Novel C-alkylation Reaction of Condensed Thiophenes with Enaminones, Enaminonitriles, Ethoxymethylene Malononitrile, Aryl Vinyl Ketones and ω-Nitrostyrenes

Recent developments in chemical reactivity of N,N-dimethylenamino ketones as synthons for various heterocycles

“…Conversion of 86 into 87 in basic media is believed to proceed via base addition across the double bond and elimination of 85, thus allowing more of the thermodynamic product to be formed (Scheme 26). 55 An interesting reaction leading to cis-enaminone is the condensation of aminothienopyridazines (88a,b) with aminovinyl ketone 23 to yield products of condensation via dimethylamine elimination for which structures 89 or 90 seemed possible. Structure 90 was established for those products based on the 1 H NMR and IR spectral data that revealed involvement of amino function in the reaction.…”

Studies with condensed amino‐thiophenes: Further investigation of reactivity of amino‐thieno‐coumarines and amino‐thieno‐benzo[h]coumarines toward electron‐poor olefins and acetylenes

“…However, we observed the formation of C-1 alkylation products on the thiophene moiety upon reacting 2b with enaminones, ϖ-nitrostyrene, and ethoxymethylenemalononitrile derivatives [9].…”

Alkyl heteroaromatic as precursors to polycyclic heteroaromatics: Recent developments

“…In fact C-1 alkylation of aminothienocoumarins has been observed in our laboratories 46 on reacting ω-nitrostyrene, and aryl vinyl ketones, with 91a to yield 1:1 adducts 115.…”

“…Moreover, several aminothienopyridazines were hydrolysed in acid media to produce the corresponding thiophenones 96. ref. [13,14,31,32,[43][44][45][46][47][48][49] ref. [16] ref.…”