Homogeneous electromediated reduction of the 2-cyclohexen-1-one by transition metals

Synthetic Organic Electrochemical Methods Since 2000: On the Verge of a Renaissance

“…635 Indirect cathodic reduction of CC double bonds has also been reported (Figure 40B). 636,637 Navarro and co-workers investigated mediated cathodic reductions of cyclohexanoneit was observed that the use of Ni 2+ mediators and a Ni anode led to the formation of cyclohexanone whereas employing a Fe 2+ mediator in combination with a Fe sacrificial anode afforded cyclohexanol exclusively. Electrochemical reduction of other activated olefins such as Michael acceptors and dienes with nickel-or iron-based mediators have been detailed in a subsequent study by the same group.…”

Electro‐Synthesis of Organic Compounds with Heterogeneous Catalysis

“…[ 225 ] In addition, indirect cathodic reductions of C=C double bonds have been documented. [ 224 , 226 ] However, all of these techniques use oxidative activation to activate reactants or catalysts, and it is still an unexplored area of research to create electroreductive methods to difunctionalize alkenes. [ 227 ]…”

Electrocatalysis with Molecular Transition-Metal Complexes for Reductive Organic Synthesis

“…Another important challenge is here to reduce the carbonyl to the alcohol in a chemoselective way, avoiding the ketyl radical coupling and the hydrogenation of other unsaturations (e.g., C=C) when present ( Figure 5 b). 48 , 49 To drive carbonyl hydrogenation to the desired selectivity, molecular electrocatalysts have been investigated, 50 , 51 mostly based on Ni, 52 , 53 Fe, 52 , 53 Ru, 54 and Rh 55 − 57 metal complexes, with a body of work using homogeneous and immobilized Rh bipyridine type complexes. 55 − 57 …”

“…In particular, as the standard potentials for carbonyl/alcohol couples are generally close to that of H + /H 2 (e.g., E 0 (acetone/isopropanol) = 0.12 V vs RHE, from ref ), hydrogenations of carbonyl groups do not possess a substantial thermodynamic advantage over hydrogen evolution. Another important challenge is here to reduce the carbonyl to the alcohol in a chemoselective way, avoiding the ketyl radical coupling and the hydrogenation of other unsaturations (e.g., CC) when present (Figure b). , To drive carbonyl hydrogenation to the desired selectivity, molecular electrocatalysts have been investigated, , mostly based on Ni, , Fe, , Ru, and Rh − metal complexes, with a body of work using homogeneous and immobilized Rh bipyridine type complexes. − …”

“…Another important challenge is here to reduce the carbonyl to the alcohol in a chemoselective way, avoiding the ketyl radical coupling and the hydrogenation of other unsaturations (e.g., CC) when present (Figure 5b). 48,49 To drive carbonyl hydrogenation to the desired selectivity, molecular electrocatalysts have been investigated, 50,51 mostly based on Ni, 52,53 Fe, 52,53 Ru, 54 and Rh 55−57 metal complexes, with a body of work using homogeneous and immobilized Rh bipyridine type complexes. 55−57 Recently, Siewert and Fokin disclosed the electrochemical hydrogenation of ketones and aldehydes using a well-defined molecular catalyst based on earth-abundant manganese, namely the binuclear Mn complex [Mn 2 (LH)(CO) 6 Br 2 ] (Figure 5c).…”