Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China.
Published: June 2024
AI Article Synopsis
Article Abstract
A series of 4-thio/seleno-cyanated pyrazoles was conveniently synthesized from 4-unsubstituted pyrazoles using NHSCN/KSeCN as thio/selenocyanogen sources and PhICl as the hypervalent iodine oxidant. This metal-free approach was postulated to involve the in situ generation of reactive thio/selenocyanogen chloride (Cl-SCN/SeCN) from the reaction of PhICl and NHSCN/KSeCN, followed by an electrophilic thio/selenocyanation of the pyrazole skeleton.
Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China.
A series of 4-thio/seleno-cyanated pyrazoles was conveniently synthesized from 4-unsubstituted pyrazoles using NHSCN/KSeCN as thio/selenocyanogen sources and PhICl as the hypervalent iodine oxidant. This metal-free approach was postulated to involve the in situ generation of reactive thio/selenocyanogen chloride (Cl-SCN/SeCN) from the reaction of PhICl and NHSCN/KSeCN, followed by an electrophilic thio/selenocyanation of the pyrazole skeleton.
The construction of 2-amino-1,3-selenazole skeleton was realized via the PhICl/KSeCN-enabled electrophilic selenocyanation of β-enaminones and β-enamino esters followed by intramolecular cyclization under basic conditions. Compared to the classical Hantzsch strategy that utilizes selenourea or its analogues as starting materials or crucial intermediates, this method might represent an alternative approach for the assembly of 1,3-selenazole framework through a different pathway.
Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China.
The application of PhICl/NHSCN and PhICl/KSeCN reagent systems to the synthesis of the biologically active S/SeCN-containing isocoumarins a process involving thio/selenocyanation, enabled by thio/selenocyanogen chloride generated , followed with an intramolecular lactonization was realized. Gram-scale synthesis, further derivatization to access C4 thio/selenocyanated Xyridin A and anti-tumor activities of the obtained products highlight the potential use of this method.
