Polystyrene Supported Pyrazole-based Palladium Catalysts/Precatalysts for Acceptorless Dehydrogenative Coupling of Alcohols in Water

Accessing 2‐Aryl Quinolines via Acceptorless Dehydrogenation and Transfer Hydrogenation Under Base and Solvent‐Free Reaction Conditions

“…In the last decade, acceptorless dehydrogenation, borrowing hydrogen, and transfer hydrogenation strategies have gained popularity to overcome these challenges [15,16] . Owing to this, there are numerous reports on acceptorless dehydrogenative synthesis of quinolines utilizing homogenous catalytic system involving metals such as Co, [17] Cu, [18] Ir, [19] Fe, [20] Mn, [21] Ni, [22] Re, [23] Ru, [24] Zn, [25] and heterogeneous catalyst such as Co on C 3 N 4 , [26] CuO, [27] CuNiFeO, [28] Fe 2 O 3 , [29] CoFe 2 O 4 , [30] Ir on mesoporous silica, [31a] porous organic polymer supported Ir catalyst, [31b] covalent triazine framework supported Ir complex, [31c] Pd on polymer support [32] . However, the synthesis of quinoline via transfer hydrogenation strategy remains less explored [33–36] .…”

“…[15,16] Owing to this, there are numerous reports on acceptorless dehydrogenative synthesis of quinolines utilizing homogenous catalytic system involving metals such as Co, [17] Cu, [18] Ir, [19] Fe, [20] Mn, [21] Ni, [22] Re, [23] Ru, [24] Zn, [25] and heterogeneous catalyst such as Co on C 3 N 4 , [26] CuO, [27] CuNiFeO, [28] Fe 2 O 3 , [29] CoFe 2 O 4 , [30] Ir on mesoporous silica, [31a] porous organic polymer supported Ir catalyst, [31b] covalent triazine framework supported Ir complex, [31c] Pd on polymer support. [32] However, the synthesis of quinoline via transfer hydrogenation strategy remains less explored. [33][34][35][36] In the literature we found only a few reports where Ru, [37] Ir, [19] Ni, [22] Fe [38] homogeneous systems and CuNiFeO [28] heterogeneous catalytic systems were employed for the synthesis of quinoline derivatives using 2-nitrobenzyl alcohol as starting materials via transfer hydrogenation strategy.…”