Research Projects

Diazo compounds play a key role in synthetic organic chemistry, and so their reactivity has been actively studied since the late 19th century. Over the years, the researchers have developed several key diazo surrogates that include N-sulfonyl hydrazones, parent hydrazones etc., which have been widely used as potent precursors for diazoalkanes in carbene transfer reactions. Davies conducted extensive studies on the reactivity of various diazo compounds, revealing that donor-acceptor carbenes are highly reactive and exhibit exceptional selectivity in their reactions. Hence, the study on diazo compounds containing donor and acceptor groups has garnered a lot of attention in the last decades. Though the reactivity of different kinds of diazo compounds was widely harnessed, the efforts on diazo compounds containing versatile π-bonds are remain scarce. Despite the well- versatility of alkynes, it is surprising that the study of diazo compounds containing alkynyl donors remains relatively unexplored. The alkynyl diazo compounds are typically generated through a diazo transfer technique, base-promoted decomposition of N-sulfonyl hydrazones, and oxidation of unprotected hydrazones. To date, alkynyl hydrazones or diazo compounds have been investigated for decomposition in the presence of transition metals enabling various reactions such as cyclopropanations, Si-H bond insertion, B-H bond insertion, C-C bond insertions, the Doyle-Kirmse rearrangement, and a multicomponent reaction. Recently, Gurubrahamam’s group reported an unprotected alkynyl hydrazone and studied their reactivity as alkynyl donor-acceptor type reactivity. The group established the alkynyl carbene transfer reactions by employing rhodium and copper catalysis. Also, its noteworthy to mention that such kind of decompositions were only limited to rhodium, copper, silver, and gold-catalysis till date. Alternatively, Palladium-catalysed decomposition of diazo compounds is a special class in transition-metal catalysed carbene transfer reactions. Unlike traditional Rh, and Cu-catalysed carbene reactions; Pd-carbene intermediates undergo migratory insertions that could lead to a unique reactivity and provide new opportunities for novel organic transformations This proposal aims to explore the utility of alkynyl diazoacetates as carbene surrogates in palladium-catalysed reactions which includes palladium–carbene formation, carbonylation of aryl iodides, and migratory insertions. This approach could potentially deliver substituted furan derivatives. Additionally, we will investigate palladium-catalysed cross-coupling reactions involving vinyl halides/amines and alkynyl diazoacetates. Also, the proposal aims at establishing a novel route for the synthesis of highly conjugated π-systems. The proposal will include a critical analysis of the unique transformations and their underlying mechanisms, as well as potential applications in the synthesis of bioactive natural products and pharmaceuticals.

Diazo compounds, Alkynyl carbene, Palladium catalysis, Multicomponent reaction, Heterocycles, π-Extended dienynes