Sp~3 C-H Bonds Activation Through Radical Process

Compared to sp and sp2 C-H activation,much less research has been devoted to the activation of more inert sp3 C-H bonds. The sp3 C-H bond has a lower acidity and higher bond dissociation energy leads to its difficulty to activate.Therefore, catalytic sp3 C-H bonds activation represent a significantly challenge. In this paper, sp3 C-H bond activation and functionation were achieved through radical processes. This paper contains three parts:(1) The Bu4NI-catalyzed α-acyloxylation of ketones with benzylic alcohols.The Bu4NI-catalyzed reaction of ketones with benzylic alcohols was achieved, leading to α-acyloxycarbonyl compounds in moderate to good yields. This metal-free procedure featured the employment of facilely and commercially available starting materials and TBHP as a clean oxidant with high atom economy.(2) tert-Butyl Peroxybenzoate-Promoted α-Methylation of β-DicarbonylCompoundsA tert-butyl peroxybenzoate(TBPB)-promoted direct α-methylation of β-dicarbonyl compounds has been developed, providing α-methyl derivatives in moderate to good yields. In this procedure, TBPB plays a dual role, serving as both the methyl source and radical initiator. This work represents a key complement to the traditional α-methylation of β-dicarbonyl compounds using methyl iodide.(3) Iodine-catalyzed ammoxidation of methyl arenesA mild method for the direct conversion of methyl arenes into nitriles was developed. The procedure did not require expensive catalysts or toxic additives. In combination with the ubiquity of methyl groups, it represents a facile and green methodology leading to nitriles. A series of aryl methanes especially heteroaryl methanes(30 examples) were applicable in moderate to good yields with good functionality tolerance.