Coupling of amides with ketones via C-N/C-H bond cleavage: a mild synthesis of 1,3-diketones (original) (raw)
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The Journal of Organic Chemistry, 2019
Conversion of a wide range of N-Boc amides into aryl ketones was achieved with Grignard reagents via chemoselective C(O)-N bond cleavage. The reactions proceeded under catalyst-free condition with different aryl, alkyl and alkynyl Grignard reagents. α-Ketoamide was successfully converted into aryl diketones while α,β-unsaturated amide undergoes 1,4-addition followed by C(O)-N bond cleavage to provide diaryl propiophenones. N-Boc amides displayed higher reactivity than Weinreb amides with Grignard reagents. Broad substrate scope, excellent yields and quick conversion are important features of this methodology.
Amide/Ester Cross-Coupling via C−N/C−H Bond Cleavage: Synthesis of β-Ketoesters
Chen, J.; Joseph, D.; Xia, Y.; Lee, S. J. Org. Chem. 2021, 86(8), 5943-5953., 2021
Activated primary, secondary, and tertiary amides were coupled with enolizable esters in the presence of LiHMDS to obtain good yields of β-ketoesters at room temperature. Notably, this protocol provides an efficient, mild, and high chemoselectivity method to synthesis of β-alkylketoesters using the cross-coupling between aliphatic amides and esters. Meanwhile, gram-scale secondary and primary amides reacted via in situ generated activated tertiary amides and exhibited good reactivity when coupled with esters.
2004
Highly Diastereoselective Synthesis of b-Hydroxy Amides Giu eppe Bartoli,*a Marcella Bosco,a Enrico Marcantoni,b Massimo Massaccesi,a Samuele Rinaldi,c Letizia Sambria a Dipartimento di Chimica Organica ‘A. Mangini’, v. le Risorgimento 4, 40136 Bologna, Italy Fax +39(51)2093654; E-mail: giuseppe.bartoli@unibo.it b Dipartimento di Scienze Chimiche, Università di Camerino, v. S. Agostino 1, 62032 Camerino (MC), Italy c Dipartimento di Scienze e Materiali della Terra, Università di Ancona, v. Brecce Bianche, 60131 Ancona, Italy Received 1 June 2004
N,N-Dialkyl Amides as Versatile Synthons for Synthesis of Heterocycles and Acyclic Systems
Organic Synthesis - A Nascent Relook [Working Title]
N,N-Dialkyl amides such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), are common polar solvents, finds application as a multipurpose reagent in synthetic organic chemistry. They are cheap, readily available and versatile synthons that can be used in a variety of ways to generate different functional groups. In recent years, many publications showcasing, excellent and useful applications of N,N-dialkyl amides in amination (R-NMe 2), formylation (R-CHO), as a single carbon source (R-C), methylene group (R-CH 2), cyanation (R-CN), amidoalkylation (-R), aminocarbonylation (R-CONMe 2), carbonylation (R-CO) and heterocycle synthesis appeared. This chapter highlights important developments in the employment of N,N-dialkyl amides in the synthesis of heterocycles and functionalization of acyclic systems. Although some review articles covered the application of DMF and/or DMA in organic functional group transformations, there is no specialized review on their application in the synthesis of cyclic and acyclic systems.
Amides Activation: Transition Metal-Free Coupling Between C N Activated Amides and Enolizable Amides
Joseoph, D.; Oh, M. S.; Jayaraman, A.; Lee, S. Bull. Korean Chem. Soc. 2021, 42(10), 1293-1295, 2021
Transition metal-free Claisen-type condensation between two different amides was developed. N-phenyl-Ntosylbenzamide derivatives reacted with enolizable amides such as N-methyl pyrrolidinone and N,N-dimethyl acetamide in the presence of NaHMDS to give their corresponding β-ketoamides with moderate-to-good yields.
Palladium-Catalyzed Amide N−C Hiyama Cross-Coupling: Synthesis of Ketones
Idris, M. A.; Lee, S. Org. Lett. 2020, 22(23), 9190-9195., 2020
N-Acylglutarimides and arylsiloxanes reacted in the presence of Pd(OAc) 2 /PCy 3 , Et 3 N•3HF, and LiOAc to provide the corresponding arylketones in good yields. Aryl-, vinyl-, and alkylsubstituted N-acylglutarimides showed good activity in the coupling reactions of arylsiloxanes. The reaction had a broad substrate scope and showed good functional group tolerance. N-Benzoylsuccinimide and Nprotected N-phenylbenzamides showed good activities in coupling reactions with phenylsiloxane. The employment of CuF 2 as an activor afforded the decarbonylative products at 160°C.
A facile preparation of various N-heterocycles using amides and olefins
Tetrahedron Letters, 2014
We herein report a one pot approach for the synthesis of various nitrogen containing heterocycles including: oxazolines, thiazolines, and dihydro dioxazines via the addition of amides to olefins in the presence of N-iodosuccinimide (NIS) and propionitrile at high temperatures. Thus, the reaction of aryl/heteroaryl amides, thioamides, N-hydroxybenzamide, and phenylurea with various olefins in the presence of NIS and propionitrile at 45°C afforded the N-heterocycles in good to moderate yields. Reaction of the electron deficient triO -acetyl-D-glucal and triO -acetyl-D-galactal with benzamide and thiophene-2-carboxamide afforded the N-glycooxazolines in good yields. The newly made heterocycles were tested against various enzymes. Only 3,6-diphenyl-dihydro-1,4,2-dioxazine (1c) was found to moderately inhibit hexokinase II (hHK2).
Tetrahedron, 2012
An efficient sodium bicarbonate promoted aerobic oxidation reaction to prepare N-monosubstituted aketo amides in the presence of n-tetrabutylammonium hydrogensulfate (TBAHS) was described. This reaction provides a very simple and convenient synthetic route to N-monosubstituted a-keto amides from easily available aryl-or heteroarylacetamides in good to high yields without using toxic reagents and harsh conditions.