903512-24-3Relevant academic research and scientific papers
The synthesis and structural characterization of furanyl-1,2,3-triazole Gold(I) and its application in synthesis of enones from propargylic esters and alcohols
Yao, Wei,Zhang, Yilin,Xu, Xiaqing,Yang, Yongchun,Zeng, Wei,Wang, Dawei
supporting information, (2019/10/04)
Furanyl-1,2,3-triazole gold(I) was designed, synthesized and characterized by X-ray crystallography, and was found to exhibit high catalytic activity for the synthesis of enones in good to high yields through a propargylic ester rearrangement and subsequent hydration. Notably, excellent E/Z selectivity was observed in these transformations. This catalyst was also effective in catalyzing the rearrangement of propargylic alcohols and hydration of alkynes. Compared to triazole acetyl gold(III) and other gold complexes, the furanyl-1,2,3-triazole gold(I) is able to promote these transformations smoothly at a low temperature with the E isomer of enones as the only product.
Design and Synthesis of Alanine Triazole Ligands and Application in Promotion of Hydration, Allene Synthesis and Borrowing Hydrogen Reactions
Yang, Yongchun,Qin, Anni,Zhao, Keyan,Wang, Dawei,Shi, Xiaodong
supporting information, p. 1433 - 1439 (2016/05/19)
A new type of alanine triazole (ATA) ligand was found to be an efficient partner for the stabilization of gold(III), thus rendering improved stability and high catalytic activities in allene synthesis and hydration reactions through the 3,3′-arrangement of propargyl esters and propargyl alcohols. In addition to Au(I), ATA-gold(III) was also proven to be an effective catalyst in promoting the formation of allenes with high yields. Furthermore, alanine triazole ruthenium has exhibited excellent potential as a means to catalyze borrowing hydrogen of alcohols and amines, ketones and alcohols.
Gold-acetonyl complexes: From side-products to valuable synthons
Gasperini, Danila,Collado, Alba,Goméz-Suárez, Adrián,Cordes, David B.,Slawin, Alexandra M. Z.,Nolan, Steven P.
supporting information, p. 5403 - 5412 (2015/03/30)
A new synthetic strategy was devised leading to the formation of complexes, such as [Au(IPr)(CH2COCH3)]. The approach capitalizes on the formation of a decomposition product observed in the course of the synthesis of [Au(IPr)(Cl)]. A library of gold acetonyl complexes containing the most common N-heterocyclic carbene (NHC) ligands has been synthesized. These acetonyl complexes are good synthons for the preparation of numerous organogold complexes. Moreover, they have proven to be precatalysts in common gold(I)-catalyzed reactions. Organogold: A library of [Au(NHC)(acetonyl)] complexes (NHC=N-heterocyclic carbene) has been easily synthesized. These complexes represent valuable synthetic precursors to a plethora of organogold species, as well as active catalysts for gold(I)-catalyzed reactions (see scheme).
Quantitative kinetic investigation of triazole-gold(i) complex catalyzed [3,3]-rearrangement of propargyl ester
Xi, Yumeng,Wang, Qiaoyi,Su, Yijin,Li, Minyong,Shi, Xiaodong
supporting information, p. 2158 - 2160 (2014/02/14)
The triazole-gold(i) complex catalyzed [3,3]-rearrangement of propargyl ester has been quantitatively investigated through in situ IR. First order dependence of the initial rates on [Au] and [propargyl ester] suggested that the turnover-limiting step is the associative ligand substitution. The activation enthalpy was also determined to be 7.8 kcal mol-1. TA-Au catalysts with different triazole derivatives were also tested, giving a linear free energy relationship with a ρ value of 0.74. The Royal Society of Chemistry.
Influence of a very bulky N- Heterocyclic Carbene in Gold-Mediated Catalysis
Gomez-Suarez, Adrian,Ramon, Ruben S.,Songis, Olivier,Slawin, Alexandra M. Z.,Cazin, Catherine S. J.,Nolan, Steven P.
scheme or table, p. 5463 - 5470 (2011/12/13)
The syntheses of the free carbene IPr* (IPr* = 1,3-bis(2,6-bis(diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene) and related gold complexes [Au(IPr*)Cl] (C1) and [Au(IPr*)(NTf2)] (C2) were achieved in high yields. The % VBur of IPr* for both gold complexes was measured, revealing IPr* as one of the bulkiest NHCs on gold complexes reported to date. In addition, the catalytic activity of C1 and C2 in several reactions, typically catalyzed by AuI complexes, was investigated. Examples include the tandem alkoxylation/lactonization of γ-hydroxy-α,β-acetylenic esters, the [3,3]-rearrangement of propargylic acetates leading to the formation of conjugated enones and substituted indenes, and the rearrangement of allylic acetates. These studies revealed a strong solvent effect on the catalytic activity with 1,2-dichloroethane as the solvent of choice. The screening of C1 and C2 demonstrated only slightly diminished activities in comparison to [Au(NHC)(L)] complexes bearing bulky ligands such as IPr and SIPr.
1,2,3-triazole bound Au(I) (TA-Au) as chemoselective catalysts in promoting asymmetric synthesis of substituted allenes
Wang, Dawei,Gautam, Lekh Nath S.,Bollinger, Cynthia,Harris, Aleksandra,Li, Minyong,Shi, Xiaodong
supporting information; experimental part, p. 2618 - 2621 (2011/07/08)
The triazole-Au (TA-Au) complexes were identified as effective chemoselective catalysts in promoting propargyl ester/ether 3,3-rearrangements. The highly reactive allenes, which could not be isolated by simple cationic gold catalysts, were prepared in exc
[(NHC)AuI]-catalyzed formation of conjugated enones and enals: An experimental and computational study
Marion, Nicolas,Carlqvist, Peter,Gealageas, Ronan,De Fremont, Pierre,Maseras, Feliu,Nolan, Steven P.
, p. 6437 - 6451 (2008/02/13)
The [(NHC)AuI]-catalyzed (NHC = N-heterocyclic carbene) formation of α,β-unsaturated carbonyl compounds (enones and enals) from propargylic acetates is described. The reactions occur at 60°C in 8 h in the presence of an equimolar mixture of [(NHC)AuCl] and AgSbF6 and produce conjugated enones and enals in high yields. Optimization studies revealed that the reaction is sensitive to the solvent, the NHC, and, to a lesser extent, to the silver salt employed, leading to the use of [(ItBu)AuCl]/ AgSbF6 in THF as an efficient catalytic system. This transformation proved to have a broad scope, enabling the stereoselective formation of (E)-enones and -enals with great structural diversity. The effect of substitution at the propargylic and acetylenic positions has been investigated, as well as the effect of aryl substitution on the formation of cinnamyl ketones. The presence or absence of water in the reaction mixture was found to be crucial. From the same phenylpropargyl acetates, anhydrous conditions led to the formation of indene compounds via a tandem [3,3] sigmatropic rearrangement/intramolecular hydroarylation process, whereas simply adding water to the reaction mixture produced enone derivatives cleanly. Several mechanistic hypotheses, including the hydrolysis of an allenol ester intermediate and SN2′ addition of water, were examined to gain an insight into this transformation. Mechanistic investigations and computational studies support [(NHC)AuOH], produced in situ from [(NHC)AuSbF6] and H 2O, instead of cationic [(NHC)AuSbF6] as the catalytically active species. Based on DFT calculations performed at the B3LYP level of theory, a full catalytic cycle featuring an unprecedented transfer of the OH moiety bound to the gold center to the C≡C bond leading to the formation of a gold-allenolate is proposed.
AuI-catalyzed tandem [3,3] rearrangement-intramolecular hydroarylation: Mild and efficient formation of substituted indenes
Marion, Nicolas,Diez-Gonzalez, Silvia,De Fremont, Pierre,Noble, April R.,Nolan, Steven P.
, p. 3647 - 3650 (2008/03/11)
(Chemical Equation Presented) Dignified auration: The rearrangement of phenylpropargyl acetates to substituted indenes is catalyzed by [Au 1(NHC)] complexes (see scheme, NHC = N-heterocyclic carbene) under extremely mild reaction conditions. This chemoselective transformation involves 1,3-migration of the acetate group and is proposed to proceed through an allene intermediate. TMS = trimethylsilyl, TBS = tert-butyldimethylsilyl.
