Low-Temperature, Transition-Metal-Free Cross-Dehydrogenative Coupling Protocol for the Synthesis of 3,3-Disubstituted Oxindoles
作者:James R. Donald、Richard J. K. Taylor、Wade F. Petersen
DOI:10.1021/acs.joc.7b02085
日期:2017.10.20
strong, nonreversible base in these reactions has been found to effect a dramatic drop in reaction temperature (to room temperature) relative to the current state-of-the-art (>100 °C) procedure. When employing iodine as an “oxidant”, new evidence suggests that this transformation may occur via a transiently stable iodinated intermediate rather than by direct single-electron oxidation.
A novel copper(II)-mediated route for the conversion of anilides into 3,3-disubstituted-oxindoles is described which proceeds via a formal CâH, ArâH coupling process.
2-Electron-withdrawing-group-substituted 2-bromoanilides can be converted to the corresponding 3,3-disubstituted oxindoles with high efficiency under visible light irradiation by using fac-Ir(ppy)3 as the photoredox catalyst. This protocol is suitable for the synthesis of oxindoles with chloro and bromo atoms attached to the phenyl ring.
在可见光照射下,通过将2-抽电子基团取代的2-溴苯胺可以高效转化为相应的3,3-二取代的羟吲哚。 fac -Ir(ppy)3作为光氧化还原催化剂。该方案适用于合成具有连接在苯环上的氯和溴原子的羟吲哚。
Atom economical synthesis of oxindoles by metal-catalyzed intramolecular C–C bond formation under solvent-free and aerobic conditions
作者:Se In Son、Won Koo Lee、Jieun Choi、Hyun-Joon Ha
DOI:10.1039/c5gc00703h
日期:——
Diversely substituted oxindoles were obtained from atom economical direct C-C bondformation reactions of various substituted anilides and pyridinylamides with metal salts as catalysts including Cu2O, FeCl3, Fe2O3, TiO2, ZnO,...
Intramolecular Dehydrogenative Coupling of sp<sup>2</sup> C–H and sp<sup>3</sup> C–H Bonds: An Expeditious Route to 2-Oxindoles
作者:Santanu Ghosh、Subhadip De、Badrinath N. Kakde、Subhajit Bhunia、Amit Adhikary、Alakesh Bisai
DOI:10.1021/ol302767w
日期:2012.12.7
An intramolecular-dehydrogenative-coupling (IDC) using "transition-metal-free" oxidation conditions has been achieved to synthesize a variety of 2-oxindoles bearing an all-carbon quaternary stereogenic center at the benzylic position. The methodology involves a one-pot C-alkylation of beta-N-arylamido esters (3, 6) with alkyl halides using potassium tert-butoxide concomitant with a dehydrogenative coupling. A radical-mediated pathway has been tentatively proposed for the oxidative process.