A practical and efficient H/D exchange method for selective deuteration of terminalalkynes was disclosed. The reaction was simply performed with CF3COOAg as catalyst at room temperature, affording products with high level of deuterium incorporation. The excellent site-selectivity and promising functional group tolerance of this protocol enabled deuteration of pharmaceuticals and nature product derivatives
Copper catalyzed hydrodefluorination of propargylic gem-difluorides with “triple bonds migration”
作者:Ting Wang、Zhirong Li、Jiayi Hu、Tao Wu
DOI:10.1016/j.tet.2022.132897
日期:2022.8
A copper catalyzed hydrodefluorination of propargylic gem-difluorides was reported, in which two C–F bonds was reductive converted to C–H bonds and a new alkyne product was afforded with the triple bond migrating one methylene. Mechanistic studies show that the products are achieved by stepwise C–F bond reductive hydrogenation, and an allenyl monofluoride is proposed to be one of the active intermediates
Copper-Catalyzed Regio- and Stereoselective Three-Component Coupling of Allenyl Ethers with <i>gem</i>-Dichlorocyclobutenones and B<sub>2</sub>pin<sub>2</sub>
and stereoselective difunctionalization of allenes with allenyl ethers, bis(pinacolato)diboron, and gem-dichlorocyclobutenones as electrophiles was reported, yielding a variety of highly functionalized cyclobutenone products tethering with an alkenylborate fragment. The polysubstituted cyclobutenone products also underwent diverse transformations.
Access to Chiral <i>O</i>,<i>O</i>‐Acetals Enabled by Palladium‐Catalyzed Asymmetric Addition of Oximes to Alkoxyallenes
作者:Zhuo‐Wei Xu、Shaozhong Wang
DOI:10.1002/chem.202301883
日期:2023.11.21
A palladium-catalyzed chemo-, regio- and stereoselective coupling of oximes and alkoxy allenes enables the access to enantiomerically pure O,O-acetals, in which the hydrogen bonding interaction between the amide group of the diphosphine ligand and the alkoxy allene is decisive for the high enantioselectivity.
钯催化的肟和烷氧基丙二烯的化学、区域和立体选择性偶联能够获得对映体纯的O , O -缩醛,其中二膦配体的酰胺基团和烷氧基丙二烯之间的氢键相互作用对于高对映选择性。
Rapid and General Access to α-Haloketones Using Quaternary Ammonium Salts as Halogen Sources
A general, rapid, and scalable method for the preparation of α-halogenatedketones using N-alkenoxypyridinium salts as substrates and quaternary ammonium salts as halogen sources was developed, featuring mild reaction conditions, excellent functional group tolerance, short reaction times, and a wide substrate scope.