Synthetic Transformations of Conjugated Heterodienes: Heterodiene cycloadditions

The present work entails the synthesis of different cross-conjugated (CC) heterodiene systems, and their transformations in various heterocyclic compounds using the hetero Diels-Alder (HDA) methodology. One of the main highlights of present work includes the development of simple and convenient procedure for the synthesis of stable CC azatrienes, and their tandem [2+2] cycloadditions and highly facile [3,3] sigmatropic Cope rearrangements with conjugated ketenes, leading to facile synthesis of various functionalized azocinone derivatives. A generalized and relevant study regarding the reactivity of thiazolic diazadienes with different ketenes was also conducted, and a remarkable increase in reactivity was observed with the introduction of electron donating group across the carbonyl group. Considering the biological and medicinal importance of C-5 or C-6 substituted pyrimidinones, the dienyl moiety of thiazolopyrimidinones was utilized further in Diels-Alder cycloadditions with both symmetrical and unsymmetrical dienophiles. Additionally, the synthesis of various pyrans, thiopyrans, thiophenes, thiazoles, 1,3-thiazines etc. is also described.

Dr Parvesh Singh is currently a Research Scientist in the Department of Chemistry at Durban University of Technology (DUT), South Africa. His research area includes both the synthetic and computational studies of organic molecules. Dr Singh has published 20 papers in International Journals including 2 Book Chapters in the international books.