Iridium‐Catalyzed Direct Dehydroxylation of Alcohols

Abstract

Iridium‐catalyzed direct dehydroxylation of alcohols with hydrazine was developed through a combination of the oxidation of alcohols and the Wolff–Kishner reduction. This protocol is simple to perform and highly efficient for a series of primary, benzylic and allylic alcohols.

Experimental and Theoretical Mechanistic Investigation of the Iridium-Catalyzed Dehydrogenative Decarbonylation of Primary Alcohols

“…It has previously been observed that Vaska's complex does not dehydrogenate an alcohol without the presence of a strong base. 34 These results again illustrate that monodentate phosphine ligands are less effective in the dehydrogenation cycle.…”

Palladium nanoparticles supported on reduced graphene oxide as an efficient catalyst for the reduction of benzyl alcohol compounds

“…For example, benzyl alcohol was reduced in 54% yield after 3 h using Pd/C catalyst in compressed CO 2 /water and 1 MPa H 2 [4]. Independently, Huang et al [5] obtained toluene in 98% yield through the reduction of benzyl alcohol using iridium catalyst with hydrazine at 160°C after 3 h. Wang et al [6] reported benzyl alcohol hydrogenolysis in 99% yield using PdCl 2 and PMHS after 12 h at 40°C.…”

“…It should be noted that this procedure allowed the reduction of benzyl alcohol derivatives in relatively short reaction times and mild conditions as compared to the methods described in the literature [4][5][6]. For example, benzyl alcohol was reduced in 54% yield after 3 h using Pd/C catalyst in compressed CO 2 /water and 1 MPa H 2 [4].…”

“…Since hydroxyl group is a poor leaving group, its transformation into a good leaving group is generally employed [3]. Several reagents and catalysts have been reported for the reduction of benzyl alcohols [4][5][6]. For example, Pd/C and H 2 in compressed CO 2 /water [4], iridium catalyst with hydrazine at 160°C [5], palladium chloride (PdCl 2 ) and polymethylhydrosiloxane (PMHS) as hydride source [6] have been investigated for this chemical transformation.…”

Ruthenium(ii)-catalyzed olefinationviacarbonyl reductive cross-coupling

“…Very recently, we have disclosed a ruthenium-catalyzed deoxygenation reaction for the highly selective cleavage of aliphatic primary C–O bonds. 10 Building on the similar ruthenium( ii ) catalysis, we further demonstrated its robustness in catalyzing a series of new carbon–carbon bond forming processes through addition reactions to various carbonyl compounds, imines and activated alkenes. 11 – 13 Variations of these precedents notwithstanding, one of their commonalities is to use aldehydes/ketones as alkyl carbanion equivalents via hydrazone formation.…”