An efficient, organocatalytic, and ecofriendly method has been developed for the quick construction of a wide array of 3,3-disubstituted oxindoles in good to excellent yields and diastereomeric ratio (up to ≤96:4) with excellent functional group tolerance via an allylic alkylation reaction of cyclic sulfamidate imines with a number of MBH carbonates of isatins in 2-MeTHF as an environmentally benign solvent at room temperature using 5 mol % of DABCO. Furthermore, a metal-free-based one-shot synthesis of a medicinally promising polycyclic spirooxindole with an all-carbon spirocenter has been achieved with outstanding dr value (up to ≤99:1).

A stereo- and chemoselective ring closing reaction of N-sulfonyl ketimines with ethene sulfonyl fluorides promoted by DBU is reported. This selective C–C vs. C–N bond cyclization process delivers to trans-cyclopropanes (dr up to ≤99 : 1) and fused-dihydropyrroles.

As imple, mild, catalytic and efficient method for the straightforwards ynthesiso fa ni nterestingc lass of ar ange of 2-aryl/alkyl-substituted-3-(2-aryl/alkyl-4H-furo[3,2-c]chromen-4-yl)-1H-indolesi ng ood to high yields is reported fort he first time. This atom-efficient method proceeds via AgSbF 6 -catalyzed one-pot sequential intramolecular hydroamination (CÀNb ond formation) of 2-alkynylanilines followed by Friedel-Crafts alkylation/oxa-cyclization (creation of new CÀCa nd CÀOb onds) reaction between in situ generated 2-substituted indoles and several cyclic enynones.

The chemistry related to the exploration of cyclic N-sulfonyl ketimines and their derivatives has attracted significant attention in the last few decades because of their intriguing structures and properties. They...

Microwave-assisted and organobase-promoted eco-friendly one-pot protocol has been developed to construct an interesting class of pyridyl-substituted phenols/α-naphthols containing a carboxylate or aroyl group at C2 position on the pyridine ring. A series of N-sulfonyl ketimines and different kinds of bielectrophiles, such as MBH acetates of nitroalkenes/α-arylacetylenyl-β-arylnitroolefins, were involved in this cyclization process, which delivers good to high yields of aforementioned heterocycles and excels with several compatible functionalities.[a] S.