Ni-Catalyzed β-Alkylation of Cyclopropanol-Derived Homoenolates
作者:L. Reginald Mills、Cuihan Zhou、Emily Fung、Sophie A. L. Rousseaux
DOI:10.1021/acs.orglett.9b03435
日期:2019.11.1
Metalhomoenolates are valuable synthetic intermediates which provide access to β-functionalized ketones. In this report, we disclose a Ni-catalyzed β-alkylation reaction of cyclopropanol-derived homoenolates using redox-active N-hydroxyphthalimide (NHPI) esters as the alkylating reagents. The reaction is compatible with 1°, 2°, and 3° NHPI esters. Mechanistic studies imply radical activation of the
Treatment of tertiary cyclopropyl silyl ethers with diethylaminosulfur trifluoride (DAST) causes ring opening to give allylic fluorides in moderate to high yields.
Reaction of tertiary cyclopropyl silyl ethers with diethylaminosulfur trifluoride: the effects of substituents on the cleavage of the cyclopropane ring
The reaction of tertiary cyclopropanol silyl ethers with diethylaminosulfur trifluoride usually causes ringopening to produce allylic fluorides. However, cyclopropyl silyl ethers bearing a strong electron-donating substituent at C1 or an electron-withdrawing substituent at C2 do not afford allylic fluorides but fluorocyclopropanes. It has also been proved that an electron-donating substituent at C2
DAST-mediated ring-opening of cyclopropyl silyl ethers in nitriles: facile synthesis of allylic amides <i>via</i> a Ritter-type process
作者:Masayuki Kirihara、Riho Nakamura、Kana Nakakura、Kazuki Tujimoto、Mohamed S. H. Salem、Takeyuki Suzuki、Shinobu Takizawa
DOI:10.1039/d2ob00940d
日期:——
A diethylaminosulfur trifluoride (DAST)-mediated ring-opening reaction of cyclopropyl silyl ethers in nitriles produced allylic amides in moderate to good yields (up to 87%). Time course studies using ReactIR and O-isotopic labeling mechanistic studies suggested that the present reaction occurs via a Ritter-type process, leading to the formation of allylic amides.
二乙氨基三氟化硫 (DAST) 介导的环丙基甲硅烷基醚在腈中的开环反应以中等至良好的产率(高达 87%)产生烯丙基酰胺。使用 ReactIR 和 O 同位素标记机理研究的时间过程研究表明,本反应通过Ritter 型过程发生,导致烯丙基酰胺的形成。
A facile cyclopropanol synthesis from β-halo ester with grignard reagent-samarium(II) diiodide couple
Transformation of alpha,beta-halo ester to the cyclopropanols by a coupled reagent of samarium(II) diiodide with Grignard reagent in tetrahydrofuran-hexamethylphosphoric triamide was very successfully under mild conditions.