Switchable selectivity in multicomponent heterocyclizations of acetoacetamides, aldehydes, and 3-amino-1,2,4-triazoles/5-aminopyrazoles

SnIV Porphyrin Scaffolds for Axially Bonded Multiporphyrin Arrays: Synthesis and Structure Elucidation by NMR Studies

“…The transformation of compounds 8 into 9 occurs in a similar way. The same mechanism for analogous compounds was described in our previous publications 3e,4c,4e…”

Unusual direction of three-component reaction involving 2-amino-4-arylimidazoles and carbonyl compounds leading to Knoevenagel-Michael adducts

“…81, 33.77, 55.64, 55.94, 113.36, 114.91, 121.43, 123.87, 127.24, 128.15, 128.82, 129.37, 135.41, 142.15, 147.17, 158.75 6.53;N,9.39. Found: C,69.50;H,6.87;N,9.35. Amino-5-(4-methoxyphenyl)-1H-imidazol-4-yl)(4-chlorophenyl) 65, 33.72, 55.64, 112.67, 114.77, 120.76, 122.51, 128.14, 128.28, 128.75, 129.04, 130.21, 144.19, 147.10, 158.82 (12), 312 (14), 311 (21), 264 (33), 263 (13), 262 (17), 189 (100), 188 (17%).…”

The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

“…The interactions of 3-oxobutanamides with aldehydes and a number of aminoazoles, namely 3-amino-1,2,4-triazoles [7–11], 5-aminotetrazole [9], 5-aminopyrazoles [11], and 5-amino-1,2,3-triazole [12] have previously been investigated. In some cases when the reaction could proceed in two alternative pathways the conditions enabling to control the interaction direction were determined, which made it possible to obtain the desired azoloazine with high chemo- and regioselectivity [11,13–15].…”

“…In some cases when the reaction could proceed in two alternative pathways the conditions enabling to control the interaction direction were determined, which made it possible to obtain the desired azoloazine with high chemo- and regioselectivity [11,13–15]. In particular, three-component heterocyclizations involving 3-amino-1,2,4-triazoles or 4-substituted 5-aminopyrazoles yielded either 4,5,6,7-tetrahydroazolo[1,5- a ]pyrimidine-6-carboxamides under ultrasonication at room temperature (kinetic control) or 4,7-dihydroazolo[1,5- a ]pyrimidine-6-carboxamides at reflux in an applicable solvent (thermodynamic control), respectively (Scheme 1).…”

“…The behavior of the reaction of 5-aminopyrazoles containing substituents in the position 3 is influenced by the structure of aminoazoles and aldehydes, giving rise either to pyrazolopyridine or pyrazolopyrimidine heterocycles. In the authors' opinion, the different outcomes in three-component reactions involving 3-methyl- or 3-aryl-substituted 5-aminopyrazoles can mainly be put down to the steric substituent effect [11]. …”