Synthesis of the omega-brominated alpha-trifluoroacetylcycloalkanones and their isoxazole derivatives

Flores, Alex F. C.; Peres, Rodrigo L.; Piovesan, Luciana A.; Flores, Darlene C.; Bonacorso, Hélio G.; Martins, Marcos A. P.

doi:10.1590/s0103-50532006000100012

Cited by 10 publications

(5 citation statements)

References 18 publications

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“…The ω-brominated α-(trifluoroacetyl)cycloalkanones and their isoxazole derivatives were synthesized by Flores et al (Scheme 59). 204 The reaction of a series of the 2-(trifluoroacetyl)-1-methoxy-1-cycloalkenes and 2-(trifluoroacetyl)cycloalkanones with bromine to obtain ω-bromo-α-(trifluoroacetyl)cycloalkanones was reported.…”

Section: Bromination Reactions 31 Bromination With Molecular Brominementioning

confidence: 99%

Use of Bromine and Bromo-Organic Compounds in Organic Synthesis

2016

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Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis.

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Section: Bromination Reactions 31 Bromination With Molecular Brominementioning

confidence: 99%

Use of Bromine and Bromo-Organic Compounds in Organic Synthesis

2016

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“…The unambiguous 1 H and 13 C NMR chemical shift assignments of cycloalka ‐isoxazolines ( 2a , 2b , 2c ), ‐pyrazoles ( 3a , 3b , 3c ), ‐pyrimidinones ( 4a , 4b , 4c ), and ‐pyrazoline ( 5c ), were made with the help of homo‐ and hetero‐ nuclear COSY, HMQC, and HMBC 2D NMR experiments and by comparison with NMR data of the literature [27] and from other 2‐pyrazolines previously synthesized in our laboratory [26, 31(a)].…”

Section: Resultsmentioning

confidence: 99%

“…The preparation of trifluoromethylated heterocyclic compounds from cyclocondensation reactions of β‐alkoxyvinyl trihalomethyl ketones with 1,2 and 1,3 dinucleophilic compounds has been developed by our research group [18–23]. Recently, the synthesis [24] and 17 O NMR spectroscopy of 2‐trifluoroacetyl‐1‐methoxycycloalkenes [25] derived from cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, and cyclododecanone [26] were reported. However, there is no publication in the literature with the objective of carrying out a regiospecific and simultaneous introduction of a trifluoromethyl group and a fused 7‐, 8‐, and 10‐membered cycloalkane ring fused to heterocyclic derivatives starting from b‐alkoxyvinyl trifluoromethyl ketones and hydroxylamine, hydrazines or urea.…”

Section: Introductionmentioning

confidence: 99%

2‐Trifluoroacetyl‐1‐methoxycycloalkenes: A convenient precursor for the synthesis of geminated polymethylene trifluoromethyl substituted heterocycles

Bonacorso

Costa

Cechinel

et al. 2009

Journal of Heterocyclic Chem

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This article describes the methodology that allows the simultaneous introduction of a trifluoromethyl group and a 7-, 8-, and 10-membered cycloalkane ring fused to heterocyclic derivatives. A series of 10 geminated polymethylene trifluoromethyl substituted isoxazolines, pyrazoles, pyrimidinones, and a pyrazolyl-quinoline were obtained in moderate to good yields from the reaction of three 2-trifluoroacetyl-1-methoxycycloalkenes derived from cycloheptanone, cyclooctanone, and cyclododecanone with hydroxylamine hydrochloride, hydrazine hydrochloride, urea, and 7-chloro-4-hydrazinoquinoline.

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“…Thus the treatment of 2-trifluoroacetylcycloalkanones 22 with bromine and pyridine (1 equiv. each) was reported 215 to result in high yields of the o-substitution products 149. However, under similar conditions 2-trifluoroacetylcyclohexanone 22a gave a complex mixture where only the starting 1,3-diketone and trace amounts of compound 149 could be identified by NMR spectroscopy.…”

Section: Miscellaneous Reactionsmentioning

confidence: 99%