348163-48-4Relevant articles and documents
Structure-based modification of 3-/4-aminoacetophenones giving a profound change of activity on tyrosinase: From potent activators to highly efficient inhibitors
You, Ao,Zhou, Jie,Song, Senchuan,Zhu, Guoxun,Song, Huacan,Yi, Wei
, p. 255 - 262 (2015/03/04)
In this study, we developed 3-/4-aminoacetophenones and their structure-based 3-/4-aminophenylethylidenethiosemicarbazide derivatives, respectively, as novel tyrosinase activators and inhibitors. Notably, all the obtained thiosemicarbazones displayed more potent tyrosinase inhibitory activities than kojic acid. Especially, compound 7k was found to be the most active tyrosinase inhibitor with IC50 value of 0.291 1/4M. The structure-activity relationships (SARs) analysis showed that: (1) the amine group was absolutely necessarily for determining the tyrosinase activation activity; (2) the introduction of thiosemicarbazide group played a very vital role in transforming tyrosinase activators into tyrosinase inhibitors; (3) the phenylethylenethiosemicarbazide moiety was crucial for determining the tyrosinase inhibitory activity; (4) the type of acyl group had no obvious effect on the inhibitory activity; (5) the position of amide substituent on the phenyl ring influenced the tyrosinase inhibitory potency. Moreover, the inhibition mechanism and inhibition kinetics study revealed that compound 7k was reversible and non-competitive inhibitor, and compound 8h was reversible and competitive-uncompetitive mixed-II type inhibitor.
Pd-catalyzed amidations of aryl chlorides using monodentate biaryl phosphine ligands: A kinetic, computational, and synthetic investigation
Ikawa, Takashi,Barder, Timothy E.,Biscoe, Mark R.,Buchwald, Stephen L.
, p. 13001 - 13007 (2008/09/17)
We present results on the amidation of aryl halides and sulfonates utilizing a monodentate biaryl phosphine-Pd catalyst. Our results are in accord with a previous report that suggests that the formation of κ2- amidate complexes is deleterious to the effectiveness of a catalyst for this transformation and that their formation can be prevented by the use of appropriate bidentate ligands. We now provide data that suggest that the use of certain monodentate ligands can also prevent the formation of the κ2-amidate complexes and thereby generate more stable catalysts for the amination of aryl chlorides. Furthermore, computational studies shed light on the importance of the key feature(s) of the biaryl phosphines (a methyl group ortho to the phosphorus center) that enable the coupling to occur. The use of ligands that possess a methyl group ortho to the phosphorus center allows a variety of aryl and heteroaryl chlorides with various amides to be coupled in high yield.
