Catalytic Use of Low-Valent Cationic Gallium(I) Complexes as π-Acids
作者:Zhilong Li、Guillaume Thiery、Martin R. Lichtenthaler、Régis Guillot、Ingo Krossing、Vincent Gandon、Christophe Bour
DOI:10.1002/adsc.201701081
日期:2018.2.1
and gallium dichloride (i. e. [Ga(I)]+[GaCl4]−) proved to be efficient catalysts for cycloisomerizations, Friedel-Crafts reactions, transfer hydrogenations, and reductive hydroarylations. Their activity is compared to more common Ga(III) complexes. This study shows that even the readily available and yet overlooked gallium dichloride salt can be a more active π-Lewis acid catalyst than gallium trichloride
(Pentamethylcyclopentadienyl)Iridium Dichloride Dimer {[IrCp*Cl2]2}: A Novel Efficient Catalyst for the Cycloisomerizations of Homopropargylic Diols and N-Tethered Enynes
iridium dichloride dimer [IrCp*Cl2]2}-catalyzed hydroalkoxylation of bis-homopropargylicalcohols provides an efficient access to dioxabicyclo[2.2.1]ketals. The cycloisomerizations proceed under mild conditions, with low catalytic loadings and short reaction times. This new protocol involving an Ir(III) catalyst also promoted the cycloisomerization of nitrogen-tethered 1,6-enynes to give azabicyclo[4
Exploring the Versatility of 7‐Alkynylcycloheptatriene Scaffolds Under π‐Acid Catalysis
作者:Marie Vayer、Christophe Bour、Vincent Gandon
DOI:10.1002/ejoc.202000623
日期:2020.9.7
The reactivity of 7‐alkynycycloheptatrienes tethered to an aryl group under π‐acid catalysis has been studied. A variety of useful cyclic products were synthesized via Au(I)‐catalyzed skeletal reorganization, Cu(II)‐catalyzed hydroarylation, or Brønsted acid‐catalyzed tandem hydroarylation/Friedel‐Craftsreaction. We also report a rare type of skeletal reorganization involving the 1,3‐acetonide tether
A new method has been developed for the preparation of 3-bromo-1-phenylallenes from 7-alkynylcycloheptatrienes and N-bromosuccinimide. Trisubstituted bromoallenes were obtained at room temperature in moderate to excellent yields. Functionalization of the carbon–bromine bond via Pd- or Cu-catalyzed cross-coupling reactions easily provided substituted allenes.
Synthesis of fluoranthenes by hydroarylation of alkynes catalyzed by gold(I) or gallium trichloride
作者:Sergio Pascual、Christophe Bour、Paula de Mendoza、Antonio M Echavarren
DOI:10.3762/bjoc.7.178
日期:——
Electrophilic gold(I) catalyst 6 competes with GaCl(3) as the catalyst of choice in the synthesis of fluoranthenes by intramolecularhydroarylation of alkynes. The potential of this catalyst for the preparation of polyarenes is illustrated by a synthesis of two functionalized decacyclenes in a one-pot transformation in which three C-C bonds are formed with high efficiency.
亲电金 (I) 催化剂 6 与 GaCl(3) 竞争作为通过炔烃分子内加氢芳基化合成荧蒽的首选催化剂。这种催化剂用于制备聚芳烃的潜力通过在一锅转化中合成两个官能化十环烯来说明,其中三个 CC 键高效地形成。