6050-00-6Relevant academic research and scientific papers
Z-Selective α-Arylation of α,β-Unsaturated Nitriles via [3,3]-Sigmatropic Rearrangement
Chen, Mengyuan,Liang, Yuchen,Dong, Taotao,Liang, Weijian,Liu, Yanping,Zhang, Yage,Huang, Xin,Kong, Lichun,Wang, Zhi-Xiang,Peng, Bo
supporting information, p. 2339 - 2345 (2020/11/30)
The Morita-Baylis–Hillman (MBH) reaction and [3, 3]-sigmatropic rearrangement are two paradigms in organic synthesis. We have merged the two types of reactions to achieve [3,3]-rearrangement of aryl sulfoxides with α,β-unsaturated nitriles. The reaction was achieved by sequentially treating both coupling partners with electrophilic activator (Tf2O) and base, offering an effective approach to prepare synthetically versatile α-aryl α,β-unsaturated nitriles with Z-selectivity through direct α-C-H arylation of unmodified α,β-unsaturated nitriles. The control experiments and DFT calculations support a four-stage reaction sequence, including the assembly of Tf2O activated aryl sulfoxide with α,β-unsaturated nitrile, MBH-like Lewis base addition, [3,3]-rearrangement, and E1cB-elimination. Among these stages, the Lewis base addition is diastereoselective and E1cB-elimination is cis-selective, which could account for the remarkable Z-selectivity of the reaction.
Method for preparing alpha-aryl nitrile and compound
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Paragraph 0120; 0123-0124; 0147-0149, (2021/01/12)
The invention discloses a method for preparing alpha-aryl nitrile, which comprises the following steps: assembling aryl sulfoxide and alpha, beta unsaturated nitrile under the action of an activator to form a rearrangement precursor, rearranging the rearrangement precursor under the action of alkali to obtain a rearrangement intermediate, adding inorganic alkali, and reacting at room temperature to obtain alpha-aryl nitrile. The invention also discloses a product obtained by the preparation method. Compared with the prior art, the method synthesizes alpha-aryl nitrile from aryl sulfoxide and alpha, beta unsaturated nitrile under mild conditions, and has the advantages that 1) the method is mild in reaction condition, good in selectivity, high in yield, easy in product separation, simple tooperate and good in functional group compatibility; 2) the raw materials used in the method are cheap and easily available, so that the defects that the alkalinity is too strong, the reaction condition requirement is strict and the reaction substrate is limited in the traditional method are avoided; and 3) the reaction mechanism is novel, and a new synthetic route is opened up for benzene ring ortho-position functionalization.
Nickel-catalyzed regioselective hydrocyanation of terminal alkynes by assistance of a tosyl group
Arai, Shigeru,Nakazawa, Koichi,Yang, Xiao-fei,Nishida, Atsushi
, p. 2482 - 2485 (2019/03/26)
Nickel-catalyzed regioselective hydrocyanation of terminal alkynes is described. A tosylamide functionality at the propargyl position was the most suitable group for controlling the regiochemistry for C–CN bond formation as well as rate enhancement. A gram-scale synthesis was achieved by minimizing the catalyst loading to 2 mol%. The major HCN adduct could be transformed to the corresponding indoline through construction of a benzylic quaternary carbon under iron catalysis.
Palladium-catalyzed heck-type cross-couplings of unactivated alkyl iodides
McMahon, Caitlin M.,Alexanian, Erik J.
, p. 5974 - 5977 (2014/06/10)
A palladium-catalyzed, intermolecular Heck-type coupling of alkyl iodides and alkenes is described. This process is successful with a variety of primary and secondary unactivated alkyl iodides as reaction partners, including those with hydrogen atoms in t
Wadsworth-Emmons reaction: The unique catalytic reaction by a solid base
Choudary, Boyapati M.,Kantam, Mannepalli L.,Reddy, Chinta Reddy V.,Bharathi, Balagam,Figueras, Francois
, p. 191 - 200 (2007/10/03)
The near-stoichiometric amount of bases is used both in laboratory and industry in Wadsworth-Emmons (WE) reactions, since the by-product, (EtO) 2P(O)OH, formed in the reaction neutralizes the base into an inert salt. A strategy to design, develop, and evolve the recyclable Mg-Al-hydrotalcite-OtBu (HT-OtBu) by the interaction of KOtBu with the calcined hydrotalcite that transforms a well-defined stoichiometric WE reaction into a catalytic one in an effort to minimize the quantum of effluents released and reduce the cost of the process is described here. HT-OtBu is found to be an efficient solid base for WE reactions for the simple synthesis of α,β-unsaturated esters and nitriles for the first time. The HT-OtBu, composed of various ratios of Mg/Al (i.e., 2, 2.5, and 3) and different contents of tBuO - (Mg/Al:3), and their precursors were prepared and well characterized to draw a correlation between structure and reactivity of the hydrotalcites in WE reactions.
Wittig reaction using perfluorinated ylides
Galante, Aurélie,Lhoste, Paul,Sinou, Denis
, p. 5425 - 5427 (2007/10/03)
Wittig reactions could be performed in perfluorosolvents using perfluorinated ylides, allowing both a very easy separation of the alkene from the phosphine oxide and a re-use of the latter by simple reduction of the crude oxide.
P(RNCH2CH2)3N-Catalyzed synthesis of β-hydroxy nitriles
Kisanga, Philip,McLeod, Dale,D'Sa, Bosco,Verkade, John
, p. 3090 - 3094 (2007/10/03)
We herein report the successful synthesis of β-hydroxy nitriles in very good to excellent yields from aldehydes and ketones in a simple reaction that is promoted by strong nonionic bases of the title type. The reaction occurs in the presence of magnesium salts which activate the carbonyl group and stabilizes the enolate thus produced.
Synthesis and antiallergy activity of [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-one derivatives. II. 6-Alkyl- and 6-cycloalkylalkyl derivatives
Yokohama,Miwa,Aibara,Fujiwara,Matsumoto,Nakayama,Iwamoto,Mori,Moroi,Tsukada,Isoda
, p. 2391 - 2398 (2007/10/02)
A series of 6-alkyl- or 6-(cycloalkylalkyl)-[1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyr imidin-9(3H)-ones 1b-o was synthesized from the corresponding 1,3,4-thiadiazol-5-amines 3b-o and the antiallergic activities of the products were evaluated. Among the compounds 6-(2-cyclohexylethyl)-[1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]p yrimidin-9(3H)-one 1h, whose X-ray crystallographic stereostructure is shown, was found to be a promising new antiallergic agent, which has low toxicity and dual activity as a leukotriene D4 receptor antagonist and as an orally active mast cell stabilizer.
Tertiary Carbinamines by Addition of Organocerium Reagents to Nitriles and Ketimines
Ciganek, Engelbert
, p. 4521 - 4527 (2007/10/02)
Organocerium reagents, prepared by reaction of aromatic and primary and secondary alkyllithium reagents with anhydrous cerium chloride, add to nitriles twice to give tertiary carbinamines in often excellent yields.Addition of n-BuCeCl2 to acetophenone is about 4 times faster than addition to benzonitrile.Only 1,2-diaddition is observed in the reaction of MeCeCl2 with cinnamonitrile.The species formed in the double addition of organocerium reagents to nitriles are sufficiently basic to generate a benzyne intermediate by abstraction of an aromatic proton and nucleophilic enough to undergo an intramolecular Chichibabin reaction.Reaction of N-unsubstituted ketimines or their lithium salts with organocerium reagents permits the synthesis of tertiary carbinamines with three different groups on the tertiary carbon center.
Dimeric Metal Complexes as Mediator for Radical C-C Bond-Forming Reactions
Giese, Bernd,Thoma, Gebhard
, p. 1135 - 1142 (2007/10/02)
Irradiation of dicarbonyl(η5-cyclopentadienyl)iron dimer 1 or decacarbonyldimanganese (2) in the presence of alkyl halides leads to C-centered radicals which can be trapped by alkenes and yields saturated and/or unsaturated addition products.Carbon radicals are generated via halogen abstraction by the initially formed metal-centered radicals resulting from homolysis of the metal-metal bond of dimeric mediators 1 and 2.No reaction occurs using octacarbonyl dicobalt (3).
