A cascade Michael/Michael/oxa-Michael reaction between curcumins and isatylidene malononitriles has been developed. Multicyclic spirooxindoles were prepared in excellent yields and diastereoselectivities. DMAP was found to catalyze this transformation efficiently under mild reaction conditions.
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http://dx.doi.org/10.1039/c2ob06995d | DOI Listing |
Org Lett
April 2023
School of Pharmaceutical Sciences and Chongqing Key Laboratory of Natural Drug Research, Chongqing University, Chongqing 401331, P. R. China.
An organocatalyzed stereoselective domino reaction as a facile approach to multicyclic spirooxindole derivatives bearing two stereogenic quaternary carbon atoms is reported. The alkyl-substituted chiral thiourea catalyst was efficient for the reaction to tolerate a wide range of substrates, furnishing a new class of spirooxindole derivatives bearing an ,-acetal-fused tricyclic skeleton or tetrahydroxanthone moiety in moderate to good yields with good to excellent selectivities. The products generated from this method have promising anticancer activities.
View Article and Find Full Text PDFRSC Adv
May 2019
Department of Chemistry, Faculty of Science, Imam Khomeini International University Qazvin Iran +98 28 33780040.
A new versatile strategy involving a sequential four-component reaction of the nitroketene dithioacetals, alkylamine/benzylamine, isatin and various enolizable active methylene structures (pyrazolone, barbituric acid, 1,3-indandione and 2-hydroxy-1,4-naphthoquinone) as precursors under mild and catalyst-free conditions results in the synthesis of new functionalized spirooxindole pyrans named spiro[indoline-3,4'-pyrano[2,3-]pyrazol], spiro[indoline-3,5'-pyrano[2,3-]pyrimidine], spiro[indeno[1,2-]pyran-4,3'-indoline] and spiro[benzo[]chromene-4,3'-indoline] in moderate to good yields. The use of various active methylene compounds affords a range of skeletally distinct spirooxindole-based heterocycles with potential biological properties. The present strategy has many advantages, such as convenient one-pot operation, simple workup procedures and straightforward isolation without using tedious purification steps such as column chromatography, progress under catalyst-free condition and high molecular diversity.
View Article and Find Full Text PDFChem Commun (Camb)
February 2013
Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, State Key Laboratory of Applied Organic Chemistry and Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
The first organocatalytic Michael-cyclization cascade reaction between isothiocyanato oxindoles and unsaturated pyrazolones has been developed. The multicyclic spiro[oxindole/thiobutyrolactam/pyrazolone] core structures containing three contiguous stereogenic centers, including two spiro quaternary centers, were prepared with excellent diastereo- (up to >20 : 1) and enantioselectivities (up to 99% ee).
View Article and Find Full Text PDFOrg Biomol Chem
February 2012
Institute of Drug Synthesis and Pharmaceutical Process, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China.
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