Given the unique charm of dipole chemistry, intercepting N−O=C dipoles precisely generated by designed processes to develop novel reactivity has become a seminal challenge. The polar fragmentation of 1,3,2‐dioxazolidine species generated through the radical addition of excited nitro(hetero)arenes to alkenes represents a significantly underappreciated mechanism for generating N−O=C dipoles. Herein, we present a photoinduced Bartoli indole synthesis by the oxidative cleavage of alkenes with nitro(hetero)arenes. Various indoles and azaindoles are constructed through the multi‐step spontaneous rearrangement of carbonyl imine intermediates generated by the polar fragmentation of 1,3,2‐dioxazolidine species. Mechanism studies and DFT calculations support that the reaction involves radical cycloaddition, ozonolysis‐type cycloreversion, intramolecular H‐shift of carbonyl imines, and 3,3‐sigmatropic shift of O‐Alkenyl hydroxylamines, etc. The implementation of continuous‐ flow photochemistry, in particular, significantly enhances efficiency, thereby overcoming obstacles to the commercialization process.

High security and effectiveness are critical performance metrics in the data transmission process for satellite remote sensing images, medical images, and so on. Previously, the receiver could gain a high-quality cover image (lossy) after decryption in a separable manner to balance embedding capacity (EC) and security. Completely separable, reversible data hiding in encrypted image (SRDH-EI) algorithms are proposed to address this issue. In this study, the cover image was preprocessed at the sender’s end. The pre-embedded pixels and most significant bits (MSB) were compressed via two coding methods to reserve space. Additionally, the header data were embedded for marking. Finally, auxiliary data and secret data were embedded in a forward “Z” and reverse “Z” shape before and after encryption, respectively. The receiver could extract secret data and decrypt the cover image separately using the keys and markers. The experimental results demonstrate that the algorithm reached a high EC for remote sensing images by utilizing pixel correlation at multiple positions within the groups. The cover image could maintain its entropy during the data embedding process, ensuring security. The decrypted image could be recovered without distortion, furthermore, the receiver could achieve complete separability, so it has good application prospects for remote sensing images.

With the increasing requirements for the security of medical data, military data, and other data transmission, data hiding technology has gradually developed from only protecting the security of secret data to all transmission data. As a necessary technical means, reversible data hiding in encrypted images (RDH-EIs) provides superior performance in terms of security. To simultaneously improve the effectiveness of RDH-EIs, this work proposes a mixed multi-bit layer embedding strategy in encrypted images. The cover image is processed into two categories: available hidden blocks (AHBs) and unavailable hidden blocks (UHBs) at the sender. Then, all data are embedded in the multi-bit layer of the encrypted pixels in AHBs through two embedding strategies to obtain the transmission image. At the receiver, the user can extract the needed data separably according to different keys to achieve error-free extraction of the secret data and lossless recovery of the cover image. The experimental results show that the proposed scheme has the advantages of superior embedding capacity and high decryption quality over the current state-of-the-art works.