An Imidazoline- Aminophenol ( IAP) Nickel Catalyst: Structure and Catalytic Activity in the Enantioselective 1,4-Addition of 3%26apos;- Indolyl-3-Oxindoles to Nitroethylene

作者：Awata Atsuko; Wasai Makiko; Masu Hyuma; Kado Sayaka; Arai Takayoshi^*

来源：Chemistry - A European Journal, 2014, 20(9): 2470-2477.

DOI：10.1002/chem.201304456

• asymmetric catalysis
• indole 1
• 4-addition
• nickel
• tridentate ligands

The structure of a nickel complex of imidazoline-aminophenol (IAP) prepared from IAP with Ni(OAc)(2) was elucidated as cis-bis(imidazolineaminophenoxide) [Ni(IAP)(2)]. The [Ni(IAP)(2)] complex smoothly promoted catalytic asymmetric 1,4-addition of 3-indolyl-3-oxindole to nitroethylene to provide chiral mixed 3,3-bisindoles with high enantioselectivities. Mechanistic studies using ESI-MS analyses suggest that one IAP ligand dissociated from [Ni(IAP)(2)] to generate the Ni-enolate of 3-indolyl-3-oxindole. From the optically active 3,3-mixed indole adduct, biologically important 3-indolyl-3-pyrrolidinoindoline was successfully synthesized in a three-step reaction sequence.

• 出版日期2014-2-24