An efficient and general method for the synthesis of unsymmetrical tetrasubstituted ureas from carbamoylimidazole is described. The conversion is achieved by the concurrent quarternization of the imidazole nitrogen and activation of amines with AlMe(3).

nickel (ii) and copper (ii) complexes of highly unsymmetrical tetradentate schiff base have been synthesized by the template reaction of half-units n-(1-hydroxy-2-acetonaphtone)-1-amino-2-phenyleneimine (hl) and n-(2-hydroxyacetophenone)-1-amino-2-phenyleneimine (hl1) with the glyoxalphenylhydrazone. the complexes have been characterized by elemental analyses, conductance, ir, 1h nmr and uv spe...

Synthesis of unsymmetrical and bifunctional building blocks based on 1,1,3,3-tetramethyldisiloxane is presented which allows compounds with a wide spectrum reactive groups bonded to alkenes alkynes be obtained.

Unsymmetrical ditopic ligands can self-assemble into reduced-symmetry Pd2L4 metallo-cages with anisotropic cavities, implications for high specificity and affinity guest-binding. Mixtures of cage isomers form, however, resulting in undesirable system heterogeneity. It is paramount to be able design components that preferentially form a single isomer. Previous data suggested computational method...

Catalytic hydrogenation of dibenzyl 5-dipyrroketone-2,9-dicarboxylates followed by decarboxylative iodination affords a 2,9-diiododipyrroketone which gives a 2,5,9-trichlorodipyrromethene hydrochloride after nucleophilic addition/elimination, with adventitious chloride to replace the two iodide groups. Treatment with BF3·Et2O gives a 3,5,8-trichloro-BODIPY that readily undergoes regioselective ...

The direct synthesis of aryl triflones, that is, trifluoromethanesulfonyl arenes, was achieved through the trifluoromethanesulfonylation of benzynes. The trifluoromethanesulfonyl group, one of the fluorinated functional groups, is a highly electron-negative and mild lipophilic substituent. Aryl triflones have high potential in the synthesis of bioactive compounds and specialty materials. The tr...

In this paper, we are proposing an approach to minimize very high density salt and pepper noise through trimmed global mean. The Modified decision based unsymmetrical trimmed median filter tries to remove high density salt and pepper noise by taking the mean value of the elements within the processing window. This algorithm fails if all the elements within the processing window is either ‘0’ or...

Unsymmetrical 1,2-diols are hardly accessible by reductive pinacol coupling processes. A successful execution of such a transformation is bound to a clear recognition and strict differentiation of two similar carbonyl compounds (aldehydes → secondary 1,2-diols or ketones → tertiary 1,2-diols). This fine-tuning is still a challenge and an unsolved problem for an organic chemist. There exist seve...