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A new, efficient, and practical radical cyclization of olefinic amides with ketones through α-C(sp3)–H functionalization in the presence of tert-butyl peroxybenzoate (TBPB) is described for the first time. This protocol assembles a wide range of pivotal and useful benzoxazines in good to excellent yields under mild, catalyst-free, ligand-free, and base-free conditions with wide functional group tolerance. Moreover, the mechanistic study indicates that the α-carbonyl radical is involved in this transformation.

An efficient procedure for the selective preparation of hydroxy-, carbonyl- and acetal-containing 2-pyrrolidinones has been developed through radical cyclization of 1,6-dienes initiated by α-C(sp3)–H functionalization of alcohols. This protocol could be conducted at catalyst-free conditions at relatively low temperature (80 °C) by employing commercially available tert-butyl peroxybenzoate (TBPB) as the oxidant.

A green and efficient procedure for the preparation of valuable 2,3-dihydrofurans and benzoxazines has been achieved through halocyclization of olefinic 1,3-dicarbonyls or olefinic amides. This protocol could be conducted under catalyst-, base-, and oxidant-free conditions in aqueous media open to the air at room temperature with good to excellent yields. Notably, the practicality of this method is further highlighted by gram-scale reactions in good yields.

Without using any additives, a practical and eco-friendly methodology has been realized for the tandem double cyclization of 1,6-dienes with easily accessible azobis(alkylcarbonitriles) on water. This chemistry has mild reaction conditions, employing water as the sole solvent, with high regioselectivity and ease of scale-up. Moreover, this is the first example of 1,n-diene cyclization using azobis(alkylcarbonitriles) as a two-carbon unit for the construction of polycyclic skeletons.

A concise and eco-friendly acylation/cyclization of 1,6-dienes with linear ethers under catalyst- and base-free conditions has been developed. tert-Butyl hydroperoxide (TBHP)-promoted tandem cleavage of C(sp3)–H and C(sp3)–O bonds of linear ethers is the key in this process, which provides a straightforward and efficient method to realize acylation reaction. The significant advantages of this method include catalyst- and base-free, mild reaction conditions, high scalability, operational simplicity, ease of scale-up, dual roles of ethers and controllable synthesis.