2049-80-1Relevant articles and documents
Reaction of tetracarbonyl(π-allyl)manganese with carbon nucleophiles
Vaughan, William S.,Gu, Henry H.,McDaniel, Keith F.
, p. 1885 - 1888 (1997)
Nucleophilic attack on tetracarbony (π-allyl)manganese takes place at the terminus of the π-system, generating allylated products in 44-95% yield after oxidation. Stabilized nucleophiles (pK(a) 12-20) give mainly bis allylation whereas nonstabilized nucleophiles (pKa 25-35) give mono allylation.
Reactions d'alkylation de Fe(CO)2(NO) (η3-propenyl) par des nucleophiles carbones. Nature de l'intermediaire reactionnel
Roustan, Jean-Louis A.,Houlihan, Francois
, p. 215 - 220 (1988)
Decomposition of the intermediate resulting from the reaction of Fe(CO)2(NO)(η3-propenyl) (1) with a nucleophile -CH(CO2Et) (A) (2i A=CO2Et, i=1; A=CN, i=2) has been carried out under a variety of conditions using in particular two nucleophiles added, respectively, before and after the formation of the intermediate.The composition of the mixture of alkylation products obtained suggests that reaction of 1 with 2i is reversibly by complexation of the nucleophile with a concomitant η3 to η1 conversion of the allyl ligand.
2-Functionalized allyl tris(trimethylsilyl)silanes as radical-based allylating agents
Chatgilialoglu, Chryssostomos,Ferreri, Carla,Ballestri, Marco,Curran, Dennis P.
, p. 6387 - 6390 (1996)
Radical allylations with 2-functionalized allyl tris(trimethylsilyl)silanes occur under mild conditions in good to excellent yield provided that the radical precursor and the silane have the appropriate electronic pairing. These reactions offer tin-free alternatives for transformations that are currently conducted with allyl stannenes.
Synthesis and bactericidal evaluation of imide N-halamine-loaded PMMA nanoparticles
Dong, Qigeqi,Cai, Qian,Gao, Yangyang,Zhang, Shiqi,Gao, Ge,Harnoode, Chokto,Morigen,Dong, Alideertu
, p. 1783 - 1791 (2015)
Imide N-halamine-loaded poly(methyl methacrylate) nanoparticles (PMMA) based on barbituric acid were synthesized as novel antimicrobial agents using radical copolymerization. Evidence for loading imide N-halamine on PMMA nanoparticles has been inferred from different techniques like 1H NMR, FTIR, TEM, SEM, and XPS analyses. The sterilizing effect of the products on bacterial strains was systematically evaluated by selecting Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa as model pathogenic bacteria. The zone of inhibition study and the spread plate technique suggested that the imide N-halamine-loaded PMMA nanoparticles possessed powerful bactericidal activity towards both Gram-positive and Gram-negative bacteria. The effects of contact period, N-halamine structure, particle size, and chlorine content on biocidal efficiency were investigated as well. Long-term stability of the imide N-halamine-loaded PMMA nanoparticles was also confirmed as a function of storage period.
Phase-transfer Tsuji—Trost allylation of CH-acids with the assistance of palladium complexes with bidentate PIII—N—PIII ligands
Vasil′ev,Aladzheva,Bykhovskaya
, p. 661 - 665 (2017)
The Tsuji—Trost allylation of CH acids, in particular, those of the YCH2CO2Et type (Y = CO2Et, C(O)Me, CN), with allylic acetates in the K2CO3—DMF system in the presence of palladium catalysts with ligands RN(PPh2)2 (R = Ph, Pri, c-C6H11) is accomplished.
Silicon-Controlled Allylation of 1,3-Dioxo Compounds by Use of Allyltrimethylsilane and Ceric Ammonium Nitrate
Hwu, Jih Ru,Chen, Chung Nan,Shiao, Shui-Sheng
, p. 856 - 862 (1995)
A new method was developed for allylation of 1,3-diketones, β-keto esters, and malonates.Treatment of those 1,3-dioxo compounds with allyltrimethylsilane (1.3 equiv) in the presence of ceric ammonium nitrate (2.1 equiv) in methanol at room temperature often gave the mono-C-allylated products in good to excellent yields (74-98percent).These reactions, involving β-carboradical and β-carbocationic intermediates, were controlled by a silyl group.Replacement of ceric ammonium nitrate and methanol with manganese(III) acetate (2.4 equiv) and acetic acid afforded silicon-containing dihydrofurans in high yields at 80 deg C.
Copper-catalyzed cascade annulation of unsaturated α-bromocarbonyls with enynals: A facile access to ketones from aldehydes
Che, Chao,Huang, Qianwen,Zheng, Hanliang,Zhu, Gangguo
, p. 4134 - 4139 (2016)
A Cu-catalyzed cascade annulation of enynals with alkenyl or alkynyl α-bromocarbonyls for the synthesis of various cyclohexenone-fused polycyclic compounds is described. Up to six new C-C bonds and four new carbocycles can be established in a single reaction, highlighting the high efficiency and step-economics of this protocol. This reaction offers a novel and straightforward entry to the synthesis of ketones featuring the addition of carbon radicals to aldehydes.
GEM-disubstituent effects in small ring formation: Novel ketal ring size effect
Jung, Michael E.,Marquez, Rodolfo
, p. 6521 - 6524 (1997)
While reaction of the bromoalkene with a 5-membered ketal 6a with tributyltin hydride gave only the acyclic product 18a, reaction of the corresponding bromoalkene with a 6-membered ketal 6b gave good yields of the cyclobutane 17b, in a novel ketal ring size effect. Also the gem-dicarboalkoxy effect was operative in these systems, e.g., cyclization of the bromo alkene triester 11a afforded reasonable yields of the cyclobutane 19.
Palladium(II) aminoiminophosphoranate complexes as cross-coupling catalysts
Peganova,Kalsin,Ustynyuk,Vasil'Ev
, p. 2305 - 2308 (2014)
The Tsuji-Trost reaction between diethyl malonate and allyl acetate catalyzed by palladium(II) NPN-aminoiminophosphoranate complexes yields mono- and diallylation products in the ratios depending on the complex used. The Suzuki-Miyaura cross-coupling of 4-bromoacetophenone with phenylboronic acid catalyzed by these palladium complexes proceeds with 66-99.5% conversions.
Asymmetric allylic alkylation in supercritical carbon dioxide using P*-chiral diamidophosphite ligands
Lyubimov, Sergey E.,Kuchurov, Ilya V.,Vasil'Ev, Andrei A.,Zlotin, Sergei G.,Davankov, Vadim A.
, p. 143 - 144 (2010)
P*-Chiral diamidophosphite ligands in the Pd-catalyzed allylic alkylation of (E)-1,3-diphenylallyl acetate in supercritical carbon dioxide provide enantioselectivities up to 90% ee. The catalytic performance is affected greatly by temperature, CO2 pressures and structure of catalysts.
ALLYLIC ALKYLATION CATALYZED BY THE COUPLE PALLADIUM COMPLEXES-ALUMINA
Ferroud, D.,Genet, J.P.,Muzart, J.
, p. 4379 - 4382 (1984)
Using both palladium complexes and alumina, nucleophilic substitutions of allyl acetate by various nucleophiles (pKa=5-13) are realized with good yields at room temperature without preformation of the corresponding carbanions.
Nucleophilic Addition to π-Allyl Gold(III) Complexes: Evidence for Direct and Undirect Paths
Bourissou, Didier,García-Rodeja, Yago,Holmsen, Marte Sofie Martinsen,Lavedan, Pierre,Mallet-Ladeira, Sonia,Miqueu, Karinne,Rodriguez, Jessica,Sosa Carrizo, E. Daiann
, p. 11568 - 11581 (2021/08/20)
π-Allyl complexes play a prominent role in organometallic chemistry and have attracted considerable attention, in particular the π-allyl Pd(II) complexes which are key intermediates in the Tsuji-Trost allylic substitution reaction. Despite the huge interest in π-complexes of gold, π-allyl Au(III) complexes were only authenticated very recently. Herein, we report the reactivity of (P,C)-cyclometalated Au(III) π-allyl complexes toward β-diketo enolates. Behind an apparently trivial outcome, i.e. the formation of the corresponding allylation products, meticulous NMR studies combined with DFT calculations revealed a complex and rich mechanistic picture. Nucleophilic attack can occur at the central and terminal positions of the π-allyl as well as the metal itself. All paths are observed and are actually competitive, whereas addition to the terminal positions largely prevails for Pd(II). Auracyclobutanes and π-alkene Au(I) complexes were authenticated spectroscopically and crystallographically, and Au(III) σ-allyl complexes were unambiguously characterized by multinuclear NMR spectroscopy. Nucleophilic additions to the central position of the π-allyl and to gold are reversible. Over time, the auracyclobutanes and the Au(III) σ-allyl complexes evolve into the π-alkene Au(I) complexes and release the C-allylation products. The relevance of auracyclobutanes in gold-mediated cyclopropanation was demonstrated by inducing C-C coupling with iodine. The molecular orbitals of the π-allyl Au(III) complexes were analyzed in-depth, and the reaction profiles for the addition of β-diketo enolates were thoroughly studied by DFT. Special attention was devoted to the regioselectivity of the nucleophilic attack, but C-C coupling to give the allylation products was also considered to give a complete picture of the reaction progress.
SeO2-Mediated Oxidative Transposition of Pauson-Khand Products
Dibrell, Sara E.,Maser, Michael R.,Reisman, Sarah E.
supporting information, p. 6483 - 6487 (2020/04/30)
Oxidative transpositions of bicyclic cyclopentenones mediated by selenium dioxide (SeO2) are disclosed. Treatment of Pauson-Khand reaction (PKR) products with SeO2 in the presence or absence of water furnishes di- and trioxidized cyclopentenones, respectively. Mechanistic investigations reveal multiple competing oxidation pathways that depend on substrate identity and water concentration. Functionalization of the oxidized products via cross-coupling methods demonstrates their synthetic utility. These transformations allow rapid access to oxidatively transposed cyclopentenones from simple PKR products.
