32064-79-2Relevant articles and documents
Intercepting the Gold-Catalysed Meyer-Schuster Rearrangement by Controlled Protodemetallation: A Regioselective Hydration of Propargylic Alcohols
Pennell, Matthew N.,Kyle, Michael P.,Gibson, Samantha M.,Male, Louise,Turner, Peter G.,Grainger, Richard S.,Sheppard, Tom D.
, p. 1519 - 1525 (2016/05/19)
The regioselective gold-catalysed hydration of propargylic alcohols to β-hydroxy ketones can be achieved by diverting the gold-catalysed Meyer-Schuster rearrangement through the addition of a protic additive with a pKa of 7-9 such as p-nitrophe
Triazole acetyl gold(III) catalyzed Meyer-Schuster rearrangement of propargyl alcohols
Yang, Yongchun,Shen, Yanan,Wang, Xiaoli,Zhang, Yao,Wang, Dawei,Shi, Xiaodong
supporting information, p. 2280 - 2282 (2016/05/10)
A new type triazole acetyl gold(III) was prepared and found to be an effective catalyst in Meyer-Schuster rearrangement of propargyl alcohols. The reactions proceeded well under much milder conditions to afford enones bearing a wide range of functional groups, thereby opening a new avenue for gold(III) catalysis. In addition, TriaAuCl2 catalyst was also effective on promotion of a-haloenones synthesis.
Gold- and silver-catalyzed reactions of propargylic alcohols in the presence of protic additives
Pennell, Matthew N.,Turner, Peter G.,Sheppard, Tom D.
experimental part, p. 4748 - 4758 (2012/05/04)
A wide range of primary, secondary and tertiary propargylic alcohols undergo a Meyer-Schuster rearrangement to give enones at room temperature in the presence of a gold(I) catalyst and small quantities of MeOH or 4-methoxyphenylboronic acid. The syntheses of the enone natural products isoegomaketone and daphenone were achieved using this reaction as the key step. The rearrangement of primary propargylic alcohols can readily be combined in a one-pot procedure with the addition of a nucleophile to the resulting terminal enone, to give β-aryl, β-alkoxy, β-amino or β-sulfido ketones. Propargylic alcohols bearing an adjacent electron-rich aryl group can also undergo silver-catalyzed substitution of the alcohol with oxygen, nitrogen and carbon nucleophiles. This latter reaction was initially observed with a batch of gold catalyst that was probably contaminated with small quantities of silver salt.
Triazole-gold-promoted, effective synthesis of enones from propargylic esters and alcohols: A catalyst offering chemoselectivity, acidity and ligand economy
Wang, Dawei,Zhang, Yanwei,Harris, Alexandria,Gautam, Lekh Nath S.,Chen, Yunfeng,Shi, Xiaodong
supporting information; experimental part, p. 2584 - 2588 (2011/12/01)
The air, moisture and thermally stable 1,2,3-triazole coordinated gold(I) complexes (TA-Au) were revealed as the effective catalysts in promoting propargylic ester rearrangement and sequential allene hydration, giving the enones with excellent yields (up to 97% yields, 0.2% loading). The catalysts could also catalyze the more challenging Meyer-Schuster rearrangement (0.5% loading, up to 98% yields). The reported reaction confirmed TA-Au as a chemoselective catalyst in promoting alkyne activation with high efficiency and improved ligand economy. Copyright
A general procedure for the synthesis of enones via gold-catalyzed Meyer-Schuster rearrangement of propargylic alcohols at room temperature
Pennell, Matthew N.,Unthank, Matthew G.,Turner, Peter,Sheppard, Tom D.
, p. 1479 - 1482 (2011/04/26)
Meyer-Schuster rearrangements of propargylic alcohols take place readily at room temperature in toluene with 1-2 mol % PPh3AuNTf2, in the presence of 0.2 equiv of 4-methoxyphenylboronic acid or 1 equiv of methanol. Good to excellent yields of enones can be obtained from secondary and tertiary alcohols, with high selectivity for the E-alkene in most cases. A one-pot procedure for the conversion of primary propargylic alcohols into β-arylketones was also developed, via Meyer-Schuster rearrangement followed by Pd-catalayzed addition of a boronic acid.(Figure Presented)
The cation exchange resin-promoted coupling of alkynes with aldehydes: one-pot synthesis of α,β-unsaturated ketones
Yadav,Subba Reddy,Vishnumurthy
, p. 4498 - 4500 (2008/09/21)
Alkynes undergo smooth coupling with aldehydes in the presence of Amberlyst-15 at room temperature to produce the corresponding α,β-unsaturated ketones in high yields with E-geometry. The use of an inexpensive, readily available, and recyclable cation exchange resin makes this method quite simple and convenient.
[(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.
Oxidative Synthesis of α,β-Unsaturated Ketone from α-Iodo Ketone Using Peracid
Horiuchi, C. Akira,Ji, Shun-Jun,Matsushita, Masatoshi,Chai, Wen
, p. 202 - 204 (2007/10/03)
Oxidation of α-iodo ketone in CH2Cl2 using m-chloro-perbenzoic acid yields α,β-unsaturated ketone by β-H elimination in good yield. This reaction affords a new and convenient synthetic method for α,β-unsaturated ketone from α-iodo ketone.
NOVEL REDUCTION OF α-BROMO-α,β-UNSATURATED KETONES. SELECTIVE SYNTHESIS OF β,γ-UNSATURATED KETONES
Hirao, Toshikazu,Masunaga, Toshio,Hayashi, Ken-ichiro,Ohshiro, Yoshiki,Agawa, Toshio
, p. 399 - 400 (2007/10/02)
Treatment of α-bromo-α,β-unsaturated ketones or 1,1-dibromo-2-trimethylsiloxycyclopropanes with diethyl phosphite and triethylamine affords β,γ-unsaturated ketones selectively.
