Synthesis of 2,5-Disubstituted Oxazoles and Oxazolines Catalyzed by Ruthenium(II) Porphyrin and Simple Copper Salts
作者:Chuan Long Zhong、Bo Yang Tang、Ping Yin、Yue Chen、Ling He
DOI:10.1021/jo202663n
日期:2012.5.4
A novel and moderate synthesis of 2,5-disubstituted oxazoles and oxazolines involving ruthenium(II) porphyrin copper chloride catalyzed cyclization was developed. These reactions using readily available benzene carboxylic acids and phenylethenes or phenylacetylenes are performed under mild conditions. The reactions proceed in series, giving rise to the formation of an intermolecular C-N bond and an intramolecular C-O bond, which yield oxazole or oxazoline derivatives simultaneously.
SIEGRIST A. E.; MEYER H. R.; GASSMANN P.; MOSS S., HELV. CHIM. ACTA, 1980, 63, NO 5, 1311-1334
作者:SIEGRIST A. E.、 MEYER H. R.、 GASSMANN P.、 MOSS S.
DOI:——
日期:——
Oxazolinyl-Assisted C–H Amidation by Cobalt(III) Catalysis
作者:Ruhuai Mei、Joachim Loup、Lutz Ackermann
DOI:10.1021/acscatal.5b02661
日期:2016.2.5
Cobalt-catalyzed C–H activation by means of oxazolinyl assistance set the stage for versatile direct amidations with ample substrate scope. Thus, a high-valent cobalt(III) catalyst enabled C–H amidations with excellent levels of positional and chemo-selectivities. Mechanistic studies provided strong support for a kinetically relevant C–H functionalization.
The annulation reactions of benzoamidyl radicals with alkenes were realized under visible light irradiation with fac-Ir(ppy)3 as catalyst and N-aminopyridinium salts as benzoamidyl radical precursors. The reaction can deliver two distinct types of products: in the case of vinyl arenes, [3 + 2] annulation product dihydrooxazoles were yielded exclusively; when alkyl-substituted alkenes were used, on the