o-Iodoxybenzoic acid (IBX): a versatile reagent for the synthesis of N-substituted pyrroles mediated by β-cyclodextrin in water
摘要:
o-Iodoxybenzoic acid (IBX), a very mild and efficient hypervalent iodine(V) reagent, aromatizes diversely substituted 1-benzylpyrrolidines and N-substituted L-proline analogues to the corresponding substituted pyrroles in good to excellent yields under mild conditions mediated by beta-cyclodextrin in water at room temperature. To the best of our knowledge, this is the first report on IBX, promoting complete aromatization leading to N-benzylpyrroles from the corresponding saturated five membered heterocyclic derivatives in water medium. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of tertiary amines by direct Brønsted acid catalyzed reductive amination
作者:Mohanad A. Hussein、An H. Dinh、Vien T. Huynh、Thanh Vinh Nguyen
DOI:10.1039/d0cc02955f
日期:——
reductive amination reaction of carbonyl compounds. Despite developments of numerous new reductive amination methods in the past few decades, this reaction generally requires non-atom-economic processes with harsh conditions and toxic transition-metal catalysts. Herein, we report simple yet practical protocols using triflic acid as a catalyst to efficiently promote the direct reductive amination reactions
hydrogen evolution ortho-aminoalkylation of phenolic derivatives with cyclic amines as the coupling agents. The developed cross-coupling reaction offers a practical platform for direct access to a variety of functionalized phenols with the features of good substrate and functional group compatibility, readily available catalyst system and feedstocks, no need for additional sacrificial oxidants, and high
Visible‐Light‐Mediated C(sp
<sup>3</sup>
)–H Thiocarbonylation for Thiolactam Preparation with Potassium Sulfide
作者:Wei Tan、Cuihong Wang、Xuefeng Jiang
DOI:10.1002/cjoc.201900360
日期:2019.12
thiolactam preparation with potassium sulfide via visible‐light‐mediated C(sp3)–H thiocarbonylation, in which polysulfide dianions and radical anions generated from potassium sulfide were the key active species. A variety of thiolactams were straightforward established under mild conditions. Moreover, it was successfully applied to structural modification of tetrahydroberberine.
Reductive Amination of Aldehydes Using Aminoboranes as Iminium Ion Generators
作者:Michinori Suginome、Yusuke Tanaka、Tomoaki Hasui
DOI:10.1055/s-2006-939070
日期:——
2-Dialkylamino-4H-1,3,2-benzodioxaborins, salicyl alcohol derived aminoboranes, serve as efficient and mild iminium ion generators in the reductive amination of aldehydes with NaBH4. Using a diisopropylamino derivative, a variety of amines including secondary and primary amines, and ammonia can participate to the reductive amination in aprotic organic solvents without the use of acidic promoters.
C–N Coupling of nitrogen nucleophiles with aryl and heteroaryl bromides using aminoarenethiolato–copper(I) (pre-)catalyst
作者:Elena Sperotto、Gerard P.M. van Klink、Johannes G. de Vries、Gerard van Koten
DOI:10.1016/j.tet.2010.03.040
日期:2010.5
pre-catalysts are thermally stable, are soluble in common organic solvents and show good catalytic activities in these N-arylation reactions with catalyst loadings amounting to 2.5 mol %. The targeted C–Ncoupling products were obtained in moderate to good yields (40–97%) for a variety of substrates.