligand in Rh-catalyzed asymmetric 1,4-additions

作者：Zhang, Li; Tan, Mingchao; Zhou, Lihong; Zeng, Qingle^*

来源：Tetrahedron Letters, 2018, 59(29): 2778-2783.

DOI：10.1016/j.tetlet.2018.06.008

• Asymmetric catalysis
• Chiral tridentate ligand
• Bis-cyclosulfinamide
• 1-Oxo-2,3-dihydro-1,2-benzisothiazole
• Asymmetric 1,4-addition

A C-2-symmetric, chiral bis-cyclosulfinamide-olefin ligand composed of two 1-oxo-2,3-dihydro-1,2-benzisothiazole moieties with rigid skeletons and a conformationally flexible butenylene chain is disclosed for the first time. HRMS and H-1 NMR analyses verify that the in situ-generated complex of the ligand and [Rh(C2H4)(2)Cl](2) possesses a rhodium (I) center coordinated to the tridentate ligand via two sulfinyl moieties and a CdbndC bond. The chiral ligand provided extremely high enantioselectivity (up to >99% ee) in the Rh-catalyzed asymmetric 1,4-additions of arylboronic acids to cyclohexenone and cyclopentenone. The tridentate ligand gave much higher enantioselectivity than the analogous chiral bidentate ligands.

• 出版日期2018-7-18
• 单位成都理工大学; 地质灾害防治与地质环境保护国家重点实验室