An efficient, environmentally benign and unprecedented synthesis of various α-sulfenylated amides/esters has been developed under oxygen atmosphere. The reaction shows good functional group tolerance and excellent chemo/regioselectivity. All the desired products were obtained in moderate to excellent yields, even on the gram scale. Practically, the related α-thiol Weinreb amide can be readily transferred
In the field of chiralBrønstedbase catalysis, a new generation of chiralcatalysts has been highly anticipated to overcome the intrinsic limitation of pronucleophiles that are applicable to the enantioselective reactions. Herein, we reveal conceptually new chiralBrønstedbasecatalysts consisting of two different organobase functionalities, one of which functions as an organosuperbase and the other
Development of Chiral Ureates as Chiral Strong Brønsted Base Catalysts
作者:Azusa Kondoh、Sho Ishikawa、Masahiro Terada
DOI:10.1021/jacs.9b13922
日期:2020.2.26
Recently, chiralBrønsted bases having high basicity have emerged as a powerful tool in developing new catalytic enantioselective reactions. However, such chiral strong Brønsted base catalysts are still very scarce. Herein, we report the development of a chiral anionic Brønsted base having a N,N'-dialkyl ureate moiety as a basic site. Its prominent catalytic activity was demonstrated in the enantioselective
Carbanions of five-membered S-heterocycles react with nitroarenes via the ring-opening VNS reaction or oxidativenucleophilicsubstitution of hydrogen. The reaction course is affected by rigidity of the ring.
Electroorganic Synthesis Using a Fluoride Ion Mediator under Ultrasonic Irradiation:<sup>1</sup> Synthesis of Oxindole and 3-Oxotetrahydroisoquinoline Derivatives
作者:Yi Shen、Mahito Atobe、Toshio Fuchigami
DOI:10.1021/ol049152f
日期:2004.7.1
[reaction: see text] Anodic intramolecular cyclization of alpha-(phenylthio)acetamides using a fluorideion mediator was realized. Under ultrasonic irradiation, cyclization was accelerated markedly to give desired cyclized products in moderate to good yields. The local heating effect of ultrasonic irradiation seems to be more advantageous than usual heating.