Reductive cyclization of halo-ketones to form 3-hydroxy-2-oxindoles via palladium catalyzed hydrogenation: a hydrogen-mediated Grignard addition
作者:Inji Shin、Stephen D. Ramgren、Michael J. Krische
DOI:10.1016/j.tet.2015.05.085
日期:2015.9
The reductive cyclization of N-oxoacyl ortho-bromoanilides to form 3-hydroxy-2-oxindoles under the conditions of palladium catalyzed hydrogenation is described. This work may be viewed as a prelude to intermolecular hydrogen-mediated Grignard-type reductive couplings of organic halides with carbonyl compounds.
A Pd-catalyzed spirocyclization involving a sequential carbopalladation, intramolecular C−Hactivation, and a highly regioselective alkyne insertion to afford spirooxindoles and spirodihydrobenzofurans has been achieved. The spirocyclic products were generated in good to excellent yields with complete regiocontrol in a readily scalable procedure.
The amination of 3-nitropyridines with aromatic amides generated from various aminopyridine derivatives proceeded unexpectedly in the position PARA to the nitro group, giving the oxidativenucleophilicsubstitution of hydrogen (ONSH) derived compounds. After optimization, this reaction allowed easy access to interesting 3-nitro-substituted N, N′-dipyridinylamines.
3-硝基吡啶与由各种氨基吡啶衍生物产生的芳族酰胺的胺化在 PARA 到硝基的位置出乎意料地进行,产生了氢 (ONSH) 衍生化合物的氧化亲核取代。优化后,该反应可以轻松获得有趣的 3-硝基取代的 N,N'-联吡啶胺。
Synthesis of Mono- and Bisdihydrodipyridopyrazines and Assessment of Their DNA Binding and Cytotoxic Properties
Aminoalkyl-substituted monomeric and dimeric dihydrodipyridopyrazines have been synthesized and evaluated as antitumor agents. Potent cytotoxic compounds were identified in both series. Biochemical and biophysical studies indicated that all these compounds strongly stabilized the duplex structure of DNA and some of them elicited a selectivity for GC-rich sequences. Sequence recognition by of the dimeric dihydrodipyridopyrazines