112633-26-8Relevant articles and documents
Template-directed synthesis of mechanically interlocked molecular bundles using dynamic covalent chemistry
Northrop, Brian H.,Arico, Fabio,Tangchiavang, Nick,Badjic, Jovica D.,Stoddart, J. Fraser
, p. 3899 - 3902 (2006)
Mixing the dipyrido[24]crown-8 derivatives carrying one or two formyl group(s) on the 4 position(s) of their pyridine ring(s) with a 3-fold symmetrical trisammonium ion template in a 3:1 ratio in CD3NO 2 results in the formation of t
Synthesis, structural aspects, antimicrobial activity and ion transport investigation of five new [1+1] condensed cycloheterophane peptides
Zaim, Oemer,Aghatabay, Naz Mohammed,Guerbuez, Mustafa Ulvi,Baydar, Caglar,Duelger, Basaran
, p. 151 - 159 (2014)
Five novel [1+1] condensed cycloheterophane peptides were synthesized via reaction of pyridine-2,6-bis(2-aminothiophenoxymethyl) with several diacid chlorides: glutaryl dichloride, adipoyl dichloride, 2,2′-thiodiacetyl chloride, dithiodiglycoloyl chloride and 3,3′-thiodipropionoyl chloride combinations (L 1 -L 5 ). The compounds were characterized by elemental analyses, mass, FT-IR, 1H, and 13C NMR spectral data. The antimicrobial activities of the compounds were evaluated using the disk diffusion method in dimethyl sulfoxide as well as the minimal inhibitory concentration dilution method, against several bacteria and yeast cultures. The results were compared with those of commercial antibiotic and antifungal agents. Structure activity relationships were also discussed. Permeability of compound L 5 against Na+ and K+ were also investigated. Graphical abstract: Five novel cycoloheterophane amides were synthesized. Mass spectra reveal their [1+1] cyclic condensation. The compounds exert moderate microbial activity. Thia and aza groups seem to be a key element of microbial potency.[Figure not available: see fulltext.]
Group 12 Metal Complexes of an 18-Membered N2O2S2 Macrocycle Incorporating Two Pyridines: First Examples of an Infinite Mercury(I) Complex and a Dumbbell-Shaped Heteronuclear Complex with a Macrocyclic Ligand
Seo, Sujin,Ju, Huiyeong,Kim, Seulgi,Park, In-Hyeok,Lee, Eunji,Lee, Shim Sung
, p. 11028 - 11039 (2016)
Homo- and heteronuclear group 12 metal (Zn2+, Cd2+, and Hg2+) complexes 1-6 containing a newly designed 18-membered N2O2S2 macrocycle incorporating two pyridine subunits (L) were prepared a
New advances in the synthesis of tripyridinophane macrocycles suitable to enhance the luminescence of Ln(III) ions in aqueous solution
Leygue, Nadine,Perez e I?iguez De Heredia, Aritz,Galaup, Chantal,Benoist, Eric,Lamarque, Laurent,Picard, Claude
, p. 4272 - 4287 (2018)
A series of four new 18-membered hexaaza macrocyclic ligands bearing three endocyclic pyridine units and acetate or methylenephosphonate pendant arms has been prepared. The new synthetic procedure is based on the use of amine and diamine precursors incorporating masked carboxylate or phosphonate functions and on an efficient sodium template effect which controls the crucial macrocyclization step (yields of macrocyclization reactions: 62–88%). This procedure appears as a suitable alternative compared to the classical Richman-Atkins methodology generally used for the preparation of this class of macrocycles. As demonstrated with the EuIII and TbIII complexes derived from two ligands, these tripyridinophane chelators form luminescent and stable mononuclear LnIII complexes in aqueous solution at physiological pH. In such a medium, TbIII complexes exhibit a brightness of 1700 (λexc = 279 nm) and 3000 (λexc = 268 nm) M?1 cm?1.
Switching from Ethylene Trimerization to Ethylene Polymerization by Chromium Catalysts Bearing SNS Tridentate Ligands: Process Optimization Using Response Surface Methodology
Soheili, Majid,Mohamadnia, Zahra,Karimi, Babak
, p. 3685 - 3700 (2018/10/15)
Two types of chromium catalysts bearing pyridine and amine based SNS ligands under the title of (pyridine-SNS-alkyl/CrCl3) and (amine-SNS-alkyl/CrCl3) were synthesized. Different thiolates such as octyl, pentyl, butyl, cyclohexyl and cyclopentyl thiolates were reacted with 2,6-pyridine-dimethylene-ditosylate (PMT)/THF solution at room temperature. Then, the purified pyridine-based SNS ligands (1–5) were reacted with CrCl3 (THF)3 to obtain the pyridine-SNS-alkyl/CrCl3 catalysts (6–10) in 50–70% yields. MMAO-activated pyridine-SNS-alkyl/CrCl3 catalysts were capable of oligomerizing ethylene. Statistical experimental design was conducted using the central composite design method and surface methodology to study of the effect of important parameters such as ethylene pressure, Al/Cr ratio, catalyst concentration and the reaction temperature on 1-C6 productivity of catalyst (7). A quadratic polynomial equation was developed to predict the 1-C6 productivity. Ethylene oligomerization using the catalyst (7) was lead to a optimized reaction conditions, including the ethylene pressure of 19.5?bar, the temperature of 58.2?°C, the MMAO co-catalyst, Al/Cr = 841 and the catalyst concentration of 8.7?μmol. The catalytic properties for ethylene oligomerization are strongly affected by reaction temperature. The experimental results indicated the reasonable agreement with the predicted values. The transformation from ethylene trimerization to ethylenev polymerization of catalyst system (7) was occurred by exchanging the reaction pressure. Influence of ligand structure with different substitutions on sulphur atom on productivity and selectivity was investigated. 1-C6 with the high selectivity and productivity 4318 (g 1-C6/g Cr h) was obtained for catalyst (7). In the second part, 1-C6 was obtained with high selectivity and productivity around 141 × 103 (g 1-C6/g Cr h) for amine-based catalyst. All amine-based catalysts (14–16) showed considerably higher catalytic activities compared to pyridine-based catalysts. According to the TGA analysis the thermal stability of pyridine-based catalysts was found to be higher than the amine-based catalysts. Graphical Abstract: Chromium complexes bearing pyridine and amine based SNS ligands have been synthesized and their catalytic performance in ethylene oligomerization has been investigated. A switching from ethylene trimerization to ethylene polymerization of the catalyst (7) was obtained utilizing exchanging of the ethylene pressure. [Figure not available: see fulltext.].
Tuning Catalytic Activity in the Hydrogenation of Unactivated Olefins with Transition-Metal Oxos as the Lewis Base Component of Frustrated Lewis Pairs
Lambic, Nikola S.,Sommer, Roger D.,Ison, Elon A.
, p. 1170 - 1180 (2017/08/09)
The steric and electronic demands of the catalytic olefin hydrogenation of tert-butylethylene with oxorhenium/Lewis acid FLPs were evaluated. The sterics of the ligand were altered by installing bulkier isopropyl groups in the 2,6-positions of the diamidopyridine (DAP) ligand. Lewis acid/base adducts were not isolated for complexes with this ligand; however, species incorporating isopropyl groups were still active in catalytic hydrogenation. Modifications were also made to the Lewis acid, and catalytic reactions were performed with Piers' borane, HB(C6F5)2, and the aluminum analogue Al(C6F5)3. The rate of catalytic hydrogenation was shown to strongly correlate with the size of the alkyl, aryl, or hydride ligand. This was confirmed by a linear Taft plot with the steric sensitivity factor δ = -0.57, which suggests that reaction rates are faster with sterically larger X substituents. These data were used to develop a catalyst ((MesDAP)Re(O)(Ph)/HB(C6F5)2) that achieved a TON of 840 for the hydrogenation of tert-butylethylene at mild temperatures (100 °C) and pressures (50 psi of H2). Tuning of the oxorhenium catalysts also resulted in the hydrogenation of tert-butylethylene at room temperature.
