A Rh(II)- or Ag(I)-Catalyzed Formal C–O Bond Insertion of Cyclic Hemiaminal with Aryl Diazoacetate

Synlett ◽  
2021 ◽  
Author(s):  
Wenhao Hu ◽  
Cong Xu ◽  
Xiangrong Liu ◽  
Xiongda Xie ◽  
Lin Deng ◽  
...  
Keyword(s):  
Reactive Intermediates ◽  
Diazo Compounds ◽  
Synthetic Method ◽  
Amino Ester ◽  
Tertiary Carbon ◽  
Convergent Assembly

AbstractA mild and facile synthetic method via convergent assembly of two reactive intermediates generated in situ has been developed. This method provides an efficient way to construct six- and seven-membered N-heterocycles containing a biaryl linkage. This reaction features a gem-difunctionalization process of diazo compounds with cyclic hemiaminals, delivering α-hydroxyl-β-amino ester derivatives with a tertiary carbon center through a formal C–O bond-insertion transformation.

In situ generation of nitrilium from nitrile ylide and the subsequent Mumm rearrangement: copper-catalyzed synthesis of unsymmetrical diacylglycine esters

2016 ◽  
Vol 14 (45) ◽  
pp. 10723-10732 ◽  
Author(s):  
Jijun Chen ◽  
Ying Shao ◽  
Liang Ma ◽  
Meihua Ma ◽  
Xiaobing Wan
Keyword(s):  
Carboxylic Acid ◽  
Diazo Compounds ◽  
Acid Nitrile ◽  
In Situ Generation

A novel in situ generation of nitrilium from nitrile ylide and the subsequent Mumm rearrangement of carboxylic acid, nitrile, and diazo compounds gave various unsymmetrical diacylglycine esters.

scholarly journals Base-Mediated Generation of Ketenimines from Ynamides: [3+2] Annulation with Azaallyl Anions.

2020 ◽  
Author(s):  
Agathe C. A. D’Hollander ◽  
Eugénie Romero ◽  
Kamsana Vijayakumar ◽  
Camille le Houérou ◽  
Pascal Retailleau ◽  
...  
Keyword(s):  
Dft Calculation ◽  
Reactive Intermediates ◽  
Reaction Conditions ◽  
Stereo Selectivity

Under basic conditions and heat, ynamides can serve as precursor to ketenimines, whose synthetic potential is often hampered by their difficulty of acces. Herein, we report that they can undergo a [3+2] cycloaddition with 2-azaallyl anions, obtained from benzylimines under the same reaction conditions. This reaction between two highly reactive intermediates, both generated in situ from bench stable starting materials, gives access to various nitrogen-rich heterocycles. The reaction usually proceeds with excellent diastereoselectivity, in favor of the cis adduct. Deuteration experiments and DFT calculation helped rationalize the regio and stereo-selectivity of the process as well as the formation of side-products.<br>

Development of sulfide reference materials for in situ platinum group elements and S–Pb isotope analyses by LA-(MC)-ICP-MS

2018 ◽  
Vol 33 (12) ◽  
pp. 2172-2183 ◽  
Author(s):  
Yantong Feng ◽  
Wen Zhang ◽  
Zhaochu Hu ◽  
Yongsheng Liu ◽  
Kang Chen ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Reference Materials ◽  
Platinum Group Elements ◽  
Pb Isotopes ◽  
Synthetic Method ◽  
Pb Isotope ◽  
Icp Ms ◽  
Platinum Group ◽  
Isotope Analyses

A new synthetic method has been used to prepare sulfide reference materials for the in situ analysis of PGEs and S–Pb isotopes. The results indicate that the hydrothermal synthesis of the nanoparticles can serve as a potentially effective approach for the preparation of microanalysis reference materials.

Smart injectable biogels based on hyaluronic acid bioconjugates finely substituted with poly(β-amino ester urethane) for cancer therapy

2019 ◽  
Vol 7 (12) ◽  
pp. 5424-5437 ◽  
Author(s):  
Thavasyappan Thambi ◽  
V. H. Giang Phan ◽  
Seong Han Kim ◽  
Thai Minh Duy Le ◽  
Huu Thuy Trang Duong ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Cancer Therapy ◽  
Chemotherapeutic Drugs ◽  
Amino Ester

In situ-forming injectable biogels (IBGs) have been developed for the programmed delivery of potent chemotherapeutic drugs.

Sodium Selenosulfate from Sodium Sulfite and Selenium Powder: An Odorless Selenylating Reagent for Alkyl Halides to Produce Dialkyl Diselenide Catalysts

Synlett ◽  
2019 ◽  
Vol 30 (14) ◽  
pp. 1698-1702
Author(s):  
Yonghong Liu ◽  
Hai Ling ◽  
Chao Chen ◽  
Qing Xu ◽  
Lei Yu ◽  
...  
Keyword(s):  
Selective Oxidation ◽  
Carbonyl Compounds ◽  
Sodium Sulfite ◽  
Alkyl Halides ◽  
Production Costs ◽  
Synthetic Method ◽  
Practical Applications ◽  
Sodium Selenosulfate ◽  
Villiger Oxidation

Na2SeSO3, which can be generated in situ by the reaction of Na2SO3 with Se power, was found to be an odorless reagent for the selenenylation of alkyl halides to produce dialkyl diselenides. These products have been recently shown to be good catalysts for the Baeyer–Villiger oxidation of carbonyl compounds, for the selective oxidation of alkenes, or for the oxidative deoximation of oximes. By using aqueous EtOH as the solvent and avoiding the generation of a malodourous selenol intermediate, the selenylation reaction with Na2SeSO3 is much more environmentally friendly than conventional methods. Owing to the cheap and abundant starting materials and selenium reagents, our novel synthetic method reduces the production costs of dialkyl diselenides as organoselenium catalysts, thereby advancing practical applications of organoselenium-catalysis technologies.

Construction of trifluoromethylated quaternary stereocenters via p-quinone methides

2020 ◽  
Vol 56 (20) ◽  
pp. 3031-3034 ◽  
Author(s):  
Kyu Terashima ◽  
Tomoko Kawasaki-Takasuka ◽  
Tomohiro Agou ◽  
Toshio Kubota ◽  
Takashi Yamazaki
Keyword(s):  
Synthetic Method ◽  
Quinone Methides ◽  
Quaternary Centers ◽  
Quaternary Stereocenters

Development of a new synthetic method for the construction of quaternary centers with a CF3 group was realized by way of 1,6-addition of various nucleophiles to highly reactive δ-trifluoromethylated p-quinone methides generated in situ.

Aziridinyl imines in organic synthesis: Development of tandem reaction strategies and application to total synthesis of natural products

2013 ◽  
Vol 85 (4) ◽  
pp. 741-753 ◽  
Author(s):  
Hee-Yoon Lee ◽  
Seog-Beom Song ◽  
Taek Kang ◽  
Yoon Jung Kim ◽  
Su Jeong Geum
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Organic Synthesis ◽  
Reactive Intermediates ◽  
Diazo Compounds ◽  
Tandem Reaction ◽  
Cycloaddition Reactions ◽  
Free Radical Reactions ◽  
Sulfur Ylide ◽  
Epoxide Formation

Aziridinyl imines are well-known carbene equivalents because they are precursors of diazo compounds from which reactive intermediates can be produced. These carbene equivalents can be utilized as zwitterionic species, diradicals, or 4π system for cycloaddition reactions. Thus, the intermediates derived from aziridinyl imines have been used in the sulfur-ylide-mediated epoxide formation, tandem free-radical reactions, or cyclopropanation reaction via carbene intermediates to form trimethylenemethane (TMM) diyls, which undergo [2 + 3] cycloaddition reactions to form cyclopentanoids. Diazo compounds generated from aziridinyl imines also react with allenes to form TMM diyls. This reaction was utilized in tandem cycloaddition reactions of linear substrates to form polyquinanes. These tandem reaction strategies were successfully applied to the total synthesis of various cyclopentanoid natural products.

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