First examples of 2,6-diarylnicotinaldehydes prepared under conventional and microwave conditions

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

“…129 Shankaraiah and et al was reported a clean, convenient, and highly efficient method for the rapid construction of pyridine 2,6-diarylnicotinaldehydes 355 by an unexpected self condensation of enaminoketones 1 in the presence of NH 4 OAc in acetic acid under conventional conditions and also under microwave irradiation (Scheme 100). 130 The three-component sequential reaction of enaminones 1d,f-h, cinnamaldehyde 356 and the appropriate amines 357, proceeded smoothly to give 1,3,4-trisubstituted 1,4-dihydropyridines 358a-t in aqueous DMF (Scheme 101). 131,132 Enaminones 1d-g,i was heated at reux with isatin 359 in the presence of an aqueous solution of KOH or NaOH, followed by subsequent acidication with dilute hydrochloric acid to give the quinoline-4-carboxylic acids 360a-e in good to excellent yields (75-90%) (Scheme 102).…”

Synthesis of2H‐benzo[g]furo/thieno/pyrrolo[2,3‐e]indazolesviaIntramolecular Dehydrogenation Photocyclization

“…Compared with 1a , in the absence of hydroxyl group, 4‐(furan‐2‐yl)‐3‐phenyl‐1 H ‐pyrazole 1k was prepared according to literature reports (UV spectroscopy in Figure S3). [ 29‐30 ] By a similar optimization process as 1a , irradiation of 1k (0.25 mmol) in EtOH/H 2 O ( V / V , 95/5) with a high pressure mercury lamp (500 W) at room temperature under Ar atmosphere afforded 3a as the sole product in 61% yield.…”

Electrochemical Oxidative Cross‐Coupling of Enaminones and Thiophenols to Construct C−S Bonds

“…Enaminones are a kind of important structures, which widely exist in numerous pharmaceuticals and agrochemicals [1] . Moreover, enaminones are often used as important versatile intermediates for the preparation of various heterocycles, [2] such as furans, [2a] pyridines, [2b–d] pyrazoles, [2e,f] thiazines, [2g] quinolones [2h,i] . The functionalization of enaminones is a promising strategy to obtain valuable compounds [3] .…”