Redox-Neutral Nickel-Catalyzed Cross-Coupling Reactions of (Homo)allylic Alcohols and Aryltriflates

Abstract

Herein, we report a redox-neutral Ni-catalyzed cross-coupling reaction of two readily available precursors to produce the corresponding ketones that are an important structural motif in numerous biologically active entities. By the use of a commercially available nickel/Triphos catalytic system, a range of easily accessible alkenyl primary alcohols and aryltriflates can be converted in a rapidly assembled fashion to valuable ketones with good yields and wide functional group tolerance. We also demonstrate the utility of this transformation by late-stage functionalization of a large set of complex molecules with good efficiency, which offers a distinct entry to more functionalized aromatic ketones.

Nickel-Catalyzed Isomerization/Allylic Cyanation of Alkenyl Alcohols

“…Remote functionalization mediated by alkene isomerization is a powerful strategy for the construction of valuable molecules from readily available materials. − In this content, alkenyl alcohols are considered as versatile substrates for these transformations. The isomerization of alkenyl alcohols to ketones through olefin migration has been catalyzed by using various metals including Pd 6 , Rh 7 , Ru 8 , and Fe 9 .…”

Conversion of Primary Alcohols and Butadiene to Branched Ketones via Merged Transfer Hydrogenative Carbonyl Addition–Redox Isomerization Catalyzed by Rhodium

“…Preexisting methods of this type include hydroacylation (which typically requires β-chelating groups to suppress decarbonylation), , “oxa-Heck” reactions (which are restricted to aryl transfer), − two reports of the reductive coupling of styrenes with anhydrides, , and, finally, recently reported formate-mediated reductive coupling–redox isomerizations of aldehydes and vinyl halides or triflates . Here, we report a method for the direct redox–neutral conversion of primary benzylic or aliphatic alcohols and butadiene (12 × 10 6 tons/year) to branched ketones via merged transfer hydrogenative carbonyl addition–redox isomerization. − These processes represent the first examples of rhodium-catalyzed carbonyl addition via hydrogen autotransfer. , …”

Redox-neutral dehydrogenative cross-coupling of alcohols and amines enabled by nickel catalysis

“…Recently, our group have developed a redox-neutral Ni-catalyzed cross-coupling reaction of (homo)allylic alcohols and aryltriflates to produce ketones using commercially available nickel/Triphos catalytic system. 13 As part of our group's continuous interest, herein, we describe another Ni catalysis bearing N-heterocyclic carbene (NHC) as the ligand for the direct amidation of saturated or unsaturated alcohols 14 with amines without the need for external oxidants (Scheme 1d).…”