Intramolecular Cyclization of N-Propargylic Amides without Transition-Metal Catalysis for Synthesis of Fluoroalkylated Oxazoles: Using Carboxylic Acid Anhydrides as the Fluoroalkyl Source
Organocatalytic Cyclization of COS and Propargylic Derivatives to Value‐Added Heterocyclic Compounds
作者:Hui Zhou、Rui Zhang、Sen Mu、Hui Zhang、Xiao‐Bing Lu
DOI:10.1002/cctc.201900490
日期:2019.12.5
and 1,3‐thiazolidine‐2,4‐diones derivatives in a highly chemo‐ and stereoselective manner. The isotope labeling and stoichiometric experiments suggested the LB‐COS adducts preferentially mediated basic ionic pair mechanism. Furthermore, the practical application of this methodology was highlighted by the highlyefficientsynthesis of rosiglitazone using COS as sulfur source.
Various substituted 1,3‐thiazolidin‐2‐ones can be synthesized by using a tBuOK‐mediated carbonylativecyclization of propargylicamines with elemental sulfur. Benzene‐1,3,5‐triyl triformate (TFBen) serves as a convenient CO surrogate.
Bifunctional Solid Catalyst for Organic Reactions in Water: Simultaneous Anchoring of Acetylacetone Ligands and Amphiphilic Ionic Liquid “Tags” by Using a Dihydropyran Linker
作者:Bingbing Lai、Fuming Mei、Yanlong Gu
DOI:10.1002/asia.201800567
日期:2018.9.4
bifunctional silica‐based solid catalyst that possessed an ionicliquid tail and a metal acetylacetonate moiety was prepared through a mild Lewis‐acid‐catalyzed ring‐opening reaction with a thiol‐functionalized silica. The surfactant‐combined silica‐supported metal acetylacetone catalysts displayed excellent catalytic activity in water for a range of reactions. The solid catalyst was also shown to be recyclable
Synthetic Access to Secondary Propargylamines via a Copper-Catalyzed Oxidative Deamination/Alkynylation Cascade
作者:Huiqiong Li、Huangdi Feng、Jingxian Zhang、Erik V. Van der Eycken、Liliang Huang
DOI:10.1021/acs.joc.9b01431
日期:2019.8.16
cascade reaction of primary amines and alkynes for the synthesis of the corresponding secondary propargylamines is described. This protocol proceeds with a CuBr2/TBHP system through a process of oxidativedeamination of primary amines to imine and alkynylation, featuring a wide scope of substrates with good functional-group tolerance and operational simplicity. Additionally, the use of two different primary
Synthesis of Imidazolidin-2-ones and Imidazol-2-ones via Base-Catalyzed Intramolecular Hydroamidation of Propargylic Ureas under Ambient Conditions
作者:Alessandra Casnati、Antonio Perrone、Paolo P. Mazzeo、Alessia Bacchi、Raffaella Mancuso、Bartolo Gabriele、Raimondo Maggi、Giovanni Maestri、Elena Motti、András Stirling、Nicola Della Ca’
DOI:10.1021/acs.joc.9b00064
日期:2019.3.15
The first organo-catalyzed synthesis of imidazolidin-2-ones and imidazol-2-ones via intramolecular hydroamidation of propargylic ureas is reported. The phosphazene base BEMP turned out to be the most active organo-catalyst compared with guanidine and amidine bases. Excellent chemo- and regioselectivities to five-membered cyclic ureas have been achieved under ambient conditions, with a wide substrate