Copper‐Catalyzed <i>N</i>‐Aryl‐β‐enaminonitrile Synthesis Utilizing Isocyanides as the Nitrogen Source

Kim, Seoksun; Hong, Soon Hyeok

doi:10.1002/adsc.201400973

“…Another Cu I ‐catalyzed alkoxyimidoylation/condensation cascade reaction was reported by Kim and Hong (Scheme ) . The in situ formed formimidate intermediate 123 condenses with the α‐acidic arylacetonitrile ( 120 ), affording 3‐amino‐2‐arylacrylonitriles ( 121 ) in moderate to excellent yields.…”

Section: Insertions Of Isocyanides Into Heteroatom–metal Bondsmentioning

confidence: 73%

Base Metal Catalyzed Isocyanide Insertions

Collet

¹

,

Roose

²

,

Ruijter

³

et al. 2019

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Isocyanides are diverse C1 building blocks considering their potential to react with nucleophiles, electrophiles, and radicals. Therefore, perhaps not surprisingly, isocyanides are highly valuable as inputs for multicomponent reactions (MCRs) and other one‐pot cascade processes. In the field of organometallic chemistry, isocyanides typically serve as ligands for transition metals. The coordination of isocyanides to metal centers alters the electronic distribution of the isocyano moiety, and reaction pathways can therefore be accessed that are not possible in the absence of the metal. The tunable reactivity of the isocyanide functional group by transition metals has evolved into numerous useful applications. Especially palladium‐catalyzed isocyanide insertion processes have emerged as powerful reactions in the past decade. However, reports on the use of earth‐abundant and cheap base metals in these types of transformations are scarce and have received far less attention. In this Minireview, we focus on these emerging base metal catalyzed reactions and highlight their potential in synthetic organic chemistry. Although mechanistic studies are still scarce, we discuss distinct proposed catalytic cycles and categorize the literature according to 1) the (hetero)atom bound to and 2) the type of bonding with the transition metal in which the (formal) insertion occurs.

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“…Another Cu I -catalyzed alkoxyimidoylation/condensation cascade reaction was reported by Kim and Hong (Scheme 31). [59] Theinsitu formed formimidate intermediate 123 condenses with the a-acidic arylacetonitrile (120), affording 3-amino-2-arylacrylonitriles (121)i nm oderate to excellent yields.…”

Section: Angewandte Chemiementioning

confidence: 99%

Base Metal Catalyzed Isocyanide Insertions

Collet

¹

,

Roose

²

,

Ruijter

³

et al. 2019

View full text Add to dashboard Cite

Isocyanides are diverse C1 building blocks considering their potential to react with nucleophiles, electrophiles, and radicals. Therefore, perhaps not surprisingly, isocyanides are highly valuable as inputs for multicomponent reactions (MCRs) and other one‐pot cascade processes. In the field of organometallic chemistry, isocyanides typically serve as ligands for transition metals. The coordination of isocyanides to metal centers alters the electronic distribution of the isocyano moiety, and reaction pathways can therefore be accessed that are not possible in the absence of the metal. The tunable reactivity of the isocyanide functional group by transition metals has evolved into numerous useful applications. Especially palladium‐catalyzed isocyanide insertion processes have emerged as powerful reactions in the past decade. However, reports on the use of earth‐abundant and cheap base metals in these types of transformations are scarce and have received far less attention. In this Minireview, we focus on these emerging base metal catalyzed reactions and highlight their potential in synthetic organic chemistry. Although mechanistic studies are still scarce, we discuss distinct proposed catalytic cycles and categorize the literature according to 1) the (hetero)atom bound to and 2) the type of bonding with the transition metal in which the (formal) insertion occurs.

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“…This unusual behavior is probably aresult of the propensity of the amide group to form hydrogen bonds. [18] It is worth noting that, in addition to the acyclic active methylene compounds,c yclic substrates were also capable reacting using this protocol, and afforded the corresponding products (3p-r)i nn early quantitative yields.A lthough it is al ittle discouraging that the benzyl cyanide,acompound successfully utilized in Hongs work, [17] did not result in the desired product 3s (benzyl cyanide was recovered), this result clearly suggested ad ifferent mechanism is operative in the 3 30 mol %1 ,4-dioxane 92 6A g 2 CO 3 10 mol %1 ,4-dioxane 48 (52) [c] 7P d(OAc) 2 30 mol %1 ,4-dioxane 0 [d] 8C uI 30 mol %1 ,4-dioxane 0 [d] 9M n(OAc) 3 30 mol %1 ,4-Dioxane 0 [ Angewandte current silver-catalyzed reaction. Later, the substrate scope of this reaction was extended to other aromatic isocyanides without difficulty.T he electronic properties of the aromatic rings had no influence on either the stereoselectivities or yields of the products 3aa-ak,although use of 2-isocyano-9Hfluorene resulted in as light decrease in the yield of corresponding product (3ak).…”

mentioning

confidence: 98%

Silver‐Catalyzed Cross‐Coupling of Isocyanides and Active Methylene Compounds by a Radical Process

Liu

¹

,

Liu

²

,

Liao

³

et al. 2015

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Isocyanides are versatile building blocks, and have been extensively exploited in C-H functionalization reactions. However, transition-metal-catalyzed direct C-H functionalization reactions with isocyanides suffer from over-insertion of isocyanides. Reported herein is a radical coupling/isomerization strategy for the cross-coupling of isocyanides with active methylene compounds through silver-catalysis. The method solves the over-insertion issue and affords a variety of otherwise difficult to synthesize β-aminoenones and tricarbonylmethanes under base- and ligand-free conditions. This report presents a new fundamental C-C bond-forming reaction of two basic chemicals.

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Copper‐Catalyzed N‐Aryl‐β‐enaminonitrile Synthesis Utilizing Isocyanides as the Nitrogen Source

Cited by 32 publications

References 72 publications

Base Metal Catalyzed Isocyanide Insertions

Base Metal Catalyzed Isocyanide Insertions

Base Metal Catalyzed Isocyanide Insertions

Silver‐Catalyzed Cross‐Coupling of Isocyanides and Active Methylene Compounds by a Radical Process

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