Manganese(I)-catalyzed asymmetric (transfer) hydrogenation of ketones: An insight into the effect of chiral PNN and NN ligands

Novel Metallomacrocyclic Carboxamide Mn(II) Complexes as Efficient Catalysts for the Transfer Hydrogenation of Ketones

“…Thus, in sustainable transfer hydrogenation reactions, the use of a nonhazardous and cheaper sources of hydrogen is of importance. Recently, less toxic and more readily available hydrogen sources, [22,[55][56][57][58] such as formic acid [59][60][61] and sodium formate in water [62][63][64] have been used with promising outcomes. For TH reactions, isopropanol has been the conventional source of hydrogen for a long time, although it is relatively expensive.…”

“…[15][16][17] Since the pioneering work of Beller and co-workers, Mn(I) catalysed transfer hydrogenation reactions have attracted significant attention. [18][19][20][21][22] This is due to the high catalytic efficiency of these Mn(I) catalysts in the reduction of a wide range of unsaturated substrates such as ketones, aldehydes, olefins, nitriles, imines among others. [23][24][25][26][27] For example, Kundu and co-workers recently reported the use of benzimidazoleamine Mn(I) tricarbonyl catalysts for the transfer hydrogenation of ketones and imines.…”

“…Since the pioneering work of Beller and co‐workers, Mn(I) catalysed transfer hydrogenation reactions have attracted significant attention [18–22] . This is due to the high catalytic efficiency of these Mn(I) catalysts in the reduction of a wide range of unsaturated substrates such as ketones, aldehydes, olefins, nitriles, imines among others [23–27] .…”

Enantioselective synthesis of chiral β-hydroxy sulfonesviamanganese catalyzed asymmetric hydrogenation

“…18 In 2017, Clarke and coworkers reported the first example of manganese-asymmetric catalytic hydrogenation of aryl alkyl ketones with pyridine-based chiral PNN tridentate ligands, although substrate limitation was observed in this reaction. 19 Soon afterwards, Beller, 20 Mezzetti, 21 Ding, 22 Zhang, 23 Morris, 24 Liu, 25 and Sun 26 also reported different chiral manganese catalysts for AH reactions to construct chiral alcohols and amines. Meanwhile, our group developed various imidazole-based PNN tridentate ferrocene ligands and successfully applied them in the manganese-catalyzed AH of unsymmetrical benzophenones, aryl alkyl ketones, and α,β-unsaturated ketones with excellent activities and high enantioselectivities.…”

Selective Transfer Hydrogenation of C=O and Conjugated C=C Bonds Using An NHC‐Based Pincer (CNC)MnI Complex in Methanol**

“…[16,[20][21][22] Recently, few catalytic systems with precious transition metal complexes of Rh I , Ir III and Ru II were developed for the transfer hydrogenation of aldehydes and ketones using methanol. [23][24][25][26][27][28][29] Although, employing isopropanol several Mn I complexes were explored towards the transfer hydrogenation of carbonyl compounds, [30][31][32][33][34][35][36] Mn I complex catalyzed utilization of methanol for the transfer hydrogenation reactions has not yet been reported.…”