Gold as Catalyst for the Hydroarylation and Domino Hydroarylation/N1–C4 Cleavage of β-Lactam-Tethered Allenyl Indoles
摘要:
Gold-catalyzed hydroarylation reaction of beta-lactam-tethered allenyl indoles gives azeto-oxepino[4,5-b]-indol-2-ones, tetrahydroazeto-azocino[3,4-b]indol-2-ones, and hexahydroazeto-azepino[3,4-b]indol-2-ones with very high levels of stereo, and regioselectivity, the 7-exo and 8-endo carbocyclization modes by attack of the indole group toward either the internal or the terminal allene carbon, respectively, being favored. Hydroarylation across the central carbon of the allene moiety has not been detected. The controlled gold-catalyzed annulations allowed the formation of fused beta-lactams without harming the sensitive four-membered heterocycle. Besides, a novel gold-catalyzed domino process, namely, the allenic hydroarylation/N1-C4 beta-lactam bond breakage to afford dihydro-oxepino[4,5-b]indole-4-carboxamides, has been discovered.
Catalyst- and solvent-free efficient access to <i>N</i>-alkylated amines <i>via</i> reductive amination using HBpin
作者:Vipin K. Pandey、Somnath Bauri、Arnab Rit
DOI:10.1039/d0ob00740d
日期:——
conditions for the synthesis of structurallydiverse secondary amines has been uncovered. This one-pot protocol works efficiently at room temperature and is compatible with a wide range of sterically and electronically diversealdehydes and primary amines. Notably, this simple process offers scalability, excellent functional group tolerance, chemoselectivity, and is also effective at the synthesis of biologically