Heterogeneous gold-catalyzed oxidative cross-coupling of propargylic acetates with arylboronic acids leading to (E)-α-arylenones
作者:Dayi Liu、Quan Nie、Rongli Zhang、Mingzhong Cai
DOI:10.1016/j.tetlet.2018.11.053
日期:2019.1
efficient heterogeneous gold-catalyzed oxidative cross-coupling of propargylic acetates with arylboronic acids has been developed that proceeds smoothly in the presence of Selectfluor and provides a general and powerful tool for the preparation of various valuable α-arylenones with moderate to good yields, excellent E-selectivity, and recyclability of the gold catalyst. The reaction is the first example
“Silver Effect” in Gold(I) Catalysis: An Overlooked Important Factor
作者:Dawei Wang、Rong Cai、Sripadh Sharma、James Jirak、Sravan K. Thummanapelli、Novruz G. Akhmedov、Hui Zhang、Xingbo Liu、Jeffrey L. Petersen、Xiaodong Shi
DOI:10.1021/ja303862z
日期:2012.5.30
Clear experimental evidence from X-ray photoelectron spectroscopy and P-31 NMR spectroscopy has been obtained for the first time to confirm that the combination of Ag+ cation with [L-Au](+) results in the formation of different complexes in solution. Re-evaluation of literature-reported gold-catalyzed reactions revealed a significant difference in the reactivities with and without silver. In extreme cases (more than "rare"), the conventional [L-Au](+) catalysts could not promote the reaction without the presence of silver. This investigation has therefore revealed a long-overlooked "silver effect" in gold catalysis and should lead to revision of the actual mechanism.
AbstractOxidizing gold? A gold(I)/gold(III) catalytic cycle is essential for the first oxidative cross‐coupling reaction in gold catalysis. By using Selectfluor for gold(I) oxidation, this chemistry reveals the synthetic potential of incorporating gold(I)/gold(III) catalytic cycles into contemporary gold chemistry and promises a new area of gold research by merging powerful gold catalysis and oxidative metal‐catalyzed cross‐coupling reactions.magnified image