Synthesis and reactivity of halogeno-difluoromethyl aromatics and heterocycles
作者:Conrad R Burkholder、William R Dolbier、Maurice Médebielle
DOI:10.1016/s0022-1139(01)00378-5
日期:2001.6
HIV, and based on the electrochemical reduction of a series of bromodifluoromethyl compounds, the tetrakis(dimethylamino)ethylene (TDAE) was found to be an effective reductant of the 2-(bromodifluoromethyl)benzoxazole 1 and of the 5-(bromodifluoromethyl)-3-phenyl-1,2,4-oxadiazole 3. A stepwise electron transfer with a difluoromethyl radical as intermediate is assumed to take place in this reaction.
Single electron transfer approaches to the practical synthesis of aromatic and heterocyclic-CF2H derivatives
作者:William R Dolbier、Maurice Médebielle、Samia Ait-Mohand
DOI:10.1016/s0040-4039(01)00873-5
日期:2001.7
Single electron transfer (SET) approaches with organic reductants such as sodium hydroxymethanesulfinate (Rongalite®), sodiumdithionite (regarded as precursors of sulfoxylate radical anion) and tetrakis(dimethylamino)ethylene (TDAE) were employed for the reductive dehalogenation of a series of halogeno-difluoromethylated aromatics and heterocycles, and for the practical synthesis of the corresponding
Difluoromethylation Reactions of Ethyl Pyruvate with the TDAE - A MildApproach to the Synthesis of 3,3-Difluoro-2-hydroxy-2-methyl-4-oxo-butyric Ethyl Esters Derivatives
作者:Maurice Médebielle、Katsuya Kato、William R. Dolbier Jr.
DOI:10.1055/s-2002-33517
日期:——
New 3,3-difluoro-2-hydroxy-2-methyl-4-oxo-butyric ethyl esters derivatives are easily obtained in moderate to good yields from the tetrakis(dimethylamino)ethylene (TDAE) mediated reduction of a series of RCF2X (X = Cl or Br) starting materials in the presence of ethyl pyruvate.
Tetrakis(dimethylamino)ethylene (TDAE) as a useful reductant of some chlorodifluoromethylated ketones. A new approach for the synthesis of α,α-difluoroketone derivatives
作者:Conrad Burkholder、William R. Dolbier、Maurice Me´debielle、Alexandre Ndedi
DOI:10.1016/s0040-4039(98)02028-0
日期:1998.11
Tetrakis(dimethylamino)ethylene (TDAE) was found to be an effective reductant of chlorodifluoromethylated ketones1–3. The generated α,α-difluoroacetyl anion was trapped with several aldehydes4–7, under mild conditions, to give the corresponding 2,2-difluoro-3-hydroxy ketone derivatives8–13, in moderate yields.
Reaction of α-halogen substituted β-ethoxyvinyl trifluoromethyl ketones with 2-aminopyridine: new route to trifluoroacetyl-containing heterocycles
作者:Liliya M Kacharova、Igor I Gerus、Alexey D Kacharov
DOI:10.1016/s0022-1139(02)00190-2
日期:2002.10
The reaction of α-halosubstituted β-ethoxyvinyl trifluoromethyl ketones with 2-aminopyridine gives 3-trifluoroacetyl imidazo[1,2-a]pyridine and 3-halo-1,1,1-trifluoro-4-(2-pyridinylamino)-3-buten-2-ones. The product ratio depends on the nature of the α-halogen atom and the solvent.
α-卤代β-乙氧基乙烯基三氟甲基酮与2-氨基吡啶的反应得到3-三氟乙酰基咪唑并[1,2- a ]吡啶和3-卤代-1,1,1-三氟-4-(2-吡啶基氨基)-3 -丁2个。产物比率取决于α-卤素原子和溶剂的性质。