@article { ISI:000365952200050, title = {Ammonium persulfate activated DMSO as a one-carbon synthon for the synthesis of methylenebisamides and other applications}, journal = {RSC Advances}, volume = {5}, number = {123}, year = {2015}, month = {NOV}, pages = {101641-101646}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Activation of DMSO to work as an economical and environmentally benign one-carbon synthon has been achieved by using a bench-top reagent ammonium persulfate for general and efficient access to symmetrical methylenebisamides from primary amides. This methodology was used to achieve a three-component Mannich reaction using acetophenone, saccharin and DMSO to furnish a beta-amino ketone. It also provided a metal-free synthesis of thiadiazole and bis(phenyl)methane. Effectively, this method uses DMSO as a safer surrogate to formaldehyde. A mechanism for methylenebisamide formation involving radical intermediates has been proposed based on mechanistic studies.

}, issn = {2046-2069}, doi = {10.1039/c5ra21801b}, author = {Mahajan, Pankaj S. and Tanpure, Subhash D. and More, Namita A. and Gajbhiye, Jayant M. and Mhaske, Santosh B.} } @article { ISI:000356324000001, title = {Radical-mediated dehydrative preparation of cyclic imides using (NH4)(2)S2O8-DMSO: application to the synthesis of vernakalant}, journal = {Beilstein Journal of Organic Chemistry}, volume = {11}, year = {2015}, month = {JUN}, pages = {1008-1016}, publisher = {BEILSTEIN-INSTITUT}, address = {TRAKEHNER STRASSE 7-9, FRANKFURT AM MAIN, 60487, GERMANY}, abstract = {

Ammonium persulfate-dimethyl sulfoxide (APS-DMSO) has been developed as an efficient and new dehydrating reagent for a convenient one-pot process for the synthesis of miscellaneous cyclic imides in high yields starting from readily available primary amines and cyclic anhydrides. A plausible radical mechanism involving DMSO has been proposed. The application of this facile one-pot imide forming process has been demonstrated for a practical synthesis of vernakalant.

}, keywords = {APS-DMSO, imides, practical synthesis, radical-mediated, vernakalant}, issn = {1860-5397}, doi = {10.3762/bjoc.11.113}, author = {Garad, Dnyaneshwar N. and Tanpure, Subhash D. and Mhaske, Santosh B.} } @article { ISI:000380182400037, title = {Radical beckmann rearrangement and its application in the formal total synthesis of antimalarial natural product isocryptolepine via C-H activation}, journal = {Organic Letters}, volume = {18}, number = {14}, year = {2016}, month = {JUL}, pages = {3450-3453}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The Beckmann rearrangement of ketoximes, mediated by ammonium persulfate-dimethyl sulfoxide as a reagent, has been achieved under neutral conditions. Based on the radical trapping and O-18-labeling experiments, the transformation follows a mechanism involving a radical pathway. The scope and generality of the developed protocol has been demonstrated by 19 examples. The developed protocol and Pd-catalyzed intramolecular double C-H activation were used as key steps in the formal total synthesis of antimalarial natural product isocryptolepine.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.6b01634}, author = {Mahajan, Pankaj S. and Humne, Vivek T. and Tanpure, Subhash D. and Mhaske, Santosh B.} }