convenient copper-catalyzed method has been developed to achieve direct ortho-C–H/N-H annulation to synthesize phenanthridinones with arynes. This method highlights an emerging strategy to transform inert C–H bonds into versatile functional groups in organic synthesis and provides a new way to synthesize phenanthridinone alkaloids efficiently.
Palladium-Catalyzed, <i>ortho</i>-Selective C–H Halogenation of Benzyl Nitriles, Aryl Weinreb Amides, and Anilides
作者:Riki Das、Manmohan Kapur
DOI:10.1021/acs.joc.6b02731
日期:2017.1.20
ortho-selective C–H halogenation methodology is reported herein. The highlight of the work is the highly selective C(sp2)–H functionalization of benzyl nitriles in the presence of activated C(sp3)–H bond, which results in good yields of the halogenated products with excellent regioselectivity. Along with benzyl nitriles, aryl Weinrebamides and anilides have been evaluated for the transformation using aprotic
Rhodium(I)-Catalyzed Aryl C–H Carboxylation of 2-Arylanilines with CO<sub>2</sub>
作者:Yuzhen Gao、Zhihua Cai、Shangda Li、Gang Li
DOI:10.1021/acs.orglett.9b01105
日期:2019.5.17
An unprecedented Rh(I)-catalyzed, amino-group-assisted C–H carboxylation of 2-arylanilines with CO2 under redox-neutral conditions has been developed. This reaction was promoted by a phosphine ligand with t-BuOK as the base and did not require the use of additional strong organometallic reagent. It enabled an efficient direct conversion of a broad range of 2-(hetero)arylanilines including electron-deficient
Electrochemical Formation of <i>N</i>-Acyloxy Amidyl Radicals and Their Application: Regioselective Intramolecular Amination of sp<sup>2</sup> and sp<sup>3</sup> C–H Bonds
Electrochemical generation of N-acyloxy amidyl radicals via an inner-sphereelectron-transferprocess is described for the first time. With NaBr as the catalyst and electrolyte, the in situ generated amidyl radicals undergo intramolecular C(sp2/sp3)–H aminations to give lactams with unprecedented regio- and chemoselectivities. Moreover, the synthetic utility of current method is demonstrated by the
Palladium-Catalyzed<i>β</i>-C−H Arylation of Ketones Using Amino Amide as a Transient Directing Group: Applications to Synthesis of Phenanthridinone Alkaloids
The direct arylation of aromatic and aliphatic ketones was carried out via palladium‐catalyzed inert C−H bond functionalization with 2‐amino‐N‐isopropyl‐acetamide as a new catalytic transient directing group. The reaction showed excellent functional group compatibility and site selectivity. We demonstrated that α‐amino amide forming N,N‐bidentate coordination with Pd catalyst is more favorable for