175658-16-9Relevant academic research and scientific papers
Electroorganic synthesis using a fluoride ion mediator under ultrasonic irradiation: Synthesis of oxindole and 3-oxotetrahydroisoquinoline derivatives
Shen, Yi,Atobe, Mahito,Fuchigami, Toshio
, p. 2441 - 2444 (2004)
(Equation Presented) Anodic intramolecular cyclization of α-(phenylthio)acetamides using a fluoride ion mediator was realized. Under ultrasonic irradiation, cyclization was accelerated markedly to give desired cyclized products in moderate to good yields.
Development of Chiral Ureates as Chiral Strong Br?nsted Base Catalysts
Ishikawa, Sho,Kondoh, Azusa,Terada, Masahiro
supporting information, p. 3724 - 3728 (2020/03/11)
Recently, chiral Br?nsted bases having high basicity have emerged as a powerful tool in developing new catalytic enantioselective reactions. However, such chiral strong Br?nsted base catalysts are still very scarce. Herein, we report the development of a chiral anionic Br?nsted base having a N,N′-dialkyl ureate moiety as a basic site. Its prominent catalytic activity was demonstrated in the enantioselective addition reactions of α-thioacetamides as less acidic pronucleophiles with various electrophiles. Thus, the newly developed chiral catalyst with high accessibility and structural tunability would expand the scope of viable enantioselective transformations under Br?nsted base catalysis.
Development of Chiral Organosuperbase Catalysts Consisting of Two Different Organobase Functionalities
Kondoh, Azusa,Oishi, Masafumi,Terada, Masahiro,Tezuka, Hikaru
supporting information, p. 7472 - 7477 (2020/03/19)
In the field of chiral Br?nsted base catalysis, a new generation of chiral catalysts has been highly anticipated to overcome the intrinsic limitation of pronucleophiles that are applicable to the enantioselective reactions. Herein, we reveal conceptually new chiral Br?nsted base catalysts consisting of two different organobase functionalities, one of which functions as an organosuperbase and the other as the substrate recognition site. Their prominent activity, which stems from the distinctive cooperative function by the two organobases in a single catalyst molecule, was demonstrated in the unprecedented enantioselective direct Mannich-type reaction of α-phenylthioacetate as a less acidic pronucleophile. The present achievement would provide a new guiding principle for the design and development of chiral Br?nsted base catalysts and significantly broaden the utility of Br?nsted base catalysis in asymmetric organic synthesis.
Direct access to α-sulfenylated amides/esters: Via sequential oxidative sulfenylation and C-C bond cleavage of 3-oxobutyric amides/esters
Jiang, Yi,Deng, Jie-Dan,Wang, Hui-Hong,Zou, Jiao-Xia,Wang, Yong-Qiang,Chen, Jin-Hong,Zhu, Long-Qing,Zhang, Hong-Hua,Peng, Xue,Wang, Zhen
supporting information, p. 802 - 805 (2018/02/06)
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 to a series of prospective compounds, and selenium atom can be introduced to the α-sites of the amides in high yields.
Fluorination of sulfanyl amides using difluoroiodoarene reagents
Motherwell, William B.,Greaney, Michael F.,Edmunds, Jeremy J.,Steed, Jonathan W.
, p. 2816 - 2826 (2007/10/03)
A range of sulfur-containing amides have been fluorinated with the hypervalent iodine difluoride reagents 1, and two principal reaction pathways identified. Cephalosporin esters 2 having a heteroatom in the α-position to sulfur undergo fluorination in DCM with cleavage of the carbon-sulfur bond to form novel fluorinated β-lactams 4. Sulfides with electron-withdrawing groups in the α-position undergo α-fluorination in a process analogous to the classical Pummerer reaction. This Fluoro-Pummerer reaction has been exemplified for a range of simple α-phenylsulfanylacetamides 14-19. When β-hydrogens are present in the substrate a different route is followed, with deprotonation by basic fluoride taking place to yield vinyl sulfides 41-43. When an excess of the fluorinating reagent is used these vinyl sulfides can undergo further reaction in a novel tandem Pummerer-Additive-Pummerer process to yield α,β-difluoro sulfides 45-47.
