Reaction scope and mechanistic insights of nickel-catalyzed migratory Suzuki–Miyaura cross-coupling

Abstract

Cross-coupling reactions have developed into powerful approaches for carbon-carbon bond formation. In this work, a Ni-catalyzed migratory Suzuki-Miyaura cross-coupling featuring high benzylic or allylic selectivity has been developed. With this method, unactivated alkyl electrophiles and aryl or vinyl boronic acids can be efficiently transferred to diarylalkane or allylbenzene derivatives under mild conditions. Importantly, unactivated alkyl chlorides can also be successfully used as the coupling partners. To demonstrate the applicability of this method, we showcase that this strategy can serve as a platform for the synthesis of terminal, partially deuterium-labeled molecules from readily accessible starting materials. Experimental studies suggest that migratory cross-coupling products are generated from Ni(0/II) catalytic cycle. Theoretical calculations indicate that the chain-walking occurs at a neutral nickel complex rather than a cationic one. In addition, the original-site cross-coupling products can be obtained by alternating the ligand, wherein the formation of the products has been rationalized by a radical chain process. 1 1234567890():,; Reductive conditions Redox-neutral conditions Redox-neutral conditions Alkyl reagents Metal migration a Migratory cross-coupling of alkyl electrophiles Ni-catalyzed reductive migratory cross-coupling (Zhu and our group): Pd-catalyzed migratory suzuki-miyaura cross-coupling (Sigman): Ni-catalyzed migratory suzuki-miyaura cross-coupling (this work): b c d Fig. 1 Transition metal-catalyzed migratory cross-coupling. a Migratory cross-coupling of alkyl electrophiles. b Ni-catalyzed reductive migratory crosscoupling. c Pd-catalyzed migratory Suzuki-Miyaura cross-coupling. d The approach developed in this study. ARTICLE NATURE COMMUNICATIONS | https://doi.

Synergistic Ni/Cu catalyzed migratory arylsilylation of terminal olefins

“…Based on above results and related literature [42,57], we tentatively proposed a mechanism for this dual metal-catalyzed arylsilylation reaction. As illustrated in Fig.…”

Unexpected Nickel Complex Speciation Unlocks Alternative Pathways for the Reactions of Alkyl Halides with dppf-Nickel(0)

“…Consistent with this proposal, when a prototypical Kumada reaction was carried out in the presence of a 4-methylstyrene additive, 1-(4-methylphenyl)-1phenylethane (16) was also observed (Scheme 5a). We note that nickel-catalyzed migratory Suzuki−Miyaura cross-coupling reactions have been developed by Yin and co-workers 53 and that our reactions share some mechanistic features with such reactions, specifically the formation and recombination of an alkyl radical and the transposition of the nickel center along an alkyl chain. We propose that this results from migratory insertion into a nickel hydride intermediate followed by transmetalation and reductive elimination (Scheme 5b).…”

Mechanistic Insights into the Nickel-Catalyzed Regioselective Carboxylation of Allylic Alcohols

“…In this context, the coupling of allylic alcohol with carbon dioxide represents one of the most attractive methods due to the abundancy, renewability, and the potentially environmental and economic benefits of CO 2 . Typically, the O–H functionalization of allylic alcohol to allylic halide, allylic sulfonate, allylic alkyl ester, , and so forth is necessary in traditional coupling reactions (Scheme A). Fortunately, Sato and co-workers have developed a novel PdCl 2 -catalyzed direct carboxylation of allylic alcohol under mild conditions, using PPh 3 and ZnEt 2 as the ligand and reducing agent, respectively (Scheme B) .…”