Synthesis and Single Crystal Structures of Substituted-1,3-Selenazol-2-amines

Abstract

The synthesis and X-ray single crystal structures of a series of new 4-substituted-1,3-selenazol-2-amines is reported. The efficient preparation of these compounds was carried out by two-component cyclization of the selenoureas with equimolar amounts of α-haloketones. The selenoureas were obtained from the reaction of Woollins’ reagent with cyanamides, followed by hydrolysis with water. All new compounds have been characterized by IR spectroscopy, multi-NMR (1H, 13C, 77Se) spectroscopy, accurate mass measurement and single crystal X-ray structure analysis.

Zero-, one-, two- and three-dimensional supramolecular architectures sustained by Se…O chalcogen bonding: A crystallographic survey

“…The selenium atom in 82 [74] forms part of a four-membered ring and the molecules assemble into a zig-zag chain via Se … O(sulphoxide) contacts, Fig. 9 f. The chains in 83 [145] are sustained by Se … O(methoxy) interactions, and in 84 [146] , 85 [101] , 86 [147] and 87 [148] by Se … O(carbonyl) interactions. Compound 85 , Fig.…”

Preparation and Characterization of Phenyl Phosphine Diselenide – The Monomeric Form of Woollins' Reagent

“…reagent [1,2] (2,4-diphenyl-1,3,2,4-diselenadiphosphetan-2,4-diselenide; 2) has been employed in a variety of selenium atom transfer reactions [3,4] and organic P-Se heterocycle syntheses. [5][6][7] At temperatures above 100°C, 2 has been assumed to dissociate into its monomer phenyl phosphine diselenide (1).…”

Celebrating Two Centuries of Research in Selenium Chemistry: State of the Art and New Prospective

“…Woolins’ group reported here the synthesis and characterization of a series of new 4-substituted-1,3-selenazol-2-amines. The synthesis was carried out by two-component cyclization of the selenoureas and α-haloketones and the selenoureas were obtained from the reaction of Woollins’ reagent with cyanamides, followed by hydrolysis [ 3 ]. Other contributions pay attention to the ecofriendly aspect of synthesis, such as the paper from Braga et al [ 4 ] that described an efficient copper-catalyzed synthesis of unsymmetrical disubstituted chalcogenides using ligand- and solvent-free conditions; our manuscript, in which the use of novel zinc selenates was proposed for the preparation in “on-water” conditions of selenol esters [ 5 ]; and the efforts of Lenardao’s and Perin’s groups who suggested the use of glycerol as ecofriendly raw material in the synthesis of organoselanyl and organotellanyl alkynes [ 6 ] or the green hydroselenation of aryl alkynes to afford divinyl selenides as precursor in the synthesis of resveratrol [ 7 ].…”