Triarylamines are demonstrated as novel, tunable electroactivated photocatalysts that use dispersion precomplexation to harness the full potential of the visible photon (>4.0 V vs. SCE) in anti-Kasha photo(electro)chemical super-oxidations of arenes.
Enantioselective synthesis of fully substituted allenes has been a challenge due to the non-rigid nature of the axial chirality, which spreads over three carbon atoms. Here we show the commercially available simple Rh complex may catalyse the CMD (concerted metalation/deprotonation)-based reaction of the readily available arenes with sterically congested tertiary propargylic carbonates at ambient temperature affording fully substituted allenes. It is confirmed that the excellent designed regioselectivity for the C–C triple bond insertion is induced by the coordination of the carbonyl group in the directing carbonate group as well as the steric effect of the tertiary O-linked carbon atom. When an optically active carbonate was used, surprisingly high efficiency of chirality transfer was realized, affording fully substituted allenes in excellent enantiomeric excess (ee).
Synthetic photoelectrochemistry (PEC) is receiving increasing attention as a new frontier for the generation and handling of reactive intermediates. PEC permits selective single‐electron transfer (SET) reactions in a much greener way and broadens the redox window of possible transformations. Herein, the most recent contributions are reviewed, demonstrating exciting new opportunities, namely, the combination of PEC with other reactivity paradigms (hydrogen‐atom transfer, radical polar crossover, energy transfer sensitization), scalability up to multigram scale, novel selectivities in SET super‐oxidations/reductions and the importance of precomplexation to temporally enable excited radical ion catalysis.
A Rh(III)-catalyzed o-C-H bond functionalization-based allenylation reaction of allenylsilanes 2 with N-methoxybenzamides 1 affords poly-substituted allenylsilanes with a wide range of attractive functional groups in moderate to excellent yields under very mild conditions (20 °C, compatible with ambient air and moisture). Those products may be transformed to different products with attractive structural features. Careful mechanistic studies suggest the reaction proceeds via o-rhodation, regioselective insertion, and β-H elimination.
Fused tricyclic skeleton in one shot: a RhIII catalyzed formal [4 + 2 + 2] cyclization of N-pivaloyloxybenzamides 1 with 1,6-allene-enes 2 adding two cycles to the benzene ring compatible with ambient air and moisture with a tolerance of many synthetic useful functional groups at room temperature have been developed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.