A robust synthesis of phenanthridines has been described via Pd(II)-catalyzed domino C(sp2)–H activation/N-arylation using oxime esters with aryl acyl peroxides in a highly regioselective manner. This protocol is compatible with acetophenone as well as benzophenone-derived oxime esters and allows modular construction of functionalized phenanthridines with wide tolerance of electronic functionality
This study reported the synthesis of 6-methylphenanthridines from 2-isocyanobiaryls using dimethylformamide (DMF) as a methyl carbon souce. The reactions were conducted in open-air atmosphere using electrochemical process at ambient temperature.
AbstractThe di‐tert butyl peroxide (DTBP)‐promoted sequential reaction of isonitriles is developed, leading to 6‐methylphenanthridine derivatives in moderate to excellent yields. DTBP served as both promoter and methyl source. The procedure proceeds through the addition of a methyl radical derived from the peroxide to the isonitrile followed by aromatic homolytic cyclization. It tolerates a series of functional groups, such as fluoro, chloro, acetyl, methoxycarbonyl, cyano and trifluoromethyl.magnified image
Pd-catalyzed assembly of phenanthridines from aryl ketone O-acetyloximes and arynes through C–H bond activation
作者:Chen-Yu Tang、Xin-Yan Wu、Feng Sha、Fei Zhang、Hao Li
DOI:10.1016/j.tetlet.2013.12.075
日期:2014.1
Pd-catalyzed annulation of aryne and aryl ketone O-acetyloxime via C-H bond activation was realized. Through the C-H bond activation/insertion/cyclization/elimination reaction sequence, phenanthridines are successfully constructed, providing an attractive strategy to approach substituted heterocycle without preactivation of starting materials. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.
Borsche, Justus Liebigs Annalen der Chemie, 1910, vol. 377, p. 119