56210-74-3Relevant academic research and scientific papers
Facile stereoselective syntheses of aryl substituted α,β-unsaturated esters containing a trifluoromethyl group
Pan, Rui-Qi,Wang, Ping-An,Deng, Min-Zhi
, p. 287 - 290 (2002)
Facile stereoselective synthesis of aryl substituted α,β-unsaturated esters containing a trifluoromethyl group was presented. The Suzuki-type cross-coupling reaction of arylboronic acids with ethyl (Z)-3-iodo-4,4,4-trifluoro-2-butenoate, which was generat
Copper-Photocatalyzed Contra-Thermodynamic Isomerization of Polarized Alkenes
Bouillon, Jean-Philippe,Brégent, Thibaud,Poisson, Thomas
supporting information, p. 7688 - 7693 (2020/10/09)
The contra-thermodynamic isomerization of α- and β-substituted cinnamate derivatives catalyzed by the Cu(OAc)2/rac-BINAP complex under blue light irradiation is reported. The use of an oxazolidinone template, which favored the complexation of the copper catalyst to the substrate, allowed the E → Z isomerization of the catalytically formed chromophore under simple and robust reaction conditions in good to excellent ratios. The mechanism of this process based on the transient formation of a chromophore was also studied.
Blue light-promoted cross-coupling of aryldiazoacetates and diazocarbonyl compounds
Xiao, Tiebo,Mei, Mingjing,He, Yuwei,Zhou, Lei
supporting information, p. 8865 - 8868 (2018/08/17)
A blue light-promoted cross-coupling of two distinct diazo compounds was described. The reaction produces E-configured trisubstituted alkenes in good yields in the absence of catalysts and additives. The reactive free carbene intermediates were generated
Bu 4 N + -Controlled Addition and Olefination with Ethyl 2-(Trimethylsilyl)acetate via Silicon Activation
Das, Manas,Manvar, Atul,Fox, Ian,Roberts, Dilwyn J.,O'Shea, Donal F.
supporting information, p. 2401 - 2406 (2017/09/30)
Catalytic Bu 4 NOAc as silicon activator of ethyl 2-(trimethylsilyl)acetate, in THF, was utilized for the synthesis of β-hydroxy esters, whereas employing catalytic Bu 4 NOTMS gave α,β-unsaturated esters. The established reaction conditions were applicable to a diverse range of aromatic, heteroaromatic, aliphatic aldehydes and ketones. Reactions were achieved at room temperature without taking any of the specialized precautions that are in place for other organometallics. A stepwise olefination pathway via silylated β-hydroxy esters with subsequent elimination to form the α,β-unsaturated ester has been demonstrated. The key to selective product formation lies in use of the weaker acetate activator which suppresses subsequent elimination whereas stronger TMSO - activator (and base) facilitates both addition and elimination steps. The use of tetrabutyl ammonium salts for both acetate and trimethylsilyloxide activators provide enhanced silicon activation when compared to their inorganic cation counterparts.
A Bio-Inspired, Catalytic e → Z Isomerization of Activated Olefins
Metternich, Jan B.,Gilmour, Ryan
, p. 11254 - 11257 (2015/09/21)
Herein, Natures flavin-mediated activation of complex (poly)enes has been translated to a small molecule paradigm culminating in a highly (Z)-selective, catalytic isomerization of activated olefins using (-)-riboflavin (up to 99:1 Z/E). In contrast to the prominent Z → E isomerization of the natural system, it was possible to invert the directionality of the isomerization (E → Z) by simultaneously truncating the retinal scaffold, and introducing a third olefin substituent to augment A1,3-strain upon isomerization. Consequently, conjugation is reduced in the product chromophore leading to a substrate/product combination with discrete photophysical signatures. The operationally simple isomerization protocol has been applied to a variety of enone-derived substrates and showcased in the preparation of the medically relevant 4-substituted coumarin scaffold. A correlation of sensitizer triplet energy (ET) and reaction efficiency, together with the study of additive effects and mechanistic probes, is consistent with a triplet energy transfer mechanism.
Synthesis of β-CF3 ketones from trifluoromethylated allylic alcohols by ruthenium catalyzed isomerization
Bizet, Vincent,Pannecoucke, Xavier,Renaud, Jean-Luc,Cahard, Dominique
supporting information, p. 56 - 61 (2013/11/06)
This work describes the optimization process for the synthesis of β-trifluoromethylated ketones from trifluoromethylated allylic alcohols. This transformation proceeds through a ruthenium catalyzed isomerization under mild conditions with high atom econom
A newly-designed PE-supported arsine for efficient and practical catalytic Wittig olefination
Wang, Peng,Liu, Chun-Rong,Sun, Xiu-Li,Chen, Shuai-Shuai,Li, Jun-Fang,Xie, Zuowei,Tang, Yong
supporting information; experimental part, p. 290 - 292 (2012/01/06)
A newly designed PE-supported arsine has been developed as an excellent catalyst for catalytic Wittig-type olefination. Simple ketones, in particular inactive ketones prove to be suitable substrates for the first time. This reaction provides an easy access to di-, tri-, and tetra-substituted olefins in high yield.
Wittig reaction with ion-supported Ph3P
Shimojuh, Naoya,Imura, Yumi,Moriyama, Katsuhiko,Togo, Hideo
experimental part, p. 951 - 957 (2011/03/18)
Ion-supported Ph3P, 4-(diphenylphosphino)benzyltrimethylammonium bromide A and N-methyl-N-[4-(diphenylphosphino)benzyl]pyrrolidinium bromide B, were used for the Wittig reaction. Ion-supported phosphonium salts A1 and B1, which were prepared from the reactions of ion-supported Ph3P A and B with ethyl bromoacetate, respectively, reacted with aromatic and aliphatic aldehydes in the presence of K2CO3 to give the corresponding α,β-unsaturated ethyl esters in good yields with high purity by simple filtration of the reaction mixture and subsequent removal of the solvent from the filtrate. Similarly, ion-supported phosphonium salts A2 and B2, which were prepared from the reactions of ion-supported Ph3P A and B with p-methylbenzyl bromide, respectively, reacted with aromatic and aliphatic aldehydes in the presence of NaH to provide the corresponding p-methylstyrene derivatives in good yields with high purity by simple filtration of the reaction mixture and the subsequent removal of the solvent from the filtrate. In both reactions, the co-product, ion-supported Ph3PO, could be obtained quantitatively by simple filtration, and was converted into the corresponding ion-supported Ph3P A and B again in high yields using dimethyl sulfate, followed by the reduction with LiAlH4. Recovered and regenerated ion-supported Ph3P A and B could be reused for the same Wittig reaction while maintaining good yields of ethyl (E)-3-(4′-chlorophenyl)-2-propenoate and 1-(4′-chlorophenyl)-2- (4″-methylphenyl)ethene with high purity by simple filtration and removal of the solvent from the filtrate.
Olefination reactions using tetraarylphosphonium (TAP)-supported phosphorus ylides
Lebel, Helene,Davi, Michael,Roy, Marie-Noelle,Zeghida, Walid,Charette, Andre B.
scheme or table, p. 2275 - 2280 (2011/09/15)
Tetraarylphosphonium (TAP)-supported phosphorus ylides were prepared and used in copper-catalyzed olefination reactions with diazo compounds to produce conjugated esters, amides, and phosphonates. The TAP-phosphine oxide can easily be separated from the alkene product, recycled, and reused. Georg Thieme Verlag Stuttgart ? New York.
Construction of optically active CF3-containing quaternary carbon centers via stereospecific SN2′ reaction
Kimura, Mitsuo,Yamazaki, Takashi,Kitazume, Tomoya,Kubota, Toshio
, p. 4651 - 4654 (2007/10/03)
(Chemical Equation Presented) Phosphates from 3-substituted 4,4,4-trifluorobut-2-en-1-ols were found to be effective for construction of CF3-containing quaternary carbon centers by way of Cu(I)-catalyzed Grignard reactions in the presence of ca
