32 research outputs found
Yield and mineral nutrition of soybean, maize, and Congo signal grass as affected by limestone and slag
Full text linkIn vitro combination therapy using low dose clotrimazole and photodynamic therapy leads to enhanced killing of the dermatophyte Trichophyton rubrum
Get PDFDissolution Testing of Hardly Soluble Materials by Surface Sensitive Techniques: Clotrimazole from an Insoluble Matrix
Get PDFEffects of surface application of dolomitic limestone and calcium-magnesium silicate on soybean and maize in rotation with green manure in a tropical region
Full text linkGoldâCatalyzed Regioselective TetradehydroâDielsâAlder Reaction of YneâYnamides: Access to 2,3âDihydrobenzo[ f ]indoles
No full textInternational audienc
Umpolung Reactivity of Ynamides: An Unconventional [1,3]-Sulfonyl and [1,5]-Sulfinyl Migration Cascade
No full textInternational audienc
An unconventional sulfur-to-selenium-to-carbon radical transfer: chemo-and regioselective cyclization of yne-ynamides
No full textInternational audienc
Ring Expansion and 1,2âMigration Cascade of Benzisoxazoles with Ynamides: Experimental and Theoretical Studies
No full textInternational audienc
Regioselective Synthesis of 2,4,5-Trisubstituted Oxazoles and Ketene Aminals via Hydroamidation and Iodo-Imidation of Ynamides
No full textA novel
and straightforward protocol is demonstrated for the synthesis
of highly substituted oxazoles from readily accessible ynamides in
the presence of ytterbiumÂ(III) trifluoromethanesulfonate [YbÂ(OTf)<sub>3</sub>], <i>N</i>-iodosuccinimide (NIS), and acetonitrile.
Multiple oxazole skeletons in the aryl periphery are constructed in
a single operation for the first time. The hydroamidation and iodo-imidation
of ynamides to trisubstituted and tetrasubstituted ketene aminals
is exemplified. An isotope labeling experiment is used to identify
the oxygen source in this transformation. The reactions are scalable
to the gram scale, testifying the robustness of the transformations
Dimethyl Sulfoxide and <i>N</i>âIodosuccinimide Promoted 5-<i>exo-dig</i> Oxidative Cyclization of Yne-Tethered Ynamide: Access to Pyrrolidones and Spiro-pyrrolidones
No full textAn
unprecedented metal-free dimethyl sulfoxide (DMSO) and <i>N</i>-iodosuccinimide mediated regioselective 5-<i>exo-dig</i> oxidative cyclization of an in situ generated enol equivalent of
amides from ynamides bearing internal alkynes is demonstrated. The
reaction allows easy access to functionalized pyrrolidone skeletons.
Pyrrolidones having 3-<i>o</i>-biaryl motifs successfully
undergo intramolecular electrophilic cyclization with the α,ÎČ-unsaturated
olefin, furnishing spiro-pyrrolidone motifs. A one-pot sequential
5-<i>exo-dig</i> cyclization of the yne-tethered ynamides,
followed by electrophilic cyclization of the pyrrolidone, is presented.
The role of DMSO in the transformation is clarified, and a tentative
reaction pathway is proposed
