Nickel(II)‐Catalyzed Synthesis of Pyrroles from 2H‐Azirines and Activated Ketones

Abstract

Table 1. Reaction of the alkenylfurans ( I ) with ethyl diazoacetate giving oxoalkatrienecarboxylates ( 2 ) and/or 2-(2-furyl)cyclopropanecarboxylates (3). Also quoted are ratios of the rate constants for the addition of diazoacetate to the double bond in the furan ring remotely situated from the alkenyl substituents (KF), to the vinyl group (Kv). and to added cyclohexene (Kc). KF/& and Kv/Kc are each mean values from three experiments. ( 1 ) Catalysis [a] Thermolysis [b] Photolysis [c] -Yield [%] _ _ KF Kv Yield [%] KF Kv R' RZ R3

4,5,6,7-Tetrahydroindol-4-Ones as a Valuable Starting Point for the Synthesis of Polyheterocyclic Structures

“…Ceric (IV) ammonium nitrate (CAN) oxidative coupling of 22 with vinyl ethers 23 affords structural motif 1 and is an attractive strategy toward N- aryl 2,3-unsubstituted tetrahydroindol-4-ones [ 31 ]. Furthermore, azirines are interesting building blocks for pyrroles [ 32 ]. 2H -Azirines 24 are prepared from isoxazoles 25 [ 33 ] or generated in situ from α -azidochalcones 26 [ 34 ].…”

Transition Metal-Mediated Synthesis of Monocyclic Aromatic Heterocycles

“…441 Recently, Suárez extended the scope of this transformation and applied it for the synthesis of bis-glycosylated pyrroles. Thus, the V(V)-catalyzed reaction of 1,3-dicarbonyl compounds (or malonates) 3-415 with 2 H -azirines 3-416 afforded 3-acetylpyrroles 3-417 in good yields.…”

Nickel ferrite nanoparticles: an efficient and reusable nanocatalyst for a neat, one-pot and four-component synthesis of pyrroles

“…11 The investigation of Nickel-catalyzed reactions received great attention recently. 12 However, nickel-catalyzed synthesis of pyrroles has been less studied 13,14 and reports on nickel-catalyzed multicomponent synthesis of pyrroles is rare. 15 Moreover, the reported methods suffer from some drawbacks such as harshness of reaction conditions, long reaction times, expensive catalysts, low yields, irrecoverability of catalysts and the presence of even trace amounts of remaining metal in the end-product.…”