Catalyst-Free and Transition-Metal-Free Approach to 1,2-Diketones via Aerobic Alkyne Oxidation

This study investigates a synthetic sequence for the preparation of 1,2-diketone products. The sequence avoids oxidative conditions and instead employs reliable transformations including the Horner−Wadsworth−Emmons and addition of Grignard reagents to N-methyl-N-methoxy (Weinreb) amide intermediates. The reaction sequence is suitable for the synthesis of nonsymmetric aliphatic and aryl substituted derivatives.1,2-Dicarbonyl derivatives, including α-ketoacids, -esters, and -amides as well as 1,2-diketones, are widely found in nature and have recognized biological activities. 1−7 Additionally, 1,2dicarbonyl substrates serve as versatile precursors that are commonly used in the preparation of valuable intermediates and downstream products. For example, recent advances in modern organic photochemistry have exploited α-ketoacids as precursors for carbonyl radical species 8,9 and 1,2-dicarbonyl substrates remain central to classic condensation strategies for the construction of aromatic heterocycles including imidazoles, 10−13 pyrazines, 14,15 1,2,4-triazines, 16 quinoxalines, 17,18 and other 1,4-diazine derivatives. 19

show abstract

“…Data for 15b : TLC (2% EtOAc in hexanes): R f : 0.48 (UV/CAM). Spectral data for diketone 15b are in agreement with published data …”

Section: Methodssupporting

confidence: 89%

A Nonoxidative Sequence for the Preparation of 1,2-Diketone Derivatives Using Aldehyde and Organometallic Building Blocks

2022

View full text Add to dashboard Cite

show abstract

“…When NFSI (1.5 equiv) was used as fluorinating agent, only the hydrated product 2 a was isolated under the same reaction conditions (Table 1, entry 15). Surprisingly, the prevalent formation of the α,α-difluoro β-phthalimido ketones 4 a could occur when the gold(III) species PicAuCl 2 or NaAuCl 4 • 2H 2 O were employed as the catalytic system (Table 1, entries [16][17][18][19][20][21][22]. Under the presence of the Au[III] catalyst the 3 a/4 a ratio depended on the quantity of Selectfluor (Table 1, entries 17-21), the reaction temperature (Table 1, entries 19-21) and on the feature of the reaction medium (Table 1, entries 21-23).…”

Section: Resultsmentioning

confidence: 99%

“…3) and with the catalyst free and transition‐metal free one promoted by K 2 S 2 O 8 (Scheme 6, Eq. 3) [16] …”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Gold‐Catalyzed Regioselective Oxyfluorination/Oxydifluorination vs. Diketonization of Phthalimido‐Protected Propargylamines with Selectfluor

2022

View full text Add to dashboard Cite

Alkyl‐ and aryl‐substituted N‐propargyl phthalimides were used as valuable building blocks for the selective formation of the corresponding α‐fluoro, β‐phthalimido ketones, α,α‐difluoro, β‐phthalimido ketones or β‐phthalimido α‐diketones by means of gold‐catalyzed oxyfluorination/oxydifluorination or dioxygenation reactions. The key factors addressing the product selectivity control were determined. The simultaneous assembly of the quinoxaline nucleus and the removal of the phthalimido‐protecting group were tested. Reaction mechanisms of the different reaction pathways are assumed.

show abstract

“…Due to these applications, various methods have been reported in literature for the synthesis of 1,2‐dicarbonyl compounds by using a wide variety of transition metal catalysts. Apart from transition metal catalysis, catalyst‐free organic approaches have also been reported for the synthesis of 1,2‐diketones by using strong oxidants such as KMnO 4 , [11] Hg(NO 3 ) 2 , [12] OsO 4 , [13] potassium persulfate (K 2 S 2 O 8 ), [14] organic peracids, [15] bases, [16] and Lewis acids [17] . In addition, photocatalyzed oxidation of internal alkynes to 1,2‐diketones by using dioxygen or air as an oxidant was also reported [18]…”

Section: Introductionmentioning

confidence: 99%

Transition Metal‐Catalyzed Synthesis of 1,2‐Diketones: An Overview

Kumar

Sridharan

2021

Asian J Org Chem

View full text Add to dashboard Cite

The 1,2-diketone structural motif is present in various natural products and compounds of biological significance. In addition, these compounds are frequently used as precursors or intermediates in several synthetically important organic transformations. The transition-metal catalysis plays an essential role for the generation of several carbon-carbon and carbon-heteroatom bonds to access diverse heterocyclic compounds. This metal-catalyzed approach has been frequently used for the synthesis of these valuable 1,2-diketones. This review summarizes the various approaches involving the transition metal-catalyzed synthesis of 1,2-diketones from easily accessible staring materials.

show abstract

Catalyst-Free and Transition-Metal-Free Approach to 1,2-Diketones via Aerobic Alkyne Oxidation

Cited by 26 publications

References 47 publications

A Nonoxidative Sequence for the Preparation of 1,2-Diketone Derivatives Using Aldehyde and Organometallic Building Blocks

A Nonoxidative Sequence for the Preparation of 1,2-Diketone Derivatives Using Aldehyde and Organometallic Building Blocks

Gold‐Catalyzed Regioselective Oxyfluorination/Oxydifluorination vs. Diketonization of Phthalimido‐Protected Propargylamines with Selectfluor

Transition Metal‐Catalyzed Synthesis of 1,2‐Diketones: An Overview

Contact Info

Product

Resources

About