Pd‐Catalyzed Hydrogen‐Transfer Reactions from Alcohols to C=C, C=O, and C=N Bonds

Abstract

This review covers Pd‐catalyzed abstracting and borrowing hydrogen transfers from alcohols to C=C, C=O, and C=N bonds. An abstracting hydrogen transfer implies a reaction in which an alcohol serves only as a hydrogen atom source, whereas in a borrowing hydrogen transfer the alcohol is part of the final product. Both transfer types involve a palladium monohydride or palladium dihydride, and are implicated in a variety of useful and safe one‐pot reactions such as the formation, with low quantities of waste material, of C–C, C–O, and C–N bonds. Plausible mechanisms are, as far as possible, provided.

Hydrogen Transfer Reactions of Carbonyls, Alkynes, and Alkenes with Noble Metals in the Presence of Alcohols/Ethers and Amines as Hydrogen Donors

“…Several homogeneous counterparts such as Pd(OAc) 2 , [PdCl 2 (PPh 3 ) 2 ] and [Pd 2 (dba) 3 ] (dba = dibenzalacetone) were tested, but showed no conversion, indicating that the catalytic activity is linked to the pincer complexes, and not to palladium colloids [93]. The dominance of the noble metal-catalyzed hydrogen transfer reactions towards homogeneous catalysis can be seen clearly; nevertheless, interesting achievements based on heterogeneous catalysis (supported metals or immobilized homogeneous representatives) were presented as well in the literature [29,94].…”

“…The dominance of the noble metal-catalyzed hydrogen transfer reactions towards homogeneous catalysis can be seen clearly; nevertheless, interesting achievements based on heterogeneous catalysis (supported metals or immobilized homogeneous representatives) were presented as well in the literature [29,94].…”

Secondary Phosphine Oxides as Multitalented Preligands En Route to the Chemoselective Palladium‐Catalyzed Oxidation of Alcohols

“…Alternatively, oxidizing alcohols in the absence of any formal reoxidant necessarily implies metal‐mediated hydrogen transfers from the substrate to a hydrogen acceptor such as electron‐poor alkenes . This approach was recently termed “abstracting‐hydrogen methodology” (AHM) (Scheme , pathway b). Surprisingly, scarce literature precedent in which this combination has convincingly been used proves that such a synergism remains to be harnessed.…”

Conversion of Stearic Acid into Bio-Gasoline over Pd/ZSM-5 Catalysts with Enhanced Accessibility

“…In this way, Pd is known to present activity in the oligomerization and polymerization of olefins [40][41][42][43], which would be in agreement with its participation also in olefin oligomerization reactions. Moreover, Pd exhibits hydrogen transfer activity, which could favor the aromatization step in the OCA pathway [44][45][46][47].…”