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Due to the directional nature of sp3-hybridized orbitals and the absence of π-orbitals, the oxidative cleavage of the kinetically and thermodynamically stable C(sp3)–C(sp3) bond is extremely difficult and remains scarcely explored. In this work, under the double argument of quantum mechanics (QM) computations and meticulous experiments on our well-designed C–C single bond cleavage mechanism, we discovered a means of photoinduced selective oxidative C(sp3)–C(sp3) bond cleavage in arylamines, easily achieved by simple visible light irradiation using O2 as a benign oxidant under very mild conditions. The utility of our methodology was demonstrated by the C(sp3)–C(sp3) bond cleavage in morpholine/piperazine arylamines with excellent functional group tolerance. Importantly, our methodology is noteworthy, not only in that it does not require any catalysts, but also in that it provides valuable possibilities for the scalable functionalization of clinical drugs and natural products. [ABSTRACT FROM AUTHOR]

Due to the particularity of the thiocarbonyl group (C＝S bond), only limited C(sp3)–H thiocarbonylation methods, especially efficient and convenient methods, have been developed for the synthesis of thioamides. Inspired by the "solvent-specificity-based" design strategy, we discovered a simple, practical and environmentally friendly C(sp3)–H thiocarbonylation of benzylamine substrates for facile thioamide synthesis under catalyst-free conditions. A diverse array of benzylamine derivatives were tolerated by this catalyst-free thiocarbonylation. Furthermore, the (QM) computations and well-designed experiments on the reaction mechanism revealed that this thiocarbonylation depends on the specific solvent that initially drives this reaction through the intermolecular hydrogen atom transfer (HAT). And the following single electron transfer (SET) induces the electron-catalyzed C–S bond formation and intramolecular HAT realizing the final establishment of the C＝S bond. [ABSTRACT FROM AUTHOR]

It is almost a consensus that decarbonylation of the aldehyde group (–CHO) needs to not only be mediated by transition metal catalysts, but also requires severe reaction conditions (high temperature and long reaction time). In this work, inspired by the "conformational-selectivity-based" design strategy, we broke this consensus and discovered a catalyst-free photodecarbonylation of the aldehyde group. It revealed that decarbonylation can be easily achieved with visible light irradiation by introducing a tertiary amine into the ortho-position of the aldehyde group. A diverse array of tertiary amines is tolerated by our photodecarbonylation under mild conditions. Furthermore, the (QM) computations of the mechanism and the experiments on well-designed special substrates revealed that our photodecarbonylation depends on the conformational specificity of the aldehyde group and tertiary amine, and occurs through an unusual [1,4]-H shift and a subsequent [1,3]-H shift. [ABSTRACT FROM AUTHOR]