10203-58-4Relevant articles and documents
FRUSTRATED LEWIS PAIR-IMPREGNATED POROUS MATERIALS AND USES THEREOF
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Page/Page column 73; 80-81, (2021/01/23)
Described herein are compositions composed of frustrated Lewis pairs impregnated in porous materials such as, for example, metal-organic frameworks, and their uses thereof. These compositions may allow new applications of frustrated Lewis pairs in catalysis by sequestering and protecting the frustrated Lewis pair within the nanospace of the porous material. Also provided are methods of hydrogenating an organic compound having at least one unsaturated functional group comprising using the compositions described herein.
Metal-Organic Framework Anchored with a Lewis Pair as a New Paradigm for Catalysis
Niu, Zheng,Bhagya Gunatilleke, Wilarachchige D.C.,Sun, Qi,Lan, Pui Ching,Perman, Jason,Ma, Jian-Gong,Cheng, Yuchuan,Aguila, Briana,Ma, Shengqian
, p. 2587 - 2599 (2018/12/02)
Lewis pair (LP) chemistry has shown broad applications in the catalysis field. However, one significant challenge has been recognized as the instability for most homogeneous LP catalysts upon recycling, thus inevitably leading to dramatic loss in catalytic activity. Additionally, current heterogeneous LP catalysts suffer from low surface area, which largely limits their catalytic efficiency, thereby restricting their potential applications. In this work, we report the successful introduction of LPs, classical and frustrated, into a metal-organic framework (MOF) that features high surface and ordered pore structure via a stepwise anchoring strategy. Not only can the LP be stabilized by the strong coordination interaction between the LP and MOF, but the resultant MOF-LP also demonstrates excellent catalysis performance with interesting size and steric selectivity. Given the broad applicability of LPs, our work therefore paves a way for advancing MOF-LP as a new paradigm for catalysis. Lewis pairs (LPs), classical and frustrated, are excellent prospects in catalysis, organic syntheses, biology, and material sciences. However, the instability of most LP catalysts leads to a dramatic loss in activities, thereby largely restricting their industrial applications. As robust porous materials, metal-organic frameworks (MOFs) offer a platform to stabilize homogeneous catalysts. Here, we show a strategy that grafts the LP catalyst on the MOF to minimize loss of LPs during catalysis and recycling. Our work reveals the enormous potential of MOFs as an appealing paradigm for the construction of efficient heterogeneous catalysts with interesting steric and size selectivity worthy of exploration. In addition, the strategies for anchoring a LP into a MOF as contributed herein can be readily applied for the task-specific design of functional catalysis materials for various applications. Lewis pairs (LPs), classical and frustrated, have been successfully introduced into and stabilized in a metal-organic framework (MOF). Benefiting from the robust framework and tunable porous structure of MOFs, the resultant MOF-LP demonstrates not only great recyclability but also excellent performance in the catalytic reduction of imines and hydrogenation of alkenes. The combination of LP and MOF therefore lays a foundation for developing a MOF-LP as a new paradigm for catalysis, particularly heterogeneous catalysis.
Functional examination of novel kisspeptin phosphinic peptides
Zhang, Xiaoyang,Matziari, Magdalini,Xie, Yixin,Fernig, David,Rong, Rong,Meng, Jia,Lu, Zhi-Liang
, (2018/04/12)
Kisspeptins acting on their cognate G protein-coupled receptor, kisspeptin receptor, play important roles in the suppression of cancer cell metastasis and regulation of the reproductive system, and therefore are important for therapeutic intervention. All native functional human kisspeptins (kisspeptin-54, kisspsptin-14 and kisspeptin-13) share the 10 amino acids of kisspeptin-10 at their C-terminus (45-54). However, they are inactivated rapidly by matrix metalloproteinases (MMPs) through the cleavage of the peptide bond between glycine 51 and leucine52, which limits their clinical applications. Development of MMP-resistant analogues of kisspeptins may provide better therapeutic outputs. In the present study, two kisspeptin phosphinic peptides were designed and synthesized, and their ability to induce phosphorylation of ERK1/2 through kisspeptin receptor and their inhibition on MMP-2 and MMP-9 whose activity correlates with cancer metastasis were assessed. The results showed that one analogue, phosphinic kisspeptin R isomer (PKPR), exhibited kisspeptin receptor-agonistic activity and also inhibitory activity on MMP-2, indicating that PKPR may serve as a lead for the further development of kisspeptin analogues for therapeutic purpose.
Palladium-Catalyzed Atom-Transfer Radical Cyclization at Remote Unactivated C(sp3)?H Sites: Hydrogen-Atom Transfer of Hybrid Vinyl Palladium Radical Intermediates
Ratushnyy, Maxim,Parasram, Marvin,Wang, Yang,Gevorgyan, Vladimir
supporting information, p. 2712 - 2715 (2018/03/02)
A novel mild, visible-light-induced palladium-catalyzed hydrogen atom translocation/atom-transfer radical cyclization (HAT/ATRC) cascade has been developed. This protocol involves a 1,5-HAT process of previously unknown hybrid vinyl palladium radical intermediates, thus leading to iodomethyl carbo- and heterocyclic structures.
A amide alkaloid fully synthetic method
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Paragraph 0080; 0081, (2017/08/25)
The invention discloses a total synthesis method of amides alkaloid, and belongs to the technical field of the chemistry of natural products. The total synthesis method comprises the following steps: carrying out the synthesis by adopting malonate and 2-bromopropane or 2-bromopropane derivative as raw materials, thereby obtaining isopropyl malonate; (2) carrying out the synthesis by adopting 2-aminopyrrolidine as a raw material, thereby obtaining mid-body 2-amino tetralin pyrrolidine; and (3) synthesizing amides alkaloid 3-isopropyl-nafoxidine[1,2-alpha]pyrimidine-2,4(1H,3H)-diketone and a derivative by adopting the isopropyl malonate and the 2-2-amino tetralin pyrrolidine as a raw material. By adopting the total synthesis method, the defect that the extraction separation process in the natural product is complicated and the yield is low can be overcome, and the demand of perople for further researching the natural product can be satisfied; moreover, the synthesis method is simple in route, raw materials are cheap and easy to obtain, and the yield is relatively high.
Creation through immobilization: A new family of high performance heterogeneous bifunctional iminophosphorane (BIMP) superbase organocatalysts
Goldys, Anna M.,Nez, Marta G.,Dixon, Darren J.
supporting information, p. 6294 - 6297 (2015/02/05)
An immobilized chiral bifunctional iminophosphorane superbase organocatalyst has been developed and applied in a range of challenging enantioselective reactions. A unique feature of this novel catalytic system is that the final step creation of the iminophosphorane occurs at the point of immobilization. The utility of the immobilized catalyst system was demonstrated in the nitro-Mannich reaction of ketimines as well as the conjugate addition of high pKa 1,3-dicarbonyl pro-nucleophiles to nitrostyrene. Catalyst recycling was also demonstrated.
Metal-free hydrogenation of electron-poor allenes and alkenes
Ines, Blanca,Palomas, David,Holle, Sigrid,Steinberg, Sebastian,Nicasio, Juan A.,Alcarazo, Manuel
supporting information, p. 12367 - 12369 (2013/02/22)
The poorer, the better: A metal-free catalytic procedure for the reduction of electron-poor allenes and alkenes has been developed. The method employs a frustrated Lewis pair based catalyst. 1,4-Diazabicyclo[2.2.2]octane (DABCO)/B(C6F5)3 was shown to be the best combination in optimization studies. Copyright
Malonic acid based matrix metalloproteinase inhibitors
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, (2008/06/13)
There is described the use of a compound represented by general formulae (I), (II) or (III), for the inhibition of matrix metalloproteinases (MMP), wherein X1 is oxygen or sulfur, R1 is OH, SH, CH2OH, CH2SH or NHOH, R2 is a residue of 2 to 10 hydrocarbon backbone atoms, which binds to the amino acid 161 of HNC, said residue being saturated or unsaturated, linear or branched, and contains preferably homocyclic or heterocyclic structures, X2 is oxygen or sulfur and binds as hydrogen acceptor on amino acid 160 of HNC, Y is a residue which binds to the S1′ pocket of HNC and consists of at least 4 backbone atoms Z1-Z2-Z3-Z4-R3, and R3 is n-propyl, isopropyl, isobutyl or a residue with at least 4 backbone atoms, which is not larger than a tricyclic ring system. These compounds bind to MMPs in a manner different from the mode of binding of the inhibitors of the state of the art.
Mixed Dialkylaluminum Chlorides and Mixed Trimethylorganoaluminates in Chemoselective 1,4 Addition Reactions to Alkylidene Malonic Acid Diethyl Ester
Maas, Steffen,Kunz, Horst
, p. 396 - 403 (2007/10/03)
Mixed alkyl-methyl- and aryl-methylorganoaluminum chlorides 6 were formed by reaction of methylaluminum dichloride with organolithium or Grignard compounds and used for chemoselective 1,4 addition of higher alkyl, aryl, alkenyl and alkinyl groups to alkylidine malonic esters 1 and 2. As an alternative, mixed trimethylorganoaluminates 7 can also be applied for these Michael addition reactions. For conjugate addition of alkenyl groups to alkylidene malonates 1 and 2, alkenyl diisopropylalanes 10 obtained from alkynes and diisopropylaluminum hydride proved the most efficient reagents. Using these novel mixed organoaluminum compounds, β-branched malonic (carboxylic) acid derivatives 3c, 8, 9 and 11 were obtained in good yields. The method offers a general access to β-branched carboxylic derivatives of quite diverse structure not dependent on the commercial availability of the organoluminum chlorides.
Utilization of the 1,2,5-thiadiazolidin-3-one 1,1 dioxide scaffold in the design of potent inhibitors of serine proteases: SAR studies using carboxylates
Kuang, Rongze,Epp, Jeffrey B.,Ruan, Sumei,Chong, Lee S.,Venkataraman, Radhika,Tu, Juan,He, Shu,Truong, Tien M.,Groutas, William C.
, p. 1005 - 1016 (2007/10/03)
A series of carboxylate derivatives based on the 1,2,5-thiadiazolidin-3- one 1,1 dioxide and isothiazolidin-3-one 1,1 dioxide scaffolds has been synthesized and the inhibitory profile of these compounds toward human leukocyte elastase (HLE), cathepsin G (Cat G) and proteinase 3 (PR 3) was then determined. Most of the compounds were found to be potent, time- dependent inhibitors of elastase, with some of the compounds exhibiting k(inact)/K(I) values as high as 4,928,300 M-1 s-1. The inhibitory potency of carboxylate derivatives based on the 1,2,5-thiadiazolidin-3-one 1,1 dioxide platform was found to be influenced by both the pK(a) and the inherent structure of the leaving group. Proper selection of the primary specificity group (R1) was found to lead to selective inhibition of HLE over Cat G, however, those compounds that inhibited HLE also inhibited PR 3, albeit less efficiently. The predictable mode of binding of these compounds suggests that, among closely-related serine proteases, highly selective inhibitors of a particular serine protease can be fashioned by exploiting subtle differences in their S' subsites. This study has also demonstrated that the degradative action of elastase on elastin can be abrogated in the presence of inhibitor 17. (C) 2000 Elsevier Science Ltd.
