50 research outputs found
Chemodivergent Manganese-Catalyzed CâH Activation: Modular Synthesis of Fluorogenic Probes
Bioorthogonal diversification of peptides is generally dependent on impractical prefunctionalization methods. Here, the authors develop a manganese(I)-catalyzed CâH fluorescent labeling with BODIPY probes, which enables the development of activatable fluorophores to image cell function
Palladium-Catalyzed Dehydrogenative ÎČâArylation of Simple Saturated Carbonyls by Aryl Halides
A versatile
palladium-catalyzed synthesis of highly substituted α,ÎČ-unsaturated
carbonyl compounds has been developed. In contrast to the known Heck-type
coupling reaction of unsaturated carbonyl compounds with aryl halides,
the present methodology allows the use of stable and readily available
saturated carbonyl compounds as the alkene source. In addition, the
reaction proceeds well with low catalyst loadings and does not require
any expensive metal oxidants or ligands. A variety of saturated aldehydes,
ketones, and esters are compatible for the reaction with aryl halides
under the developed reaction conditions to afford α,ÎČ-unsaturated
carbonyl compounds in good to excellent yields. A possible reaction
mechanism involves a palladium-catalyzed dehydrogenation followed
by Heck-type cross couplings
3d Transition Metals for C-H Activation
C-H activation has surfaced as an increasingly powerful tool for molecular sciences, with notable applications to material sciences, crop protection, drug discovery, and pharmaceutical industries, among others. Despite major advances, the vast majority of these C-H functionalizations required precious 4d or 5d transition metal catalysts. Given the cost-effective and sustainable nature of earth-abundant first row transition metals, the development of less toxic, inexpensive 3d metal catalysts for C-H activation has gained considerable recent momentum as a significantly more environmentally-benign and economically-attractive alternative. Herein, we provide a comprehensive overview on first row transition metal catalysts for C-H activation until summer 2018