Ligand‐Free FeCl₂‐Catalyzed α‐Alkylation of Ketones with Alcohols

Abstract

In this study, we present a facile, cost-effective and expedient hydrogen-borrowing strategy to perform αalkylation of ketones with primary alcohols using FeCl 2 as the catalyst. A set of both ketones and alcohols could be efficiently alkylated to produce their corresponding ketones in good to high yields. 4 5 6 7 8

Recent Advances for Alkylation of Ketones and Secondary Alcohols Using Alcohols in Homogeneous Catalysis

“…At the same year, Yang and co‐workers reported a ligand free FeCl 2 system for α‐alkylation of ketones with primary alcohols (Scheme 37). [41] Benzylic alcohols bearing either electron‐donating or electron‐withdrawing substituents could be efficiently α‐alkylated with substituted acetophenone to give their corresponding ketone products in 60–99% yields. However, 14–23% yields of desired ketones were obtained when aliphatic alcohols were subjected into the ɑ‐alkylation reaction.…”

Structural derivatization strategies of natural phenols by semi-synthesis and total-synthesis

“…As another reduction state of chalcone, dihydrochalcone was always obtained by catalytic hydrogenation of chalcone, while it can also be directly synthesized by catalytic alkylation of ketones. Recently, a ligand-free alkylation of ketones with primary alcohols was developed using FeCl 2 as the catalyst (Scheme 16 e), exhibiting a wide application prospect in rapid synthesis of dihydrochalcones [ 163 ].…”

Polyaniline-Supported Tungsten-Catalyzed α-H Alkylation Reaction of Ketone with Alcohol

“…Noble metals, such as Pd, , Ir, − Ru, Rh, and Ag, were used as catalysts/additives for the process. To reduce the cost of the reaction, cheap metals such as Mn , and Fe were employed to replace noble metals, but expensive Cs additives, high reaction temperature (140–150 °C), and long reaction time (24 h) were usually required. Indeed, for electron-enriched ketones, the reaction may proceed without any metal catalyst, but it still suffers from long reaction time (24 h) and in some cases a lot of alcohol byproducts were inevitably generated .…”

“…In conclusion, W@PANI was found to be an efficient catalyst for α-H alkylation of the ketone with alcohol. In comparison with noble metals, − tungsten is cheap, but the W@PANI-catalyzed reactions did not require harsh reaction conditions like the reactions catalyzed by cheap metals such as Mn , and Fe . The substrate scope was broad, and substrates with both electron-donating and -withdrawing substituents were fit for the reaction, while the reaction time was reduced to 6 h from 24 h .…”

“…In comparison with noble metals, 8−15 tungsten is cheap, but the W@PANI-catalyzed reactions did not require harsh reaction conditions like the reactions catalyzed by cheap metals such as Mn 16,17 and Fe. 18 The substrate scope was broad, and substrates with both electron-donating and -withdrawing substituents were fit for the reaction, while the reaction time was reduced to 6 h from 24 h. 19 Compared with the photocatalytic method, the initial substrate concentration was enhanced to 1 mol/L from 0.05 mol/L. 20 Indeed, the ton-scale synthesis of PANI-supported catalysts has already been achieved by our group in cooperation with companies, making the related materials practical reagents in the future.…”