Triethylaluminum- or Triethylborane-Induced Free Radical Reaction of Alkyl Iodides and α,β-Unsaturated Compounds

Liu, Jing Yuan; Jang, Yoeng Jiunn; Lin, Wen Ting; Liu, Ju Tsung; Yao, Ching Fa

doi:10.1021/jo020681b

Cited by 44 publications

(16 citation statements)

References 127 publications

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“…On the other hand, examination of the related synthesis of 3-cyclohexylcyclohexanone from 2-cyclohexenone by two alternative procedures, the photochemical alkylation by using directly cyclohexane 26 and the thermal alkylation with iodocyclohexane 27 shows that the former gives a result similar to the other photochemical synthesis according to equation 2, but the latter, if carried out as reported by using [(PhCOO) 2 , AlCl 3 ] as the activator gets poor marks, mainly due to the dichloromethane used in the work up. An improvement of the environmental impact of this process would be represented by using triethyborane instead of aluminium chloride.…”

Section: Alkylation Reactionsmentioning

confidence: 99%

Assessing photochemistry as a green synthetic method. Carbon–carbon bond forming reactions

et al. 2009

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Section: Alkylation Reactionsmentioning

confidence: 99%

Assessing photochemistry as a green synthetic method. Carbon–carbon bond forming reactions

et al. 2009

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“…We found that the desired cascade process occurred upon photolysis with a simple sunlamp at 0 °C 38. Efforts to discover the optimal promoter for the radical–polar crossover step revealed that Et 3 Al31 was more effective than Et 3 B29 or Et 2 Zn30 (cf. entry 6 vs entries 1 and 3 or entry 7 vs entries 2 and 4).…”

Section: Resultsmentioning

confidence: 99%

Enantioselective Total Synthesis of (−)-Acutumine

Tartakoff

Castle

2009

J. Org. Chem.

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An account of the total synthesis of the tetracyclic alkaloid (−)-acutumine is presented. A firstgeneration approach to the spirocyclic subunit was unsuccessful due to incorrect regioselectivity in a radical cyclization. However, this work spawned a second-generation strategy in which the spirocycle was fashioned via a radical-polar crossover reaction. This process merged an intramolecular radical conjugate addition with an enolate hydroxylation, and created two stereocenters with excellent diastereoselectivity. The reaction was promoted by irradiation with a sunlamp, and a ditin reagent was required for aryl radical formation. These facts suggest that the substrate may function as a sensitizer, thereby facilitating homolytic cleavage of the ditin reagent. The propellane motif of the target was then installed via annulation of a pyrrolidine ring onto the spirocycle. The sequence of reactions used included a phenolic oxidation, an asymmetric ketone allylation mediated by Nakamura's chiral allylzinc reagent, an anionic oxy-Cope rearrangement, a one-pot ozonolysis-reductive amination, and a Lewis acid promoted cyclization of an amine onto an α,β-unsaturated dimethyl ketal. Further studies of the asymmetric ketone allylation demonstrated the ability of the Nakamura reagent to function well in a mismatched situation. A TiCl 4 -catalyzed regioselective methyl enol etherification of a 1,3-diketone completed the synthesis.

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“…Several multi-component domino reactions based on the 'switchable' properties of organozinc compounds have already been proposed. reported to form boron enolates via homolytic substitution at triethylborane [23].…”

Section: Discussionmentioning

confidence: 99%