14045-44-4Relevant academic research and scientific papers
A two-step sequence to ethyl α-fluorocyclopropanecarboxylates through MIRC reaction of ethyl dichloroacetate and highly regioselective fluorination
Zhang, Min,Gong, Yuefa,Wang, Weizhou
, p. 7372 - 7381 (2013)
A two-step sequence to ethyl α-fluorocyclopropanecarboxylates has been developed. Ethyl α-chlorocyclopropanecarboxylates were first obtained through a Michael-initiated ring closure reaction of terminal electron-deficient olefins with ethyl 2,2-dichloroacetate under mild basic conditions. Subsequent smooth conversion into the corresponding monofluorinated analogues in good yields was through a halogen exchange reaction with potassium bifluoride. Further investigation clearly demonstrated that potassium bifluoride in this reaction system played a dual role of base and nucleophilic reagent. This is the first successful example reported hitherto for producing ethyl α-fluorocyclopropanecarboxylate directly through fluorination of its chlorinated analogue with alkali bifluoride. A convenient two-step method to prepare ethyl α-fluorocyclopropanecarboxylates has been developed. Ethyl α-chlorocycloproanecarboxylates were obtained through Michael-initiated ring closure reactions under mild reaction conditions in good yields before being smoothly converted into the corresponding monofluorinated analogues through halogen exchange reactions with potassium bifluoride in good yields. The reaction mechanism was also investigated. Copyright
An unexpected highly stereoselective double aza-Baylis - Hillman reaction of sulfonated imines with phenyl vinyl ketone
Shi, Min,Xu, Yong-Mei
, p. 4784 - 4790 (2003)
The aza-Baylis - Hillman reaction of N-sulfonated imine with phenyl vinyl ketone gave the double aza-Baylis - Hillman adduct in good yields with excellent stereoselectivities in the presence of Lewis base 1,4-diazabicyclo[2.2.2] octane.
Baylis-Hillman reaction of arylaldehydes with phenyl vinyl ketone, phenyl acrylate, and phenyl thioacrylate
Shi, Min,Li, Chao-Qun,Jiang, Jian-Kang
, p. 1051 - 1057 (2002)
In the Baylis-Hillman reaction of aryl aldehydes with phenyl vinyl ketone, we found that the diadduct 4 was exclusively formed, and that the yield of 4 can reach 80% with increasing amounts of phenyl vinyl ketone. But, for phenyl acrylate and phenyl thioa
Different reaction patterns in the Baylis-Hillman reaction of aryl aldehydes with phenyl vinyl ketone, phenyl acrylate and phenyl thioacrylate
Shi, Min,Li, Chao-Qun,Jiang, Jian-Kang
, p. 721 - 733 (2002)
In the Baylis-Hillman reaction of aryl aldehydes with phenyl vinyl ketone we have observed exclusive formation of diadducts 4, and that the yields of diadduct can reach 80% with increasing amounts of phenyl vinyl ketone. On the other hand, for phenyl acrylate and phenyl thioacrylate, only the normal Baylis-Hillman adduct was obtained. The effects of substituents were also examined and a plausible reaction mechanism is proposed for the formation of compounds 4.
Additive-Free Isomerization of Allylic Alcohols to Ketones with a Cobalt PNP Pincer Catalyst
Spiegelberg, Brian,Dell'Acqua, Andrea,Xia, Tian,Spannenberg, Anke,Tin, Sergey,Hinze, Sandra,de Vries, Johannes G.
supporting information, p. 7820 - 7825 (2019/05/22)
Catalytic isomerization of allylic alcohols in ethanol as a green solvent was achieved by using air and moisture stable cobalt (II) complexes in the absence of any additives. Under mild conditions, the cobalt PNP pincer complex substituted with phenyl groups on the phosphorus atoms appeared to be the most active. High rates were obtained at 120 °C, even though the addition of one equivalent of base increases the speed of the reaction drastically. Although some evidence was obtained supporting a dehydrogenation–hydrogenation mechanism, it was proven that this is not the major mechanism. Instead, the cobalt hydride complex formed by dehydrogenation of ethanol is capable of double-bond isomerization through alkene insertion–elimination.
Bi(OTf)3 catalyzed synthesis of acyclic β-sulfanyl ketones via a tandem Meyer-Schuster rearrangement/conjugate addition reaction
Wang, Yuan,Yin, Yan,Zhang, Qinglin,Pan, Wanyong,Guo, Huifeng,Pei, Keke
, p. 2030 - 2034 (2019/07/03)
A new strategy to prepare acyclic β-carbonyl thioethers from propargyl alcohols and sulfur nucleophiles is reported. The investigation of the reaction substrates scope indicated that primary 3-aryl propargyl alcohols and thiols underwent the transformation smoothly. The reaction probably proceeded a Bi(OTf)3-catalyzed tandem Meyer-Schuster rearrangement of 3-aryl propargyl alcohol, followed by a thiol Michael conjugate addition of thiols to in situ generated α, β-unsaturated ketones. The method was 100% atom economic, high-yielding, and easy to handle, making it a valuable method for the construction of β-carbonyl sulfides.
Metal- and Acid-Free Methyl Triflate Catalyzed Meyer-Schuster Rearrangement
Yang, Lu,Zeng, Qingle
, p. 3149 - 3156 (2017/07/12)
A novel metal- and acid-free preparation of synthetically useful α,β-unsaturated carbonyl compounds from propargyl alcohols has been realized. This Meyer-Schuster rearrangement process is effectively catalyzed by methyl triflate (20 mol%) to prepare a broad scope of conjugated E -enals and E -enones generally in good to excellent yields (up to 90%). This reaction procedure operates under mild conditions (70 °C), in air, with short reaction times (1 h). Moreover, a carbocation intermediate trapped by the solvent 2,2,2-trifluoroethanol was isolated during this transformation.
Fe(OTf)3-catalyzed tandem Meyer-Schuster rearrangement/intermolecular hydroamination of 3-aryl propargyl alcohols for the synthesis of acyclic β-Aminoketones
Tao, Ruiheng,Yin, Yan,Duan, Yongbin,Sun, Yuxing,Sun, Yue,Cheng, Fengkai,Pan, Jinpeng,Lu, Cheng,Wang, Yuan
, p. 1762 - 1768 (2017/03/08)
Fe(OTf)3-catalyzed synthesis of acyclic β-aminoketones from 3-aryl propargyl alcohols and nitrogen nucleophiles were investigated. Results showed that propargyl alcohols without bulky groups α to the hydroxyl group underwent the transformation smoothly. Sulphonamides exhibited the higher reactivity than amides as the nitrogen nucleophiles and the transformation of acyclic β-aminoketones were finished in shorter reaction time and higher yields. Finally, racemic fluoxetine was efficiently accessed with the present reaction as the first step. This novel synthesis of acyclic β-aminoketones probable proceeded a Fe(OTf)3-catalyzed Meyer-Schuster rearrangement of 3-aryl propargyl alcohols, followed by a intermolecular hydroamination between nitrogen nucleophiles and α, β-unsaturated ketones.
Rhodium(I)-catalyzed arylation of β-chloro ketones and related derivatives through domino dehydrochlorination/conjugate addition
Jiang, Quanbin,Guo, Tenglong,Wang, Qingfu,Wu, Ping,Yu, Zhengkun
supporting information, p. 1874 - 1880 (2013/07/19)
Highly efficient arylations of β-chloro ketones and their ester and amide derivatives were achieved by means of domino dehydrochlorination/Rh(I)- catalyzed conjugate addition. In situ generated vinyl ketones and their analogues were identified as the reaction intermediates. The present synthetic protocol provides a concise route to (chiral) β-aryl ketones, esters, and amides. Copyright
A practical synthesis of morita-baylis-hillman adducts of aryl vinyl ketones catalyzed by a proton donor
Kim, Sung Hwan,Kim, Se Hee,Lim, Cheol Hee,Kim, Jae Nyoung
experimental part, p. 2023 - 2027 (2012/07/28)
An efficient and practical synthesis of MBH adducts of aryl vinyl ketones was developed using DABCO and 4-nitrophenol as a proton donor. Addition of a proton donor and the use of excess amounts (3.0 equiv) of aldehydes were highly beneficial for the yield
