4471-22-1Relevant academic research and scientific papers
Temporal control in tritylation reactions through light-driven variation in chloride ion binding catalysis-a proof of concept
Bari, Naimat K.,Grewal, Surbhi,Kumar, Himanshu,Roy, Saonli,Saraswat, Mayank,Sinha, Sharmistha,Venkataramani, Sugumar
, p. 7027 - 7033 (2020/11/09)
Tripodal triazole-linked azo(hetero)arene-based photoswitchable catalysts T1-5 have been designed, synthesized and optimized for the tritylation reaction of benzylamine (BzNH2). The tritylation reaction rates/yields achieved by light induced isomerization are compared between the native and photoswitched states of the catalyst T1. This concept of controlling the tritylation reaction rates with light has also been extended to additional substrates. The critical role of the triazole C-H?Cl- interactions has been confirmed by a combination of spectroscopic, calorimetric and computational studies. Also, the effect of variation in the binding affinities between the native and photoswitched states of the catalyst at room temperature in the temporal control of the catalysis has been demonstrated. This journal is
Remarkable Structural Diversity between Zr/Hf and Rare-Earth MOFs via Ligand Functionalization and the Discovery of Unique (4, 8)-c and (4, 12)-connected Frameworks
Angeli, Giasemi K.,Batzavali, Danai,Mavronasou, Katerina,Tsangarakis, Constantinos,Stuerzer, Tobias,Ott, Holger,Trikalitis, Pantelis N.
supporting information, p. 15986 - 15994 (2020/10/18)
Ligand modification in MOFs provides great opportunities not only for the development of functional materials with new or enhanced properties but also for the discovery of novel structures. We report here that a sulfone-functionalized tetrahedral carboxylate-based ligand is capable of directing the formation of new and fascinating MOFs when combined with Zr4+/Hf4+ and rare-earth metal cations (RE) with improved gas-sorption properties. In particular, the resulting M-flu-SO2 (M: Zr, Hf) materials display a new type of the augmented flu-a net, which is different as compared to the flu-a framework formed by the nonfunctionalized tetrahedral ligand. In terms of properties, a remarkable increase in the CO2 uptake is observed that reaches 76.6% and 61.6% at 273 and 298 K and 1 bar, respectively. When combined with REs, the sulfone-modified linker affords novel MOFs, RE-hpt-MOF-1 (RE: Y3+, Ho3+, Er3+), which displays a fascinating (4, 12)-coordinated hpt net, based on nonanuclear [RE9(μ3-?)2(μ3-??-)12(-COO)12] clusters that serve as hexagonal prismatic building blocks. In the absence of the sulfone groups, we discovered that the tetrahedral linker directs the formation of new RE-MOFs, RE-ken-MOF-1 (RE: Y3+, Ho3+, Er3+, Yb3+), that display an unprecedented (4, 8)-coordinated ken net based on nonanuclear RE9-clusters, to serve as bicapped trigonal prismatic building units. Successful activation of the representative member Y-ken-MOF-1 reveals a high BET surface area and total pore volume reaching 2621 m2 g-1 and 0.95 cm3 g-1, respectively. These values are the highest among all RE MOFs based on nonanuclear clusters and some of the highest in the entire RE family of MOFs. The present work uncovers a unique structural diversity existing between Zr/Hf and RE-based MOFs that demonstrates the crucial role of linker design. In addition, the discovery of the new RE-hpt-MOF-1 and RE-ken-MOF-1 families of MOFs highlights the great opportunities existing in RE-MOFs in terms of structural diversity that could lead to novel materials with new properties.
Symmetry-guided synthesis of highly porous metal-organic frameworks with fluorite topology
Zhang, Muwei,Chen, Ying-Pin,Bosch, Mathieu,Gentle III, Thomas,Wang, Kecheng,Feng, Dawei,Wang, Zhiyong U.,Zhou, Hong-Cai
supporting information, p. 815 - 818 (2014/01/23)
Two stable, non-interpenetrated MOFs, PCN-521 and PCN-523, were synthesized by a symmetry-guided strategy. Augmentation of the 4-connected nodes in the fluorite structure with a rigid tetrahedral ligand and substitution of the 8-connected nodes by the Zr/Hf clusters yielded MOFs with large octahedral interstitial cavities. They are the first examples of Zr/Hf MOFs with tetrahedral linkers. PCN-521 has the largest BET surface area (3411 m 2 g-1), pore size (20.5×20.5×37.4 A?) and void volume (78.5%) of MOFs formed from tetrahedral ligands. This work not only demonstrates a successful implementation of rational design of MOFs with desired topology, but also provides a systematic way of constructing non-interpenetrated MOFs with high porosity. Meet me at the symmetry gates: Using a symmetry-guided design strategy, two stable, non-interpenetrated MOFs, were synthesized by augmenting the fluorite topology with tetrahedral linkers, thus expanding the cavity size (see scheme) and giving the largest pore size of any MOF with tetrahedral ligands. Copyright
Design, synthesis and identification of a new class of triarylmethyl amine compounds as inhibitors of apolipoprotein e production
Singh, Mandeep,Schott, Jason T.,Leon, Martin A.,Granata, Robert T.,Dhah, Harkiran K.,Welles, Jason A.,Boyce, Michelle A.,Oseni-Olalemi, Hafeez S.,Mordaunt, Charles E.,Vargas, Anthony J.,Patel, Nilay V.,Maitra, Santanu
, p. 6252 - 6255 (2012/10/29)
We have identified a new class of triarylmethyl amine compounds that can inhibit apolipoprotein E (apoE) production. ApoE is a cholesterol- and lipid-carrier protein implicated in aging, atherosclerosis, Alzheimer's Disease (AD), and other neurological and lipid-related disorders. Attenuation of apoE production is generally considered to be of therapeutic value. A majority of the apoE in the brain is produced by astrocytes. Here, we describe the design, synthesis, and biological screening of a small library of compounds that led to the identification of four triarylmethyl amines as potent inhibitors of apoE production in CCF-STTG1 astrocytoma cells.
Transition-metal-free direct arylation of anilines
Pirali, Tracey,Zhang, Fengzhi,Miller, Anna H.,Head, Jenna L.,McAusland, Donald,Greaney, Michael F.
supporting information; experimental part, p. 1006 - 1009 (2012/02/16)
Aryne arylation: A new method of direct arylation is reported for aniline substrates. The reaction uses benzyne to synthesize a variety of aminobiaryls under mild conditions (see scheme), requiring no stoichiometric metalation or transition-metal catalysis. An ene mechanism is implicated, and conveys excellent functional group tolerance relative to metal-mediated processes. Copyright
Ceric ammonium nitrate-mediated detritylation of tritylated amines
Pattanayak, Sankha,Sinha, Surajit
supporting information; experimental part, p. 34 - 37 (2011/02/25)
Efficient deprotection of tritylated amines to the corresponding amines mediated by 20 mol % ceric ammonium nitrate [Ce(NH4) 2(NO3)6, CAN], 10 equiv of acetic acid and 15 equiv of water in dichloromethane is presented. This method equally worked well in the case of morpholino nucleosides.
Preparations, X-ray crystal structure determinations, and base strength measurements of substituted tritylamines
Canle, Moises L.,Clegg, William,Demirtas, Ibrahim,Elsegood, Mark R.J.,Maskill, Howard
, p. 85 - 92 (2007/10/03)
A range of tritylamines TrNRR′, and 4-methoxy-, 4,4′-dimethoxy-, and 4,4′,4″-trimethoxy-substituted analogues, have been prepared from (substituted) trityl chloride, bromide, or tetrafluoroborate with ammonia or with amines HNRR′ where R and R′ are hydrog
Synthesis of N- and p-(Diphenylmethyl)anilines. ESR Study of their Photofragmentation
Siskos, Michael G.,Garas, Stylianos K.,Zarkadis, Antonios K.,Bokaris, Efthymios P.
, p. 2477 - 2482 (2007/10/02)
The reaction of N-substituted anilines 2 with diphenylmethyl halides 1 at room temperature in the presence of AlCl3 affords p-substituted derivatives 3 in good yields according to an electrophilic aromatic substitution.In contrast, aniline itself is only converted to the N-substituted compounds 4.A novel rearrangement from Ph3C-NHPh (4c) to p-(triphenylmethyl)aniline (5) is described.Unexpected photofragmentations of 4a, b are studied by using ESR and ENDOR spectroscopy; e.g., irradiation of 4b with quartz- or pyrex-filtered light leads to the formation of the radicals Ph2C-SiMe3 (7b) and Ph2C-NHPh (6) respectively, following selective cleavage of the C-N and C-Si bond.Key Words: Benzenamine derivatives, synthesis of / Rearrangement, Hofmann-Martius / Diphenylmethyl radicals / ESR measurements / ENDOR measurements
