Microwave-Accelerated Solvent-Free Synthesis of Thioketones, Thiolactones, Thioamides, Thionoesters, and Thioflavonoids

Varma, Rajender S.; Kumar, Dalip

doi:10.1021/ol990629a

Cited by 133 publications

(71 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This reaction is believed to proceed via silver-mediated hydroamination of the triple bond of propargyl bromide (17, Scheme 3), followed by nucleophilic substitution via the enaminone functionality (18). Rearrangement of the cyclic enamine intermediate 19 would www.eurjoc.org afford the thermodynamically more stable N-bridgehead pyrrole 20.…”

Section: Resultsmentioning

confidence: 99%

Silver‐Catalyzed Hydroamination: Synthesis of N‐Bridgehead Pyrroles, Incorporating a Protection‐Deprotection Strategy for Preparation of Cyclic Secondary Vinylogous Carbamates

2005

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Silver‐Catalyzed Hydroamination: Synthesis of N‐Bridgehead Pyrroles, Incorporating a Protection‐Deprotection Strategy for Preparation of Cyclic Secondary Vinylogous Carbamates

2005

View full text Add to dashboard Cite

show abstract

“…Treatment of thiobenzophenone (10c) [18] as well as thiodibenzosuberone (10d) [19] with ca. 1.25 equivalents of LDA and subsequent treatment of the initial product with MeI led to the corresponding methylsulfides 11c [20] and 11d, respectively, which were isolated in 52 and 41% yield (Scheme 4).…”

Section: Methodsmentioning

confidence: 99%

“…Thiofluorenone (10g) [18][23] is a prominent representative of aromatic thioketones, known as a superdipolarophilic agent [2]. But the attempted reduction of 10g with LDA failed, and only traces of the desired methylsulfide were detected in the crude mixture by 1 H-NMR spectroscopy.…”

Section: Methodsmentioning

confidence: 99%

Reduction of Thiocarbonyl Compounds with Lithium Diisopropylamide

Gebert

Jasiński

Mlostoń

et al. 2014

Helvetica Chimica Acta

View full text Add to dashboard Cite

Treatment of 4,4-disubstituted 2-phenyl-1,3-thiazole-5(4H)-thiones with lithium diisopropylamide (LDA; LiNiPr2) in THF at -78°yielded the corresponding 1,3-thiazole-5(4H)-thioles in moderate yields. Sequential treatment with LDA and MeI under the same conditions led to the 5-methylsulfanyl derivatives. Similarly, reaction of some cycloalkanethiones as well as diaryl thioketones with LDA and MeI gave cycloalkyl methyl sulfides and diarylmethyl methyl sulfides, respectively. A reaction mechanism via H transfer from LDA to the thiocarbonyl C-atom via a six-membered transition state is proposed for this unprecedented reduction of the C¼S bond.

show abstract

“…The present work extended to investigate the behaviour of 6,8-dichloro-2-methyl-4H-chromen-4-one (2) towards nitrogen nucleophiles namely, hydrazine hydrate, phenyl hydrazine, hydroxyl amine hydrochloride and ammonium acetate. Thus hydrazinolysis of the chromone derivative 2 with hydrazines namely hydrazine hydrate, phenyl hydrazine in boiling pyridine underwent cleavage of the pyran ring and afforded the corresponding pyrazoles (18a,b), respectively [22,24,40].…”

Section: Synthesismentioning

confidence: 99%

Synthesis, structure characterization and biological evaluation of new 6,8-dichloro-2-methyl-4H-chromen-4-one derivatives

Salem

Marzouk

Ali³

et al. 2012

Eur. J. Chem.

View full text Add to dashboard Cite

KEYWORDSThe typical active methyl functionality of 6,8-dichloro-2-methyl-4H-chromen-4-one is utilized to obtain 2-styrylchromones, pyruvate ester and phthalide via reactions with aromatic carboxaldehydes, diethyl oxalate and phthalic anhydride respectively. The phthalide provides illustrative example to convert a heterocyclic compound to an aliphatic one via the effect of alcoholic sodium methoxide. Bromination and cycloaddition reactions of 2-styrylchromones afford vicinal dibromide and adducts respectively. This work presents to the art a typical example of heterocyclic systems transformations through the conversion of the starting chromone to coumarin under the influence of thionyl chloride followed by aqueous potassium hydroxide. Some heterocyclic systems like pyrazole, isoxazol and quinolinone are obtained from the target chromone by treatment with hydrazines, hydroxylamine hydrochloride and ammonium acetate respectively. Thiation of starting chromone interestingly affords a dithiated product instead of the expected monothiated one. Antibacterial and antifungal activities of some synthesized compounds have been screened.

show abstract

Microwave-Accelerated Solvent-Free Synthesis of Thioketones, Thiolactones, Thioamides, Thionoesters, and Thioflavonoids

Cited by 133 publications

References 38 publications

Silver‐Catalyzed Hydroamination: Synthesis of N‐Bridgehead Pyrroles, Incorporating a Protection‐Deprotection Strategy for Preparation of Cyclic Secondary Vinylogous Carbamates

Silver‐Catalyzed Hydroamination: Synthesis of N‐Bridgehead Pyrroles, Incorporating a Protection‐Deprotection Strategy for Preparation of Cyclic Secondary Vinylogous Carbamates

Reduction of Thiocarbonyl Compounds with Lithium Diisopropylamide

Synthesis, structure characterization and biological evaluation of new 6,8-dichloro-2-methyl-4H-chromen-4-one derivatives

Contact Info

Product

Resources

About