نتایج جستجو برای: oxindole
تعداد نتایج: 442 فیلتر نتایج به سال:
An efficient and powerful organocatalytic cascade reaction was achieved for the synthesis of biologically important chiral spiro[pyrrolidin-3,2'-oxindoles] using very simple and readily available starting materials. Three C-C bonds and four contiguous stereogenic centers including one quaternary stereocenter were established in a single operation with reasonable yields and good stereoselectivity.
(E)-3-Ylideneoxindoles are prepared in methanol in reasonable to good yields, as adducts of photochemical 5-exo-trig of aryl radicals, in contrast to previously reported analogous radical cyclizations initiated by tris(trimethylsilyl)silane and azo-initiators that gave reduced oxindole adducts.
A straightforward synthesis of 4,4-spirocyclic indol γ-lactams by tandem radical cyclization of iodoaryl allyl azides with CO was achieved. The reaction of iodoaryl allyl azides, TTMSS and AIBN under CO pressure (80 atm) in THF at 80 °C gave the desired 4,4-spirocyclic indoline, benzofuran, and oxindole γ-lactams in moderate to good yields.
A highly enantioselective organocatalytic vinylogous aldol-cyclization cascade reaction of 3-alkylidene oxindoles to isatins has been achieved by using bifunctional organocatalysts. The unexpected intramolecular lactonization which follows the initial aldol reaction, leading to the cleavage of the oxindole ring and generation of enantioenriched spirooxindole dihydropyranones in good to excellen...
Two new oxindole alkaloids isatinone A (1) and B (2) have been isolated from Isatis costata, along with the known trisindoline. Their structures have been assigned on the basis of spectroscopic techniques and chemical studies. Both new compounds showed significant antifungal activity.
Palladium-Catalyzed One-Pot Approach to 3-(Diarylmethylene)oxindoles from Propiolamidoaryl Triflate.
3-(Diarylmethylene)oxindoles have been synthesized from propiolamidoaryl triflate utilizing a palladium-catalyzed one-pot reaction consisting of three successive reactions: Sonogashira, Heck, and Suzuki-Miyaura. This method allows for the production of a complex skeleton of 3-(diarylmethylene)oxindole from propiolamidoaryl triflate using a commercially available aryl iodide and arylboronic acid...
The first enantioselective catalytic 1,2-hydroperoxidation has been achieved in the presence of PEG-600 using an acid-base bifunctional chiral squaramide as the organocatalyst, affording a range of enantioenriched α-N-substituted hydroperoxides bearing an oxindole moiety with excellent stereoselectivities (up to 99% ee).
A highly stereoselective total synthesis of the alkaloid natural product welwitindolinone A isonitrile has been completed. The synthesis utilizes a chloronium ion mediated semi-pinacol rearrangement to simultaneously install the C10 quaternary center and neopentyl chlorine and a novel anionic cyclization to construct the spiro-oxindole with complete stereocontrol.
: Oxindoles are an important class of heterocyclic scaffolds widely present in natural products and bioactive compounds. For this reason, a plethora methodologies for the stereoselective synthesis enantioenriched oxindoles has been studied over years. Among all reported synthetic strategies, organocatalysis proven to be powerful tool asymmetric compounds being step- atom-economical, environment...
In the title compound, C(23)H(18)N(2)O(4)·H(2)O, the two oxindole rings subtend a dihedral angle of 54.29 (5)°. The crystal structure is stabilized by intermolecular N-H⋯O, O-H⋯O and C-H⋯π inter-actions.
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