Research Contributions
In a span of over 38 years of research career Dr.Yadav has been able to successfully carry out extensive basic and applied research investigations in the synthesis of complex natural products of biological relevance. His expertise and imaginative molecular visionary skills make him a unique chemist with tremendous success in synthesizing a large number of bio-active natural products. Dr.Yadav is a specialist in asymmetric synthesis, to create new chiral centers in complex organic molecules and utilizes it effectively in the synthesis of polypropionate containing natural products such as Rifamycin, Discodermolide, Bryostatin etc., with stereochemical selectivity. This involves introduction of five asymmetric centers in one single step from prochiral 2, 4-dimethyl-3-hydroxy-9-oxanonane through desymmetrization by chiral hydroboration.
The Prins cyclisation reaction mastered by his group allowed him to synthesize several tetrahydropyaran containing natural products with right stereochemistry. Representative examples are . Dr Yadav has discovered, for the first time, the reductive opening of chiral epoxy chlorides to produce chiral propargylic alcohols and allylic alcohols which has helped to synthesize several arachidonic acid metabolites. These include Coriolic acid, dehydrocoriolic acid and (11R-12S-13S)-trihydroxy-9Z, 15Z-octadecadienoic acid which are self-defensive substances against rice-blast disease. He has also done extensive work in the synthesis of hypersensitive metabolites like Trioxillin, Leukotriene-B4, Trioxillin A3 and antifungal agents like Triyne Carbonate L-660, 631 in a highly innovative manner. Dr.Yadav has achieved outstanding success in the oxidative carbonylations of enones and dienones for spiro ketal formations, which paved the way for the preparation of Calcimycin and Routinomycin.
In a pioneering research programme, he has achieved a great deal of success in the synthesis of bioactives like Taxol, Camptothecin, Cervinomycin, Bryostatin, Mappicine ketone, Balanol and several other natural products with a variety of chemical skeletons.His research group has made significant contributions to the frontline chemistry through their innovative work on microwave assisted reactions under solvent free conditions, ecofriendly protection-deprotection strategies, regioselective opening of epoxides with carbon nucleophiles, ‘O’ and ‘C’ glycosidation, allylation and acetylation of azides.
Dr.Yadav has developed synthetic methodologies based on metals and their salts such as Zinc, Indium, Samarium, Scandium, Ytterbium, Titanium, Lithium etc., along with cost-effective technologies for Diltiazem, Ondasetron, Pyrazinamide, Ketotifen, Mefloquin, Tamoxifen etc., for the first time in India. Dr.Yadav has been instrumental in building diverse scaffolds for medicinal chemistry programmes of the institute using environmentally friendly reactions. Some scaffolds such as pyrano- and furano quinolines, cis- isoquinolic acids, isoxazolidines and substituted benzopyrans utilised (4+2) and (3+2) cycloaddition reactions in ionic liquids at room temperature. He has also developed many synthetically useful reactions such as multi-component coupling reactions, conjugate addition reactions and oxidative coupling reactions in ionic liquids for making a variety of compounds such as tetrahydropyranols, 4-chlorotetrahydropyrans, 1,5-benzodiazepine derivatives, cyanohydrins, ß-amino alcohols, ß-azido alcohols, α-aminonitriles, 1,4-dihydropyridines, cis-aziridine carboxylates, trans-cyclopropane carboxylates, α-aminophosphonates, α-hydroxylamino phosphonates, conjugated diynes, binaphthols with a wide structural diversity.
Dr. Yadav’s impeccable instinct made him to foresee the versatility of eco-friendly and environmentally safe insect pheromones as powerful tools through integrated pest management as the best alternatives to the indiscriminate use of pesticides. His exemplary and commendable work in insect pheromones have brought many laurels in control of obnoxious pests on field crops like rice, groundnut, cotton, banana, sugarcane etc., Considering the need of high scientific inputs for the development of agricultural practices in our country for better and high agro produce, Dr.Yadav has taken an ambitious program at the institute for development of pheromone application technology and agro chemicals. He succeeded in isolating and identifying some sex pheromone systems. His research findings have been published in over 975 research papers with more than 15000 citations, 150 Indian and International patents and he has also delivered over 375 abstracts in National and International Symposiums. Dr. Yadav is most sought after as a research guide for doctoral and post doctoral programmes and over 140 research scholars obtained their degrees under his guidance. He is a recognized PhD supervisor in most of the universities in the country.