A facile and general synthesis of 2,4,6‐triaryl pyrimidines has been developed. It involves a one‐pot [2+1+1+1+1] pseudo five‐component annulation of one methyl ketone, two aldehydes and two NH4OAc catalyzed by TfOH. One C−C and four C−N bonds are formed during the oxidative annulation process. The reaction shows good tolerance of many important functional groups in air and produces only water as the coproduct, making this methodology a highly versatile alternative to the existing methods for structuring pyrimidine framework.

An efficient one-pot four-component condensation and cyclization of ketones with DMF and ammonium acetate for the synthesis of 2,4-diarylsubstituted pyridines promoted by Selectfluor has been achieved. Symmetrical pyridines were obtained selectively when non-methyl ketones were used as the starting materials. Two CÀ C and CÀ N bonds are formed during the oxidative cyclization process.[a] J.

An iodine-catalyzed double [4 + 2] oxidative annulation of ketones and diamines is described. A multi-pathway coupled domino strategy has been developed for the synthesis of substituted dimeric pyrazines under metal-free conditions. One CÀ C and four CÀ N bonds are formed during this double [4 + 2] oxidative annulation process from two ketones and two diamines.

We report an efficient iron-catalyzed cross-dehydrogenative coupling [4 + 2] annulation of secondary/tertiary anilines with quinazolinones to generate quinoline−spiroquinzolinones. The reaction proceeds smoothly with a relatively broad variety of functional groups, a cheap transition metal catalyst (FeCl 3 ), and environmentally friendly oxidant (H 2 O 2 /O 2 ) under mild reaction conditions. Creatively, N-methylanilines are employed for the first time for the cycloaddition as both methyl and methylene sources attached to the N atom of tetrahydroquinolines.

A novel procedure for a one-pot cascade reaction of oaminoacetophenones and aryl/aliphatic isocyanates catalyzed/oxidized by the [Pd]/[Ag] system was developed. The reaction involves two C− N bond and one C−C bond formations during the double annulation process and the desired indoloquinazolinones and derivatives were afforded up to 81% yields from readily available substrates with a tolerance of a broad variety.

No abstract

A one-pot cascade coupling/annulation reaction for the synthesis of phenanthridines has been developed from arylboronic acids and o-bromo arylamides with DMSO as a carbon source. The desired phenanthridines were obtained in moderate to good yields by using simple procedure.

A one-pot, four-component annulation of 2,3,4,6-tetraarylpyridines from aromatic aldehydes, methyl ketones, diaryl ethanones, and ammonium acetate is described. The reaction features high functional group compatibility in air under solvent-free conditions without any additive and only water as the nontoxic byproduct, providing a strategy for the facile, economical, and eco-friendly construction of multiaryl-substituted pyridines from simple and readily available reactants.