- Enantioselective Construction of Tertiary Fluoride Stereocenters by Organocatalytic Fluorocyclization
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1,1-Disubstituted styrenes with internal oxygen and nitrogen nucleophiles undergo oxidative fluorocyclization reactions with in situ generated chiral iodine(III)-catalysts. The resulting fluorinated tetrahydrofurans and pyrrolidines contain a tertiary carbon-fluorine stereocenter. Application of a new 1-naphthyllactic acid-based iodine(III)-catalyst allows the control of tertiary carbon-fluorine stereocenters with up to 96% ee. Density functional theory calculations are performed to investigate the details of the mechanism and the factors governing the stereoselectivity of the reaction.
- Biosca, Maria,Eriksson, Lars,Hedberg, Martin,Himo, Fahmi,Lübcke, Marvin,Szabó, Kálmán J.,Wang, Qiang
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supporting information
p. 20048 - 20057
(2020/11/27)
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- From Dichlorocyclopropanes to Furans and Cyclopentadienes via Vinylcarbenes
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Base-induced elimination of dichlorocarbene adducts 2 to 9-alkoxyphenanthrenes 1 leads to furans 6, presumably via cyclopropenes 3 which undergo rearrangement to vinylcarbenes 4 and C-H insertion.By the same sequence, the 9-substituted alkylphenanthrene a
- Mueller, Paul,Pautex, Nicole
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p. 1630 - 1637
(2007/10/02)
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- Fonctionnalisation d'hydrocarbures aromatiques polycycliques. Introduction de fonctions alcool, acide ou amine sur le biphenyle, le fluorene ou le phenanthrene
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With aluminium chloride as a catalyst, 3-methyl-1,3-butanediol, a primary-tertiary diol, yielded Friedel-Crafts primary alcohols with fluorene and biphenyl.The monosubstituted derivatives have been characterized mainly by 13C nmr and polysubstituted products have been obtained with excess diol.With the same substrates and in the same conditions a tertiary-tertiary diol such as 2,5-dimethyl-2,5-hexanediol gave only mono or bicycloalkylated hydrocarbons.The reactions of phtalic anhydride with fluorene, biphenyl and phenanthrene have been studied and the monosubstituted products characterized mainly by 13C nmr by means of a relaxation reagent.Bifunctionalized derivatives were also obtained and identified in the case of fluorene and biphenyl.On the other hand, amino functional groups were introduced on fluorene either by transformation of acid functions or by more direct routes such as reaction with isatoic anhydride or p-toluenesulfonylanthranilic acid.Some results have been used for the functionalization of an industrial residue containing polycyclic aromatic hydrocarbons.
- Guilhemat, Robert,Pereyre, Michel,Petraud, Michel
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p. 334 - 344
(2007/10/02)
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