Search

A new AgOTf‐catalyzed domino reaction of 2‐alkynylbenzaldehyde and 4‐amino‐1‐methyl‐3‐propyl‐1H‐pyrazole‐5‐carboxamide has been reported via a sequential condensation, cyclization, and acetylenic hydroamination process. The developed protocol provides an efficient and modular access to a range of new fused tetracyclic heterocycle 6‐aryl‐9‐methyl‐11‐propyl pyrazolo[4′,3′:4,5]pyrimido[2,1‐a]isoquinolin‐8(9H)‐ones with two new rings in good yields. [ABSTRACT FROM AUTHOR]

A CuI/L‐proline‐catalyzed reaction of 2‐(2‐bromophenyl)‐4,5‐diaryl‐1H‐imidazole and potassium ethylxanthate unexpectedly gave bis(2‐(4,5‐diaryl‐1H‐imidazol‐2‐yl)phenyl)sulfane derivatives in high yields, rather than 2,3‐diphenyl‐5H‐benzo[e]imidazo[1,2‐c]thiazine‐5‐thione. This cascade procedure provided an efficient method to synthesize diphenylsulfanes using potassium ethylxanthate as a new type of sulfur source via the Csp2S bond Ullmann reaction twice. [ABSTRACT FROM AUTHOR]

Aldehyde could undergo not only the subsequent condensation and cyclization with 2‐aminothiophene‐3‐carboxamide to build a pyrimidine ring, but also a Friedel‐Crafts alkylation reaction with thiophene moiety to give unexpected 6‐benzyl‐2‐arylthieno[2,3‐d]pyrimidin‐4(3H)‐ ones in good yields catalyzed by concentrated HCl. [ABSTRACT FROM AUTHOR]

A novel method for the synthesis of dibenzo[b,f]imidazo[1,2‐d][1,4]oxazepine derivatives was described via cascade Csp2N and Csp2O bond constructions. It was a crossed double Ullmann reactions using 4,5‐diaryl‐2‐(2‐hydroxylphenyl)‐1H‐imidazole as the double nucleophilic centers in the presence of Cs2CO3, while 1‐bromo‐2‐iodobenzene was used as a substrate catalyzed by CuI and o‐phenanthroline in good yields. [ABSTRACT FROM AUTHOR]

The α‐arylation between cyanoacetate and 2‐(2‐bromophenyl)‐1H‐perimidine took place first catalyzed by CuI/L‐proline in the presence of NaHCO3, and then the amino on perimidine chemoselectively attacked the cyano group to undergo a nucleophilic addition, giving a series of 13‐aminoisoquinolino[2,1‐a]perimidine‐12‐carboxylate derivatives in good yields. [ABSTRACT FROM AUTHOR]

Two series of furo[3,2- f]quinoline-2-carboxylate were obtained via a three-component reaction of aldehydes, 5-aminobenzofuran-2-carboxylate, and 4-hydroxy-2 H-chromen-2-one or cyclopentane-1,3-dione in DMF under catalyst-free condition in high yields. This one-pot three-component reaction provided an efficient method for the synthesis of fused polycyclic heterocycles for bioactive screening. [ABSTRACT FROM AUTHOR]