Palladium-catalyzed carbonyl insertion route to pyrido[2-1-b]quinazoline derivatives

Synthesis of Heterocycles via Palladium-Catalyzed Carbonylations

“…In 1987, Tilley and co-workers reported an interesting protocol for their synthesis. 231 Starting from 5-substituted 2-(2-bromoanilino)-pyridine, pyrido[2,1-b]quinazolines were produced under carbonylative conditions. The reaction mechanism was believed to proceed through an acyl palladium species, which undergoes nucleophilic attack by the pyridine nitrogen, leading to ring-closure with loss of palladium(0) and a proton.…”

Pot‐Economical Synthesis of Hydroxylated Arylethenyl‐arylethynyl‐arenes through Sequential Decarboxylative Perkin–Sonogashira Reactions

“…Next, to the same pot, phenylacetylene (2 equiv) and Pd(OAc) 2 (5 mol %) were added, which yielded the desired product 1 b in 13 % yield (Table , entry 1). Furthermore, an arsenal of Pd catalysts and inexpensive ligands were screened, as shown in Table (entries 1–9); PdCl 2 (PPh 3 ) 2 (5 mol %) and PPh 3 (10 mol %) in the presence of piperidine and MIM (1.5 equiv each) provided 1 b in 30 % yield (Table , entry 9). It is known that multimetallic catalytic systems can potentially achieve chemical transformations that are usually difficult with monometallic catalysts because of their synergy .…”

Synthesis of quinazolines and quinazolinones via palladium-mediated approach

“…Finally, the intramolecular nucleophilic aromatic substitution of intermediate 87 or 88 affords the respective terminal linear 82 or the angular 83 product. The active Pd(0) catalyst is regenerated with the assistance of the base.In 1987, Tilley et al[56] reported an interesting protocol for the synthesis of pyrido[2,1-b ]quinazolinones 91 starting from N -(2-bromoaryl)pyridin-2-amines 89 under carbonylative conditions ( Scheme 36 ). Another efficient catalytic protocol for the synthesis of 91 uses similar substrates 90[57] .…”