Kundan Shaw

Indian Institute of Science Education and Research Bhopal | IISER · Department of Chemistry

Natural product synthesis has been the prime focus for the development of new chemical transformations and the drug discovery. The dimeric and oligomeric hexahydropyrrolo[2,3‐b]indole alkaloids represent a architecturally intriguing class of cyclotryptamine alkaloids. These alkaloids share contiguous stereogenic centers with vicinal all‐carbon quat...

We report an expeditious asymmetric approach to the ergot alkaloids via a catalytic enantioselective -aminoxylation using D-proline as catalyst and a unprecedented highly regioselective Heck cyclization. Utilizing aforementioned strategy, formal total syntheses of ergot alkaloids, (+)-lysergine (1a) and (+)-isolysergine (1b) has been achieved. Imp...

Electrochemical strategies have been a powerful approach for the synthesis of valuable intermediates, in particular heterocyclic motifs. Because of the mild nature, a wide range of nonclassical bond disconnections have been achieved via in situ-generated radical intermediates in a highly efficient manner. In particular, anodic electrochemical oxida...

An efficient electrochemical strategy has been developed for the total synthesis of dimeric hexahydropyrrolo[2,3-b]indole alkaloids. In particular, oxidative dimerization of 3-alkyl 2-oxindoles was developed for this study. A detailed CV...

Dimerization of 3-substituted 2-oxindoles has been developed under a mild electrochemical condition, avoiding toxic chemical oxidants and metal by-products. This methodology forms a C(sp3)-C(sp3) bond at the pseudobenzylic position of two partners of 2-oxindoles with a broad substrate scope. These dimeric structural motifs are important building bl...

A general catalytic asymmetric route to either enantiomers of sesquiterpenes, cuparenes (1-2) and herbertenes (8-9) is disclosed from commercially available 3-methyl cyclopenten-2-one. Following a catalytic enantioselective addition of arylboronic acids to enone 15, compounds 14a-b with all carbon quaternary stereocenters are synthesized in up to 9...

First catalytic asymmetric total synthesis of aromatic sesquiterpene, (−)-ar-teunifolene (1) is featured (3 steps, 75% overall yields) from commercially available 3-methyl cyclohex-2-enone 16. The enantioenriched 3,3-disubstituted cyclohexanone 11 is obtained from Pd(II)-catalyzed enantioselective (p-tolyl)boronic acid addition to 3-methyl cyclohex...

Concise catalytic asymmetric total syntheses of both the enantiomers of aromatic sesquiterpenes, (+)-ar-macrocarpene (1) and (–)-ar-macrocarpene (ent-1) is featured in 4 steps, 66.0% overall yields from commercially available 5,5-dimethylcyclohexane 1,3-dione 13. The enantioenriched 5,5-dimethyl-3-(p-tolyl)cyclohexanone 10 is found to be the key in...