A novel multicomponent sulfonylation of alkenes is described for the assembly of various β-substituted arylsulfones using cheap and easily available KSO as a sulfur dioxide source. Of note, the procedure does not need any extra oxidants and metal catalysts and exhibits a relatively wide substrate scope and good functional group compatibility. Mechanistically, an initial arylsulfonyl radical is formed involving the insertion of sulfur dioxide with aryl diazonium salt, followed by alkoxyarylsulfonylation or hydroxysulfonylation of alkenes.
View Article and Find Full Text PDFA novel copper-catalyzed cross-coupling of arylsulfonyl radicals with diazo compounds is described for the synthesis of various arylsulfones under mild conditions. In this reaction, the cheap, environmentally friendly, and readily available inorganic KSO is employed as the sulfur dioxide source for providing arylsulfonyl radicals. In addition, a radical mechanism involving the insertion of sulfur dioxide with aryl radicals followed by the coupling of arylsulfonyl radicals with copper carbenes is proposed.
View Article and Find Full Text PDFA novel and mild metal-free catalyzed radical-mediated cascade spirocyclization of -benzylacrylamides with polyhaloalkanes is proposed for the preparation of polyhalo-substituted azaspirocyclohexadienones. Notably, polyhaloalkanes are employed as efficient alkyl radical sources via the cleavage of C(sp)-H bonds. This protocol undergoes a cascade radical addition and intramolecular cyclization/dearomatization process, and enables the easy construction of multiple chemical bonds and a spiro ring in a single reaction.
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