- Cross-Dehydrogenative Coupling of Tetrahydroisoquinolines and 2-Fluoro-1,3-benzodithiole-1,1,3,3-tetraoxide: A New Synthetic Approach to α-Monofluoromethyl Tertiary Amines
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A cross dehydrogenative coupling reaction of tetrahydroisoquinolines with 2-fluoro-1,3-benzodithiole-1,1,3,3-tetraoxide had been developed. CuBr/TBHP was identified as the best catalyst and oxidant. A variety of coupling products were obtained with good t
- Chen, Yuan,Huang, Bao-qin,Yan, Ming,Zhang, Xue-jing
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- Chloroperoxidase-catalyzed asymmetric synthesis of a series of aromatic cyclic sulfoxides
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The chloroperoxidase (CPO) catalyzed oxidation of a series of rigid aromatic sulfides of well-defined geometry has been studied by the use of enantioselective gas chromatography for the determination of product composition and sulfoxide enantiomeric excess. The almost planar 1-thiaindane was found to be an excellent substrate, giving a quantitative yield of the (-)-(R)-1-oxide in 99% e.e. The sterically more demanding next higher homolog with a six-membered heterocyclic ring, 1-thiatetrahydronaphthalene (1-thiochroman), also gave a sulfoxide in high e.e. (≥ 96%) but in a much lower yield, indicating a preserved stereorecognition ability but a lower turnover rate. A carbonyl group in the 4-position (1-thiochroman-4-one) had no further effect on the CPO-mediated sulfoxidation. Enantio-selectivity was lost for the symmetric disulfide, 1,3-benzodithiol, indicating an equal accessibility of the Fe=O complex towards both sulfur atoms and an active site centred above the heme-iron atom. In all cases with pronounced enantioselectivity the reaction gave the (R)-sulfoxide as observed previously with alkyl aryl sulfides. A change of oxygen source from hydrogen peroxide to t-butyl hydroperoxide and a longer reaction time gave a higher chemical but a lower optical yield, most likely due to an increased competition by the uncatalyzed oxidation reaction in this case.
- Allenmark, Stig G.,Andersson, Malin A.
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- 2-FLUORO-1,3-BENZODITHIOL 1,1,3,3-TETRAOXIDE DERIVATIVE, PRODUCTION METHOD THEREOF, AND PRODUCTION METHOD OF MONOFLUOROMETHYL GROUP-CONTAINING COMPOUND USING THE SAME
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A 2-fluoro-1,3-benzodithiol 1,1,3,3-tetraoxide derivative as a monofluoromethyl group introduction agent that is effective as an intermediate in pharmaceutical and agrochemical synthesis, a production method thereof, and a production method of a monofluoromethyl group-containing compound using this 2-fluoro-1,3-benzodithiol 1,1,3,3-tetraoxide derivative are provided. The 2-fluoro-1,3-benzodithiol 1,1,3,3-tetraoxide derivative represented by the following general formula (1) (wherein R1, R2, R3, and R4 each independently represent a hydrogen atom, a straight-chain or branched alkyl group having 1 to 4 carbon atoms, a straight-chain or branched alkyloxy group having 1 to 4 carbon atoms, a halogen atom, a nitro group, or a cyano group), the production method thereof, and various monofluoromethyl group-containing compounds are manufactured using this 2-fluoro-1,3-benzodithiol 1,1,3,3-tetraoxide derivative as a monofluoromethylating agent.
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- 1,3-Benzodithiole-1,1,3,3-tetraoxide (BDT) as a versatile methylation reagent in catalytic enantioselective Michael addition reaction with enals
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A protocol of an organocatalytic highly enantioselective conjugate addition of nucleophilic BDT to enals has been developed and the versatile Michael adducts serve as useful building blocks for a variety of organic transformations.
- Zhang, Shilei,Li, Jian,Zhao, Sihan,Wang, Wei
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supporting information; experimental part
p. 1766 - 1769
(2010/05/19)
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- 1,3-BENZODITHIOLE TETRAOXIDE AS A CH2(2-) SYNTHON
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1,3-Benzodithiole tetraoxide (BDT) 4 is more reactive in alkylation reactions than the commonly used bis(benzenesulfonyl)methane (1).This is demonstrated notably in dialkylations with sterically demanding alkyl halides.Besides its ready access and larger
- Kuendig, E. Peter,Cunningham, Allan F.
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p. 6855 - 6860
(2007/10/02)
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- A SIMPLE SYNTHESIS AND SOME CHEMICAL PROPERTIES OF BENZO-1,4-DITHIAFULVENES
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The synthesis of benzo-1,4-dithiafulvenes by a simple treatment of 2-substituted 1,3-benzodithiolium tetrafluoroborates - obtained starting from carboxylic acids or acyl chlorides and tetrafluoroboric acid/ ether complex - with acetonitrile water is reported.The reaction is very fast and affords the products in high over-all yields and under mild conditions.The reactions of benzo-1,4-dithiafulvenes with reducing agents (zinc/trifluoroacetic acid and acetonitrile, zinc/deuterated trifluoroacetic acid and acetonitrile, Raney nickel) and with oxidizing agents (hydrogen peroxide/ acetic acid, sodium hypochlorite, chlorine gas/water) are also reported.These reactions show the interesting synthetic potential of benzo-1,4-dithiafulvenes.
- Barbero, Margherita,Cadamuro, Silvano,Ceruti, Maurizio,Degani, Iacapo,Fochi, Rita,Regondi, Valeria
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p. 227 - 236
(2007/10/02)
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