66323-99-7Relevant academic research and scientific papers
Kinetic enolate formation by lithium arylamide: Effects of basicity on selectivity
Xie, Linfeng,Vanlandeghem, Keith,Isenberger, Kurt M.,Bernier, Carolyn
, p. 641 - 643 (2003)
Five ketones R1COCH2R2 (1a-e) were enolized in tetrahydrofuran solvent employing lithium arylamides with different electron-withdrawing and -donating substituents on the phenyl ring (4a-e). Enolate selectivity is unaffecte
A stereoselective isomerization of allyl silyl ethers to (E)- Or (Z)-silyl enol ethers using cationic iridium complexes
Ohmura, Toshimichi,Shirai, Yasuo,Yamamoto, Yasunori,Miyaura, Norio
, p. 1337 - 1338 (1998)
A cationic indium complex, prepared via the hydrogenation of [Ir(cod)2]PF6-2PPr3 is found to be an excellent catalyst for the stereoselective isomerization of primary allyl silyl ethers to (E)-enol ethers and secondary all
Lithium hexamethyldisilazide-mediated enolizations: Influence of triethylamine on E/Z selectivities and enolate reactivities
Godenschwager, Peter F.,Collum, David B.
, p. 8726 - 8732 (2008)
Lithium hexamethyldisilazide (LiHMDS) in triethylamine (Et 3N)/toluene is shown to enolize acyclic ketones and esters rapidly and with high E/Z selectivity. Mechanistic studies reveal a dimer-based mechanism consistent with previous studies of
β-Diazocarbonyl Compounds: Synthesis and their Rh(II)-Catalyzed 1,3 C?H Insertions
Jiang, Liyin,Wang, Zhaofeng,Armstrong, Melanie,Suero, Marcos G.
supporting information, p. 6177 - 6184 (2021/02/01)
Herein, we describe the first electrophilic diazomethylation of ketone silyl enol ethers with diazomethyl-substituted hypervalent iodine reagents that gives access to unusual β-diazocarbonyl compounds. The potential of this unexplored class of diazo compounds for the development of new reactions was demonstrated by the discovery of a rare Rh-catalyzed intramolecular 1,3 C?H carbene insertion that led to complex cyclopropanes with excellent stereocontrol.
Lewis Acid-Catalyzed Carbofunctionalization of Uncommon C, N-Diacyliminium Ions: Controlling Regio- And Enantioselectivity
Brasholz, Malte,Bresien, Jonas,Frahm, Mario,Gronbach, Lisa Marie,Michalik, Dirk,Villinger, Alexander,Voss, Alice
supporting information, p. 7834 - 7838 (2021/10/20)
The tricyclic azepino[1,2-a]indole acetates 7, readily accessible by visible-light-driven catalytic photooxygenation of cyclohepta[b]indoles 1, are convenient precursors to novel and uncommon cyclic C,N-diacyliminium ions 3. We report here the first Lewis
The Cyclopropane Ring as a Reporter of Radical Leaving-Group Reactivity for Ni-Catalyzed C(sp3)-O Arylation
Mills, L. Reginald,Monteith, John J.,Dos Passos Gomes, Gabriel,Aspuru-Guzik, Alán,Rousseaux, Sophie A. L.
supporting information, p. 13246 - 13254 (2020/09/01)
The ability to understand and predict reactivity is essential for the development of new reactions. In the context of Ni-catalyzed C(sp3)-O functionalization, we have developed a unique strategy employing activated cyclopropanols to aid the design and optimization of a redox-active leaving group for C(sp3)-O arylation. In this chemistry, the cyclopropane ring acts as a reporter of leaving-group reactivity, since the ring-opened product is obtained under polar (2e) conditions, and the ring-closed product is obtained under radical (1e) conditions. Mechanistic studies demonstrate that the optimal leaving group is redox-active and are consistent with a Ni(I)/Ni(III) catalytic cycle. The optimized reaction conditions are also used to synthesize a number of arylcyclopropanes, which are valuable pharmaceutical motifs.
Synthesis of a Bolm's 2,2′-Bipyridine Ligand Analogue and Its Applications
Bedná?ová, Eva,Dra?ínsky, Martin,Malatinec, ?tefan,Císa?ová, Ivana,Lamaty, Frédéric,Kotora, Martin
supporting information, p. 2869 - 2878 (2018/08/17)
A new method of synthesis of an analogue of Bolm's 2,2′-bipyridine ligand based on the catalytic [2+2+2] cyclotrimerization of 1-halodiynes with nitriles was developed. Crucial step of the whole synthesis turned out to be homodimerization of a substituted 2-bromopyridine to the corresponding bipyridine, that was studied and optimized. The newly prepared bipyridine (S,S)-2 was then tested as a chiral ligand in metal-catalyzed enantioselective reactions. Out of the studied reactions the most promising results were obtained in epoxide ring opening (82% yield, 98% ee) and Mukaiyama aldol reaction (>96% yield, 99/1 dr, 92% ee). In the case of Mukaiyama-aldol reaction as well as in the Michael addition, novel ligand 2 proved its robustness compared to Bolm's ligand as it was less sensitive to the purity of used reagents. (Figure presented.).
Organosilicon Reducing Reagents for Stereoselective Formations of Silyl Enol Ethers from α-Halo Carbonyl Compounds
Pramanik, Suman,Rej, Supriya,Kando, Shun,Tsurugi, Hayato,Mashima, Kazushi
, p. 2409 - 2417 (2018/02/23)
Salt-free stereoselective synthesis of silyl enol ethers was achieved by treating α-halo carbonyl compounds with 2,3,5,6-tetramethyl-1,4-bis(trimethylsilyl)-1,4-dihydropyrazine. In this reaction, easily removable trimethylsilyl halides and 2,3,5,6-tetramethylpyrazine were generated as the reaction byproducts. Due to the inertness of the reaction byproducts, we found a one-pot transformation of the in situ generated silyl enol ethers into various α-functionalized carbonyls by reaction with Togni-II reagent or aldehydes.
A Solvent-Free Reaction for Silyl Enol Ethers Synthesis
Morozzi, Chiara,Rosati, Ornelio,Curini, Massimo,Lanari, Daniela
supporting information, p. 126 - 130 (2017/12/28)
Silyl enol ethers are extremely useful nucleophilic intermediates for chemical transformations because they are synthetically versatile substrates for a wide range of C-C bond-forming reactions. Here, we present a new, mild, and solvent-free procedure for the synthesis of silyl enol ethers that employs a catalytic amount of solid-supported base and an equimolar amount of N, O -(bistrimethylsilyl)acetamide as a silylating agent.
Stereoselective Ketone Rearrangements with Hypervalent Iodine Reagents
Malmedy, Florence,Wirth, Thomas
supporting information, p. 16072 - 16077 (2016/10/30)
The first stereoselective version of an iodine(III)-mediated rearrangement of arylketones in the presence of orthoesters is described. The reaction products, α-arylated esters, are very useful intermediates in the synthesis of bioactive compounds such as ibuprofen. With chiral lactic acid-based iodine(III) reagents product selectivities of up to 73 % ee have been achieved.
