Passerini reactions for the efficient synthesis of 3,3-disubstituted oxetanes
作者:Benjamin O. Beasley、Guy J. Clarkson、Michael Shipman
DOI:10.1016/j.tetlet.2012.03.065
日期:2012.6
Three-component reactions of oxetan-3-ones with isocyanides and carboxylic acids produce 3,3-disubstitutedoxetanes in good yields. Good levels of diastereocontrol (dr = 4:1) can be achieved in these Passerini reactions when the oxetane nucleus possesses a bulky cyclohexyl substituent at C–2. The (2S∗,3R∗)-stereochemistry of the major diastereomer was confirmed by X-ray crystallography after ester
氧杂环丁烷-3-酮与异氰酸酯和羧酸的三组分反应以良好的产率产生3,3-二取代的氧杂环丁烷。当氧杂环丁烷核在C-2处具有庞大的环己基取代基时,在这些Passerini反应中可以达到良好的非对映控制水平(dr = 4:1)。酯水解后,X射线晶体学证实了主要的非对映异构体的(2 S ∗,3 R ∗)-立体化学,并提出了可能的机制来解释非对映体的选择性。
Gold-Catalyzed One-Step Practical Synthesis of Oxetan-3-ones from Readily Available Propargylic Alcohols
作者:Longwu Ye、Weimin He、Liming Zhang
DOI:10.1021/ja1033952
日期:2010.6.30
A general solution for the synthesis of various oxetan-3-ones is developed. This reaction uses readily available propargylic alcohols as substrates and proceeds without the exclusion of moisture or air ("open flask"). Notably, oxetan-3-one, a highly valuable substrate for drug discovery, can be prepared in one step from propargyl alcohol in a fairly good yield. The facile formation of the strained
On the Regioselectivity of the Nickel-Catalyzed Insertion of Alkynes into the Carbon–Carbon Bond of Oxetan-3-one
作者:Christophe Aïssa、Manuel Barday、Christopher Janot、Daniel Clare、Caitlin Carr-Knox、Bradley Higginson、Kelvin Ho
DOI:10.1055/s-0036-1589052
日期:2017.8
of unsymmetrical alkynes into the carbon–carbonbond of oxetan-3-one in the presence of a nickel catalyst has revealed a strong directing effect of a 2-thienyl substituent. This effect is larger than those of 2-vinylbenzene, trimethylsilyl, aryl, or 3-thienyl groups. The study of the regioselectivity of insertion of unsymmetrical alkynes into the carbon–carbonbond of oxetan-3-one in the presence of
Pictet–Spengler reactions of oxetan-3-ones and related heterocycles
作者:Benjamin O. Beasley、Abimbola Alli-Balogun、Guy J. Clarkson、Michael Shipman
DOI:10.1016/j.tetlet.2013.11.077
日期:2014.1
Pictet–Spengler reactions of oxetan-3-ones and azetidin-3-ones with tryptamine and tryptophan derivatives produce spirocyclic tetrahydro-β-carbolines in good yields. Molecular iodine (5 mol %) is an effective catalyst in most cases and high levels of diastereoselectivity are witnessed using2-substituted oxetan-3-ones.
opening of the spirodiepoxide by a halide nucleophile, and then intramolecular displacement of a halide by an alkoxide. The second method involves allene epoxidation and then thermal rearrangement of the corresponding spirodiepoxide to oxetan-3-one. The two methods are complementary and stereochemically divergent. Computational analysis of the thermal rearrangement is also described.