Chemoselectivity Switching in the Rhodium-Catalyzed Reactions of 4-Substituted-1-sulfonyl-1,2,3-triazoles with Allenols: Noticeable Differences between 4-Acyl- and 4-Aryl-Triazoles

An electron-deficient MOF as an efficient electron-transfer catalyst for selective oxidative carbon-carbon coupling of 2,6-di-tert-butylphenol

Naphthalene diimides (NDIs), a type of electron-deficient dye molecule with high quadrupole moment and excellent redox activity, have been utilized in various fields, such as energy transfer, chemical sensing, anion transport, and photo-/electrochromic materials. In this study, an electron-deficient metal-organic framework with one-dimensional channels, Eu₂(BBNDI)₃(DMF)₂ (MOF 1) (H₂BBNDI = N,N'-bis(3-benzoic acid)naphthalene diimide), was successfully constructed based on the naphthalene diimide derivative. Because of the generation of NDI radicals by electron transfer between components, this material exhibits fast-responsive reversible photochromic properties. Moreover, it shows high efficiency and selective oxidation of 2,6-di-tert-butylphenol to its quinone derivative, aldehyde, and dimeric or trimeric phenol derivative by controlling the reaction conditions.

Deciphering the Chameleonic Chemistry of Allenols: Breaking the Taboo of a Onetime Esoteric Functionality

The allene functionality has participated in one of the most exciting voyages in organic chemistry, from chemical curiosities to a recurring building block in modern organic chemistry. In the last decades, a special kind of allene, namely, allenol, has emerged. Allenols, formed by an allene moiety and a hydroxyl functional group with diverse connectivity, have become common building blocks for the synthesis of a wide range of structures and frequent motif in naturally occurring systems. The synergistic effect of the allene and hydroxyl functional groups enables allenols to be considered as a unique and sole functionality exhibiting a special reactivity. This Review summarizes the most significant contributions to the chemistry of allenols that appeared during the past decade, with emphasis on their synthesis, reactivity, and occurrence in natural products.

Rhodium (II)-Catalyzed Synthesis of Tetracyclic 3,4-Fused Indoles and Dihydroindoles

An efficient synthetic method of tetracyclic 3,4-fused indoles and dihydroindoles via rhodium-catalyzed (3+2) cycloaddition of N-tosyl-4-(2-phenoxyphenyl)-1,2,3-triazole was described. The aromatized xanthene derivatives can be achieved in a one-pot synthesis starting from 1-ethynyl-2-phenoxybenzene. The xanthene-based fused heterocycles were considered as the valuable fluorophore.

Rh-Catalyzed Aziridine Ring Expansions to Dehydropiperazines

Piperazines are prevalent in pharmaceuticals and natural products, but traditional methods do not typically introduce stereochemical complexity into the ring. To expand access to these scaffolds, we report Rh-catalyzed ring expansions of aziridines and N-sulfonyl-1,2,3-triazoles to furnish dehydropiperazines with excellent diastereocontrol. Productive ring expansion proceeds via a pseudo-1,4-sigmatropic rearrangement of an aziridinium ylide species. However, the structural features of the carbene precursor are important, as pyridotriazoles undergo competing cheletropic extrusion to furnish ketimines.