604-53-5Relevant articles and documents
Dynamics of Atropisomerization of 1,1'-Binaphtyl in Several Nematic Solvents. Rate Enhancement by a Solid Phase
Naciri, Jaouad,Spada, Gian Pierro,Gottarelli, Giovanni,Weiss, Richard G.
, p. 4352 - 4357 (1987)
The rates of atropisomerization of (S)-1,1'-binaphtyl (BN) are compared in six nematic phases and in the solid phase of p-methoxybenzylidene-p-n-butylaniline.The influence of each phase on the activation parameters for atropisomerization are correlated with the solvent molecular structures.The results in the nematic and solid phases are interpreted in terms of degree to which the solvent matrices flatten the angle between the naphtyl rings of BN.
-
Smith
, (1877)
-
Origin of the excellent catalytic activity of Pd loaded on ultra-stable y zeolites in Suzuki-Miyaura reactions
Okumura, Kazu,Tomiyama, Takuya,Okuda, Shizuyo,Yoshida, Hiroyuki,Niwa, Miki
, p. 156 - 166 (2010)
Suzuki-Miyaura reactions were performed over Pd loaded on (ultra-stable Y) USY zeolites prepared by steam treatment of NH4-Y. We found that the catalytic activity of Pd increased significantly with steam treatment of NH 4-Y when 6% H2 was applied before and during the reactions. For instance, a TON of 13,000,000 was obtained in the reaction between bromobenzene and phenylboronic acid in 1.5 h. Pd K-edge and Pd L 3-edge X-ray absorption fine structure analyses revealed the formation of atomic Pd with a cationic character. The catalytic activity of Pd/USY prepared under different steam-treatment conditions was in good correlation with the strong Bronsted acid sites induced by the extra-framework Al. Based on the catalytic performance data, the structure of Pd, and acidic analysis of the support, atomic Pd anchored to the strong Bronsted acid sites of the USY zeolite was proposed to be the active species.
Structures and photoluminescence of Silver(I) and Gold(I) cyclic trinuclear complexes with aryl substituted pyrazolates
Saotome, Mai,Shimizu, Daichi,Itagaki, Ayaka,Young, David James,Fujisawa, Kiyoshi
, p. 533 - 536 (2019)
The 4-aryl substituted pyrazolate ligands, L1(Ph)H and L1(Naph)H, were synthesized by SuzukiMiyaura cross-coupling and combined with metal sources to give cyclic trinuclear structures [AgL1(Ph)]3, [AuL1(Ph)] 3, [AgL1(Naph)] 3, and [AuL1(Naph)]3. The aryl group determined the crystal packing of these cyclic trinuclear complexes with the phenyl systems exhibiting stair type solid state structures and the naphthyl complexes exhibiting irregular structures with spaces occupied with some solvent molecules. These differences in solid-state structures were accompanied by differences in MN stretching frequencies and temperature dependent photoluminescence.
Deracemization of a Racemic Compound by Using Tailor-Made Additives
Engwerda, Anthonius H. J.,van Schayik, Pim,Jagtenberg, Henjo,Meekes, Hugo,Rutjes, Floris P. J. T.,Vlieg, Elias
, p. 2863 - 2867 (2018)
Viedma ripening is a process that combines abrasive grinding of a slurry of crystals with solution-phase racemization, resulting in solid-phase deracemization. One of the major disadvantages of Viedma ripening is that the desired compound needs to crystallize as a racemic conglomerate, accounting for only 5–10 % of all chiral molecules. Herein, we show that use of a chiral additive causes deracemization under conditions, in which the compound normally crystallizes as a racemic compound. Although this concerns a single example, it is envisioned that through this new approach the scope of Viedma ripening can be significantly expanded.
Suzuki homo-coupling reaction based fluorescent sensors for monosaccharides
Xu, Su-Ying,Wang, Hui-Chen,Flower, Stephen E.,Fossey, John S.,Jiang, Yun-Bao,James, Tony D.
, p. 35238 - 35241 (2014)
Palladium catalysed, aryl boronic acid homocoupling, is explored as a fluorescence sensing regime for saccharides. The catalytic formation rate of fluorescent bi-aryls, under control of a palladium catalyst, is modulated by the presence of saccharides. The nature of the aryl group, rate of biaryl formation and limits of detection are investigated.
Grignard reagent dictated copper(I) phosphines catalyzed reductive coupling of diazo compounds: The chemistry beyond carbene generation
Kuzhalmozhi Madarasi, Packirisamy,Sivasankar, Chinnappan
, (2021/12/01)
Copper-dppf catalyzed reductive coupling of diazo compounds through terminal nitrogen is reported. However, copper catalysts are known to produce carbene from diazo compounds; the reaction conditions played an important role in the formation of diazine over carbene generation. Several control experiments have been conducted to understand the reaction mechanism and found that the formation of a copper–Mg heterobimetallic complex would be responsible for the observed reactivity pattern. The reaction produced diazine as a reductive coupling product along with biphenyl as a by-product. All the synthesized diazines have been characterized fully by using analytical and spectroscopic techniques.
MeOTf-catalyzed formal [4?+?2] annulations of styrene oxides with alkynes leading to polysubstituted naphthalenes through sequential electrophilic cyclization/ring expansion
Chen, Chao,Xi, Chanjuan,Zhang, Zeyu,Zou, Song
supporting information, (2021/12/30)
MeOTf-catalyzed formal [4 + 2] annulation of styrene oxides with alkynes to afford polysubstituted naphthalenes has been realized, which undergoes sequential electrophilic cyclization/ring expansion. A range of substrates were tolerated in the formation of naphthalene derivatives with high regioselectivity in satisfactory yields. The reaction could also be carried out on gram scale.
Tandem Mn–I Exchange and Homocoupling Processes Mediated by a Synergistically Operative Lithium Manganate
Uzelac, Marina,Mastropierro, Pasquale,de Tullio, Marco,Borilovic, Ivana,Tarrés, Màrius,Kennedy, Alan R.,Aromí, Guillem,Hevia, Eva
supporting information, p. 3247 - 3253 (2020/12/11)
Pairing lithium and manganese(II) to form lithium manganate [Li2Mn(CH2SiMe3)4] enables the efficient direct Mn–I exchange of aryliodides, affording transient (aryl)lithium manganate intermediates which in turn undergo spontaneous C?C homocoupling at room temperature to furnish symmetrical (bis)aryls in good yields under mild reaction conditions. The combination of EPR with X-ray crystallographic studies has revealed the mixed Li/Mn constitution of the organometallic intermediates involved in these reactions, including the homocoupling step which had previously been thought to occur via a single-metal Mn aryl species. These studies show Li and Mn working together in a synergistic manner to facilitate both the Mn–I exchange and the C?C bond-forming steps. Both steps are carefully synchronized, with the concomitant generation of the alkyliodide ICH2SiMe3 during the Mn–I exchange being essential to the aryl homocoupling process, wherein it serves as an in situ generated oxidant.
