Reductive Alkylation of Alkenyl Acetates with Alkyl Bromides by Nickel Catalysis

He, Rong-De; Bai, Ya Mei; Han, Guan-Yu; Zhao, Zhenzhen; Pang, Xiaoyang; Pan, Xiaobo; Liu, Xueyuan; Shu, Xing‐Zhong

doi:10.1002/anie.202114556

Cited by 34 publications

(14 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results presumably suggest that L1 Ni 0 , ( L1 )INi II Ar, or ( L1 )Ni I Ar species were not involved in the catalytic cycle, which is also very different from our previous works . However, when the [( L1 )Ni I Cl] 2 catalyst was utilized, the target product can be obtained in 25% yield, which supports that the reaction was initiated with ( L1 )Ni I Br species, rather than the L1 Ni 0 catalyst as before. As anticipated, the model reaction with this [( L1 )Ni I Cl] 2 catalyst can proceed smoothly to give product 3 in 81% yield.…”

contrasting

confidence: 57%

Deoxygenative Arylboration of Aldehydes via Copper and Nickel/Photoredox Catalysis

Zheng

Wang

et al. 2022

ACS Catal.

View full text Add to dashboard Cite

Deoxygenative difunctionalization of carbonyls represents a convenient route to construct complex molecules considering the readily available aldehyde and ketone compounds. The present approaches typically rely on strategies via carbene, carbanion, or carbocation equivalents. Herein, combined with dual nickel/photoredox catalysis regime, we developed a strategy through a radical intermediate to achieve the deoxygenative arylboration of aldehydes. Compared with the known patterns of carbon−oxygen (C−O) bond transformations, this coupling of C-OBPin unit opens a direction for this chemistry. A wide variety of substrates bearing a diverse set of functional groups were compatible with this method under very mild conditions (visible light, ambient temperature, no strong base) to afford the benzylic boronic esters, which have important versatilities in organic synthesis.

show abstract

contrasting

confidence: 57%

Deoxygenative Arylboration of Aldehydes via Copper and Nickel/Photoredox Catalysis

Zheng

Wang

et al. 2022

ACS Catal.

View full text Add to dashboard Cite

show abstract

“…Further studies established that the combination of nickel and Zn enables the coupling of alkenyl acetates with alkyl bromides (Scheme ). The reaction proceeds under very mild conditions and tolerates various functionalities, including groups that are sensitive to Grignard reagents (e.g., alkyl–Cl, RCON–H, R–CN, and RCHO). Primary, secondary, cyclic, and acyclic alkyl bromides all worked well.…”

Section: Reductive Alkylation Of Alkenyl Acetatesmentioning

confidence: 99%

Reductive Cross-Coupling of Unreactive Electrophiles

2022

Self Cite

View full text Add to dashboard Cite

Metrics & MoreArticle Recommendations CONSPECTUS: Transition-metal-catalyzed reductive coupling of electrophiles has emerged as a powerful tool for the construction of molecules. While major achievements have been made in the field of cross-couplings between organic halides and pseudohalides, an increasing number of reports demonstrates reactions involving more readily available, low-cost, and stable, but unreactive electrophiles. This account summarizes the recent results in our laboratory focusing on this topic. These findings typically include deoxygenative C−C coupling of alcohols, reductive alkylation of alkenyl acetates, reductive C−Si coupling of chlorosilanes, and reductive C−Ge coupling of chlorogermanes.The reductive deoxygenative coupling of alcohols with electrophiles is synthetically appealing, but the potential of this chemistry remains to be disclosed. Our initial study focused on the reaction of allylic alcohols and aryl bromides by the combination of nickel and Lewis acid catalysis. This method offers a selectivity that is opposite to that of the classic Tsuji−Trost reactions. Further investigation on the reaction of benzylic alcohols led to the foundation of a dynamic kinetic cross-coupling strategy with applications in the nickelcatalyzed reductive arylation of benzylic alcohols and cobalt-catalyzed enantiospecific reductive alkenylation of allylic alcohols. The titanium catalysis was later established to produce carbon radicals directly from unactivated tertiary alcohols via C−OH cleavage.The development of their coupling reactions with carbon fragments delivers new methods for the construction of all-carbon quaternary centers. These reactions have shown high selectivity for the functionalization of tertiary alcohols, leaving primary and secondary alcohols intact. Alkenyl acetates are inexpensive, stable, and environmentally friendly and are considered the most attractive alkenyl reagents. The development of reductive alkylation of alkenyl acetates with benzyl ammoniums and alkyl bromides offers mild approaches for the conversion of ketones into aliphatic alkenes. Extensive studies in this field have enabled us to extend the cross-electrophile coupling from carbon to silicon and germanium chemistry. These reactions harness the ready availability of chlorosilanes and chlorogermanes but suffer from the challenge of their low reactivity toward transition metals. Under reductive nickel catalysis, a broad range of alkenyl and aryl electrophiles couple well with vinyl-and hydrochlorosilanes. The use of alkyl halides as coupling partners led to the formation of functionalized alkylsilanes. The C−Ge coupling seems less substrate-dependent, and various common chlorogermanes couple well with aryl, alkenyl, and alkyl electrophiles. In general, functionalities such as Grignard-sensitive groups (e.g., acid, amide, alcohol, ketone, and ester), acid-sensitive groups (e.g., ketal and THP protection), alkyl fluoride and chloride, aryl bromide, alkyl tosylate and mesylate, silyl ether, and amine are tolerated. ...

show abstract

“…Shu and co-workers demonstrated that alkenyl acetates can be engaged in sp 2 –sp 3 XEC with alkyl bromides, unlocking a previously inaccessible mode of reactivity (Scheme A). Oxidative addition across the C–O bond continues to present challenges due to the lack of reactivity demonstrated by unactivated alkenyl acetates.…”

Section: Part 3 Ni Catalysismentioning

confidence: 99%