Dienaminodioate based multicomponent reactions with post-benzylic oxidative transformations mediated by DDQ

Abstract

Multicomponent reactions (MCRs) using dienaminodioate with post-benzylic oxidative transformation mediated by DDQ that afforded a diverse array of products are described.

Recent Advances in the Dearomative Skeletal Editing of Mono-azaarenes

“…Scheme 4 I2-mediated skeletal editing of pyridiniums to 2-formylpyrroles Lankalapalli's group disclosed the skeletal editing of 1,2dihydropyridines (DHPs) with the oxidation of 1,2-DHPs into pyridiniums as the key step (Scheme 5). 11 With treatment with DDQ, 5-1 was smoothly oxidized into pyridinium 5-2, which was easily intercepted by water to produce N,O-ketal intermediate 5-A. Driven by the instability of the thus generated N,O-ketal, the ring was cleaved, thus leading to intermediate 5-B bearing an amino group and an ester group.…”

“…The Lankalapalli group disclosed the skeletal editing of 1,2-dihydropyridines (DHPs) 5-1 to give 2-pyridones 5-3 (Scheme 5). 11 In the key step, 1,2-dihydropyridines 5-1 were smoothly oxidized with DDQ to give pyridiniums 5-2 that were treated with potassium carbonate to give 5-3.…”

“…The Lankalapalli group disclosed the skeletal editing of 1,2-dihydropyridines (DHPs) 5-1 to give 2-pyridones 5-3 (Scheme 5 ). 11 In the key step, 1,2-dihydropyridines 5-1 were smoothly oxidized with DDQ to give pyridiniums 5-2 that were treated with potassium carbonate to give 5-3 . Mechanistically, pyridinium 5-2 is easily intercepted by water to produce N , O -ketal intermediate 5-A ; this is unstable and the ring is cleaved leading to intermediate 5-B bearing an amino group and an ester group.…”

Synthetic applications of hydride abstraction reactions by organic oxidants

“…56 Ravindran and co-workers showed the utility of generating aromatic intermediates from nitrogen-containing heterocycles. 57 Exposing 70 to DDQ provided pyridinium ion 71 within 5 min. Base-mediated hydrolytic rearrangement resulted in the formation of 72 .…”

A combined multicomponent‐acid catalyzed cyclization reaction as an efficient route to novel tricyclic pyrrolo[2,1‐a]isoquinoline derivatives

“…[ 1–3 ] Therefore, development of new and selective multicomponent reaction combined with a subsequent effective annulation strategy is a significant contribution to organic synthesis. [ 4 ] A simple and straightforward method among these strategies is binding of substrates containing dual active sites to access multifused heterocyclic motifs. [ 5–8 ] Therefore, the rationally designed substrates containing suitable functional groups can participate in a combined process to afford the title products.…”