Diastereotopos-differentiating C–H activation reactions at methylene groups

Abstract

The activation of C-H bonds has become a widely used method which allows for the direct transformation of C-H bonds into synthetically more valuable C-C and C-X bonds in a selective manner. This critical review aims to summarize and to highlight a specific subgroup of these transformations, C-H activation reactions of chiral substrates bearing diastereotopic hydrogen atoms at methylene groups (95 references).

Stereocontrolled Synthesis of (−)-Bactobolin A

“…With access to carbamate 12 , we were poised to investigate the intramolecular C–H amination reaction to form the oxazolidinone ring and specifically the C4–N bond . The multitude of C–H bonds potentially reactive in the amination reaction, including the precarious C–H bond of the dichloromethyl group, presented a particularly interesting case for the rhodium­(II)-catalyzed amination methodology developed by the Du Bois laboratory .…”

New organometallic ruthenium(ii) complexes containing chelidonic acid (4-oxo-4H-pyran-2,6-dicarboxylic acid): synthesis, structure and in vitro biological activity

“…1 Intramolecular C-H activation reactions are one of the major discoveries of organometallic chemistry that provide access to metallacyclic derivatives of transition metal complexes 2,3 and cyclometallation is one of the most commonly used methods in the activation of C-H bonds. 4 Though nearly all transition metals have been successfully employed for cyclometallation, the use of palladium, 5,6 ruthenium, 7 rhodium, 8 copper 9 or iron 10,11 complexes has set the stage for chemo-, site-, 12 diastereo-, 13,14 and/or enantioselective 15 C-H bond functionalizations. Although palladium is, without any doubt, the transition metal that has been the most studied to promote the formation of metallacycles, 16 ruthenium(II) derivatives could efficiently complement their widely used palladium(II) congeners.…”

Manganese-Catalyzed Asymmetric Oxidation of Methylene C–H of Spirocyclic Oxindoles and Dihydroquinolinones with Hydrogen Peroxide

“…C–H bonds are ubiquitous structural units in readily available hydrocarbons as well as other organic molecules; thus, methods for direct transforming of C­( sp 3 )–H bonds into oxygen-containing compounds (e.g., alcohol, ketone) have been explored extensively . Enantioselective oxidation of C­( sp 3 )–H bonds that can produce chiral alcohols or ketones directly, however, has proven to be a long-standing challenging goal . Previous studies focused on the use of chiral metalloporphyrins and analogues.…”