Transition metal-free fluorocyclization of unsaturated N-methoxyamides gives cyclic N-methoxyimidates

Cuzzucoli, Fabio; Racicot, Léanne; Valliant, John F.; Murphy, Graham K.

doi:10.1016/j.tet.2022.132982

Cited by 5 publications

(2 citation statements)

References 33 publications

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“…Hypervalent iodine reagents are readily available mild oxidants that are considered to be environmentally benign alternatives to metal-based oxidants and are widely used in modern organic synthesis. − Their synthetic applications are tremendous and span a wide range of oxidative transformations such as oxidative cyclization/heterocyclization, − difunctionalization of alkenes, − phenol dearomatization, − oxidation of sulfur compounds, , α-functionalization of carbonyl compounds, − and molecular rearrangement reactions. , Hence, they are valuable tools in the synthetic organic chemistry toolbox.…”

Section: Introductionmentioning

confidence: 99%

Toward a General Protocol for Catalytic Oxidative Transformations Using Electrochemically Generated Hypervalent Iodine Species

Elsherbini

Moran

2023

J. Org. Chem.

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A simple catalytic electrosynthetic protocol for oxidative transformations mediated by hypervalent iodine reagents has been developed. In this protocol, electricity drives the iodine(I)/iodine(III) catalytic cycle enabling catalysis with in situ generated hypervalent iodine species, thereby eliminating chemical oxidants and the inevitable chemical waste associated with their mode of action. In addition, no added electrolytic salts are needed in this process. The developed method has been validated using two different hypervalent iodine-mediated transformations: (i) the oxidative cyclization of N-allylic and N-homoallylic amides to the corresponding dihydrooxazole and dihydro-1,3-oxazine derivatives, respectively, and (ii) the α-tosyloxylation of ketones. Both reactions proceeded smoothly under the developed catalytic electrosynthetic conditions without reoptimization, featuring a wide substrate scope and excellent functional group tolerance. In addition, scale-up to gram-scale and catalyst recovery were easily achieved maintaining the high efficiency of the process.

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Section: Introductionmentioning

confidence: 99%

Toward a General Protocol for Catalytic Oxidative Transformations Using Electrochemically Generated Hypervalent Iodine Species

Elsherbini

Moran

2023

J. Org. Chem.

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“…Starting materials amides 1-allyl- N -methoxycyclobutanecarboxamide ( 1a ), 1-allyl- N -methoxycyclohexanecarboxamide ( 1b ), N -methoxy-2,2-dimethylpent-4-enamide ( 1c ), 2-ethyl- N -methoxy-2-methylpent-4-enamide ( 1d ), 2-allyl- N -methoxy-2-methylpent-4-enamide ( 1f ), and N -methoxy-2-vinylbenzamide ( 1m ) were synthesized by using a known literature method, 18 as were N -methoxy-2,2-diphenylpent-4-enamide ( 1e ), 1-allyl- N -ethoxycyclohexanecarboxamide ( 1h ), 19 N -methoxypent-4-enamide ( 1g ), 5i N -ethoxypent-4-enamide ( 1u ), 20 N -(benzyloxy)pent-4-enamide ( 1v ), 5a N -methoxy-2,2-diphenylhex-5-enamide ( 1w ), 21 ( E )- N -methoxy-2,2-diphenylhex-4-enamide ( 1q ), 22 N ,5-dimethoxy-2-vinylbenzamide ( 1y ), 5b N -methoxy-2-phenylpent-4-enamide ( 1z ). 5b Starting material for the synthesis of 2g N -methoxy-2-methyl-pent-4-enamide ( 1n ) 5i .…”

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confidence: 99%

Transition-Metal-Free Selective Halocyclization of N-Alkoxy Amides: Synthesis of N-Alkoxy Lactams and Oximinolactones

Kandukuri,

Manjunath,

Chakave

et al. 2024

Synthesis

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A new method for the synthesis of N-alkoxy lactams and oximinolactones, involving the selective N-cyclization and O-cyclization of unsaturated N-alkoxy amides, is presented. This approach features mild reaction conditions and no requirement for transition-metal catalysts. The protocol demonstrates a wide range of applicability in 5-exo-trig and 6-exo-trig cyclization, accommodating chloro, bromo, and iodo electrophiles. The N-cyclization process can be achieved in the presence of strong lithium base such as LiHMDS or n-BuLi, while the O-cyclization occurs spontaneously without the addition of any base. Mechanistic studies reveal the N-cyclization reactions proceed through cyclic lithium intermediates, as confirmed by FT-IR studies and control experiments, which contribute to the N-selectivity. The current methodology was successfully used in synthesis of natural product (E/Z) des-hydroxy triticone A and B.

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Iron-catalyzed group-transfer reactions with iodine(III) reagents

Casitas,

Andreetta

2024

Advances in Catalysis

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Transition metal-free fluorocyclization of unsaturated N-methoxyamides gives cyclic N-methoxyimidates

Cited by 5 publications

References 33 publications

Toward a General Protocol for Catalytic Oxidative Transformations Using Electrochemically Generated Hypervalent Iodine Species

Toward a General Protocol for Catalytic Oxidative Transformations Using Electrochemically Generated Hypervalent Iodine Species

Transition-Metal-Free Selective Halocyclization of N-Alkoxy Amides: Synthesis of N-Alkoxy Lactams and Oximinolactones

Iron-catalyzed group-transfer reactions with iodine(III) reagents

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