72777-78-7Relevant academic research and scientific papers
A facile synthesis of vinyl and allylic 2,2,2-trifluoroethyl phosphonates
Kiddle, James J.,Davis, Ashley A.,Rosen, Jennifer J.
, p. 681 - 684 (1999)
Condensation of several representative aldehydes with the anion derived from tetrakis(2,2,2-trifluoroethyl) methylenediphosphonate, a new Wadsworth-Emmons reagent, afforded (Z)-vinyl phosphonates in good yields. The latter, when treated with a catalytic amount of potassium tert-butoxide in DMSO isomerized to the corresponding (E)-allylic phosphonates, which produce E,Z-dienes when reacted with a second aldehyde.
Unsupported Nanoporous Gold Catalyst for Chemoselective Hydrogenation Reactions under Low Pressure: Effect of Residual Silver on the Reaction
Takale, Balaram S.,Feng, Xiujuan,Lu, Ye,Bao, Ming,Jin, Tienan,Minato, Taketoshi,Yamamoto, Yoshinori
supporting information, p. 10356 - 10364 (2016/08/31)
For the first time, H-H dissociation on an unsupported nanoporous gold (AuNPore) surface is reported for chemoselective hydrogenation of C=C, C=C, C=N, and C=O bonds under mild conditions (8 atm H2 pressure, 90 °C). Silver doping in AuNPore, which was inevitable for its preparation through a process of dealloying of Au-Ag alloy, exhibited a remarkable difference in catalytic activity between two catalysts, Au>99Ag1NPore and Au90Ag10NPore.The former was more active and the latter less active in H2 hydrogenation, while the reverse tendency was observed for O2 oxidation. This marked contrast between H2 reduction and O2 oxidation is discussed. Further, Au>99Ag1NPore showed a high chemoselectivity toward reduction of terminal alkynes in the presence of internal alkynes which was not achieved using supported gold nanoparticle catalysts and other previously known methods. Reductive amination, which has great significance in synthesis of amines due to its atom-economical nature, was also realized using Au>99Ag1NPore, and the Au>99Ag1NPore/H2 system showed a preference for the reduction of aldehydes in the presence of imines. In addition to this high chemoselectivity, easy recovery and high reusability of AuNPore make it a promising heterogeneous catalyst for hydrogenation reactions.
Regio- and stereoselective hydrosilylation of 1,3-enynes catalyzed by palladium
Zhou, Hui,Moberg, Christina
, p. 1444 - 1447 (2013/06/27)
In the presence of Pd(0) and a phosphine, hydrosilylation of 1,3-enynes with Me2SiHCl proceeds to yield dienylsilanes with the silicon function added to the internal alkyne carbon atom and with (E)-configuration of newly formed olefinic bond. The silanols isolated after hydrolysis of the primarily obtained products serve as precursors to conjugated dienes with different substitution patterns.
Diastereoselective liquid assisted grinding: 'Cracking' functional resins to advance chromatography-free synthesis
Shearouse, William C.,MacK, James
, p. 2771 - 2775,5 (2020/09/14)
As regulations that restrict the use of organic solvents become more stringent, ball milling remains an attractive substitute for traditional organic synthesis. However, the mechanochemistry community does not have a purification pathway to complement the solvent-free, ball milling process. Functional resins have proven to be powerful synthetic tools that simplify purification, but traditional handling of these resins restricts their utility, as hazardous organic solvents are needed to swell the resin. Ball milling the functional resin exposes the functional groups as a function of surface area. This report details the use of ball milling and functional resins to perform an environmentally attractive version of the Wittig reaction.
Synthesis of stilbenes promoted by the mixture of zinc and iron powder
Zhanga, Zhiying,Xieb, Yuanyuan,Yua, Xiaochun
experimental part, p. 140 - 142 (2009/10/15)
Stilbenes have been synthesised by a one-pot reaction of aldehydes with benzyl bromide. The reaction was promoted by both triphenylphosphine and the mixture of zinc and iron together in sealed tube. The yields ranged from moderate to excellent.
Zwitterionic phosphonium sulfonates as easily phase-separable ion-tagged wittig reagents
Huo, Congde,He, Xun,Tak, Hang Chan
experimental part, p. 8583 - 8586 (2009/04/04)
(Chemical Equation Presented) Zwitterionic phosphonium sulfonates 3, conveniently derived from TPPMS (1), can be used as Wittig reagents in solution. The excess reagents and byproduct TPPMSO (6) can be easily separated from the product alkenes by simple precipitation with a less polar solvent. The alkenes thus obtained were often sufficiently pure without chromatographic purification. A one-pot protocol for the synthesis of α,β-unsaturated esters has been developed and appears to be convenient.
Lithium hydroxide as base in the Wittig reaction. A simple method for olefin synthesis
Antonioletti,Bonadies,Ciammaichella,Viglianti
, p. 4644 - 4648 (2008/09/20)
A mild and practical procedure for the Wittig olefination, promoted by lithium hydroxide and triphenylbenzyl phosphonium bromide, has been set up for the synthesis of stilbenes and styrenes. The experimental conditions allow aromatic, heteroaromatic, unsaturated and saturated aliphatic aldehydes to give final products in good yields.
Iron-promoted elimination of β-thioalkoxy alcohols. Olefination by coupling of a carbonyl group with a dithioacetal
Huang, Li-Fu,Chen, Chih-Wei,Luh, Tien-Yau
, p. 3663 - 3665 (2008/02/12)
Treatment of propargylic dithiolanes with nBuLi followed by a carbonyl electrophile yields the corresponding propargylic dithioacetals. Upon treatment with 1 equiv of Fe(BCaC)3 and excess MeMgl, elimination of SR and OH moieties from 8 affords the corresponding olefins in satisfactory yield. Benzylic dithioacetals behave similarly. The reaction can be considered an alternative of McMurry coupling of two different carbonyl equivalents.
Synthesis of 4-nitrophenyl sulfones and application in the modified Julia olefination
Mirk, Daniela,Grassot, Jean-Marie,Zhu, Jieping
, p. 1255 - 1259 (2007/10/03)
4-Nitrophenyl (NP) sulfones have been successfully employed in the modified Julia olefination reaction with carbonyl compounds. The olefination reaction proceeds through a sequence of aldol addition, Smiles rearrangement, and elimination. The sulfones are easily prepared in high yields in a two-step sequence starting from inexpensive commercially available para- fluoronitrobenzenes via nucleophilic aromatic substitution by a mercaptane and subsequent oxidation under standard conditions. The modified Julia reaction between NP sulfones and a wide variety of aromatic aldehydes affords the corresponding styrenes, stilbenes and cinnamate derivatives in yields up to 97% and good stereoselectivities. A mechanistic rationale is advanced to explain the observed results. Georg Thieme Verlag Stuttgart.
Palladium-catalyzed elimination reaction of acyclic (E)-allylic acetates: The stereochemistry elucidated by syn-effect
Takenaka, Hiroyuki,Ukaji, Yutaka,Inomata, Katsuhiko
, p. 256 - 257 (2007/10/03)
The stereochemistry of the elimination reaction of acyclic (E)-allylic acetates into the corresponding 1,3-dienes catalyzed by palladium in the presence of a base was investigated. The Z/E ratios of the resulting 1,3-dienes varied with the δ-substituents of the starting allylic acetates. This phenomenon was discussed based on the concept of a syn-effect, which is most primarily rationalized by a σ → π* interaction. Copyright
