91667-27-5Relevant academic research and scientific papers
Synthesis of (: Z)-β-halo α,β-unsaturated carbonyl systems via the combination of halotrimethylsilane and tetrafluoroboric acid
Da Silva, Vitor A. F.,Da Silva, Gustavo P.,Matsuo, Bianca T.,Ali, Akbar,Davis, Rebecca L.,Zukerman-Schpector, Julio,Corrêa, Arlene G.,Paix?o, Márcio W.
, p. 519 - 526 (2019/01/24)
A convenient and broadly applicable method for the hydrohalogenation of ynones is described, by the combination of halotrimethylsilanes and tetrafluoroboric acid. Practically, one equivalent of HX (Br?nsted acid) and BF3 (Lewis acid) is smoothly generated, which activates the carbonyl compounds. Through this protocol, 42 examples of (Z)-β-halovinyl carbonyl compounds (Cl, Br and I) were obtained, in good yields and high stereoselectivity having 2-MeTHF as a solvent.
Metal-free, Regio-, and Stereo-Controlled Hydrochlorination and Hydrobromination of Ynones and Ynamides
Zeng, Xiaojun,Lu, Zhichao,Liu, Shiwen,Hammond, Gerald B.,Xu, Bo
, p. 13179 - 13187 (2017/12/26)
We developed an atom-economical and metal-free method for the regio- and stereo-selective hydrohalogenation of ynones and ynamides using easy to handle DMPU/HX (X = Br or Cl) reagents. The reaction operates under mild conditions and a range of functional groups is well tolerated. We propose that the hydrohalogenation of ynones gives the anti-addition products via a concerted multimolecular AdE3 mechanism and that the hydrohalogenation of ynamides produces the syn-addition products via a cationic keteniminium intermediate.
Fe(III) halides as effective catalysts in carbon-carbon bond formation: Synthesis of 1,5-dihalo-1,4-dienes, αβ-unsaturated ketones, and cyclic ethers
Miranda, Pedro O.,Diaz, David D.,Padron, Juan I.,Ramirez, Miguel A.,Martin, Victor S.
, p. 57 - 62 (2007/10/03)
(Chemical Equation Presented). Iron(III) halides have proven to be excellent catalysts in the coupling of acetylenes and aldehydes. When terminal acetylenes were used the main products obtained were 1,5-dihalo-1,4-dienes with (E,Z)-stereochemistry contaminated in some cases with (E)-α,β- unsaturated ketones. The former carbonyl derivatives were the sole products isolated when nonterminal aromatic alkynes were used. When homopropargylic alcohols were used, a Prins-type cyclization occurred yielding 2-alkyl-4-halo-5,6-dihydro-2H-pyrans. In addition, anhydrous ferric halides are also shown to be excellent catalysts for the standard Prins cyclization with homoallylic alcohols. Isolation of an intermediate acetal, calculations, and alkyne hydration studies provide substantiation of a proposed mechanism.
Regioselective synthesis of (trifluoromethyl)-β-chloroenones
Alvernhe, Gerard,Bensadat, Abdelkader,Ghobsi, Abdelkader,Laurent, Andre,Laurent, Eliane
, p. 169 - 172 (2007/10/03)
The regioselectivity of the conversion of 1,3-diketones into β-chloroenones can be changed by the appropriate choice of the reagent: reaction with "Vilsmeier's reagent" prepared from POCl3 and dimethylformamide or treatment of the diketone with the oxalyl chloride in the presence of dimethylformamide.
