- Guanosine Borate Hydrogel and Self-Assembled Nanostructures Capable of Enantioselective Aldol Reaction in Water
-
A guanosine-based hydrogel formed by the self-assembly of guanosine and 4-((l-prolinamide)methyl)phenylboronic acid was constructed. The G quartets were selectively stabilized by K+ ions to form a self-supporting transparent hydrogel. These guanosine-derived assemblies were used to catalyze the aldol reaction in water without any additives, affording desirable conversion and enantioselectivity of the product. The controlled assays of small-molecule components indicated that the stable assemblies were the definite species that achieved high enantioselective catalysis. The current catalytic system can be readily recovered by simple extraction and still acquired good performance of the reaction after four cycles.
- Chen, Zhaohang,Zhou, Pengcheng,Guo, Yuanxia,Anna, None,Bai, Jiakun,Qiao, Renzhong,Li, Chao
-
p. 2624 - 2631
(2022/02/16)
-
- Compound targeting to I-type PRMT and preparation method and application of compound
-
The invention relates to the technical field of chemical drugs, in particular to a compound targeting to I-type PRMT, and a preparation method and application thereof. The compound A and a pharmaceutically acceptable salt thereof belong to covalent inhibi
- -
-
Paragraph 0097-0098; 0103
(2020/03/11)
-
- General and selective synthesis of primary amines using Ni-based homogeneous catalysts
-
The development of base metal catalysts for industrially relevant amination and hydrogenation reactions by applying abundant and atom economical reagents continues to be important for the cost-effective and sustainable synthesis of amines which represent highly essential chemicals. In particular, the synthesis of primary amines is of central importance because these compounds serve as key precursors and central intermediates to produce value-added fine and bulk chemicals as well as pharmaceuticals, agrochemicals and materials. Here we report a Ni-triphos complex as the first Ni-based homogeneous catalyst for both reductive amination of carbonyl compounds with ammonia and hydrogenation of nitroarenes to prepare all kinds of primary amines. Remarkably, this Ni-complex enabled the synthesis of functionalized and structurally diverse benzylic, heterocyclic and aliphatic linear and branched primary amines as well as aromatic primary amines starting from inexpensive and easily accessible carbonyl compounds (aldehydes and ketones) and nitroarenes using ammonia and molecular hydrogen. This Ni-catalyzed reductive amination methodology has been applied for the amination of more complex pharmaceuticals and steroid derivatives. Detailed DFT computations have been performed for the Ni-triphos based reductive amination reaction, and they revealed that the overall reaction has an inner-sphere mechanism with H2metathesis as the rate-determining step.
- Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Jiao, Haijun,Murugesan, Kathiravan,Wei, Zhihong
-
p. 4332 - 4339
(2020/05/18)
-
- The Synthesis of Primary Amines through Reductive Amination Employing an Iron Catalyst
-
The reductive amination of ketones and aldehydes by ammonia is a highly attractive method for the synthesis of primary amines. The use of catalysts, especially reusable catalysts, based on earth-abundant metals is similarly appealing. Here, the iron-catalyzed synthesis of primary amines through reductive amination was realized. A broad scope and a very good tolerance of functional groups were observed. Ketones, including purely aliphatic ones, aryl–alkyl, dialkyl, and heterocyclic, as well as aldehydes could be converted smoothly into their corresponding primary amines. In addition, the amination of pharmaceuticals, bioactive compounds, and natural products was demonstrated. Many functional groups, such as hydroxy, methoxy, dioxol, sulfonyl, and boronate ester substituents, were tolerated. The catalyst is easy to handle, selective, and reusable and ammonia dissolved in water could be employed as the nitrogen source. The key is the use of a specific Fe complex for the catalyst synthesis and an N-doped SiC material as catalyst support.
- B?umler, Christoph,Bauer, Christof,Kempe, Rhett
-
p. 3110 - 3114
(2020/06/01)
-
- Para-Selective C-H Borylation of Common Arene Building Blocks Enabled by Ion-Pairing with a Bulky Countercation
-
The selective functionalization of C-H bonds at the arene para position is highly challenging using transition metal catalysis. Iridium-catalyzed borylation has emerged as a leading technique for arene functionalization, but there are only a handful of strategies for para-selective borylation, which operate on specific substrate classes and use bespoke ligands or catalysts. We describe a remarkably general protocol which results in para-selectivity on some of the most common arene building blocks (anilines, benzylamines, phenols, benzyl alcohols) and uses standard borylation ligands. Our strategy hinges upon the facile conversion of the substrates into sulfate or sulfamate salts, wherein the anionic arene component is paired with a tetrabutylammonium cation. We hypothesize that the bulk of this cation disfavors meta-C-H borylation, thereby promoting the challenging para-selective reaction.
- Mihai, Madalina T.,Williams, Benjamin D.,Phipps, Robert J.
-
supporting information
p. 15477 - 15482
(2019/10/11)
-
- MOF-derived cobalt nanoparticles catalyze a general synthesis of amines
-
The development of base metal catalysts for the synthesis of pharmaceutically relevant compounds remains an important goal of chemical research. Here, we report that cobalt nanoparticles encapsulated by a graphitic shell are broadly effective reductive amination catalysts. Their convenient and practical preparation entailed template assembly of cobaltdiamine- dicarboxylic acid metal organic frameworks on carbon and subsequent pyrolysis under inert atmosphere.The resulting stable and reusable catalysts were active for synthesis of primary, secondary, tertiary, and N-methylamines (more than 140 examples).The reaction couples easily accessible carbonyl compounds (aldehydes and ketones) with ammonia, amines, or nitro compounds, and molecular hydrogen under industrially viable and scalable conditions, offering cost-effective access to numerous amines, amino acid derivatives, and more complex drug targets.
- Jagadeesh, Rajenahally V.,Murugesan, Kathiravan,Alshammari, Ahmad S.,Neumann, Helfried,Pohl, Marga-Martina,Radnik, J?rg,Beller, Matthias
-
p. 326 - 332
(2017/09/28)
-
- Synthesis of boron-containing primary amines
-
In this study, boron-containing primary amines were synthesized for use as building blocks in the study of peptoids. In the first step, Gabriel synthesis conditions were modified to enable the construction of seven different aminomethylphenyl boronate esters in good to excellent yields. These compounds were further utilized to build peptoid analogs via an Ugi four-component reaction (Ugi-4CR) under microwave irradiation. The prepared Ugi-4CR boronate esters were then successfully converted to the corresponding boronic acids. Finally, the peptoid structures were successfully modified by cross-coupling to aryl/heteroaryl chlorides via a palladium-mediated Suzuki coupling reaction to yield the corresponding derivatives in moderate to good yields.
- Chung, Sheng-Hsuan,Lin, Ting-Ju,Hu, Qian-Yu,Tsai, Chia-Hua,Pan, Po-Shen
-
p. 12346 - 12367
(2013/11/06)
-
- Synthesis of amines with pendant boronic esters by borrowing hydrogen catalysis
-
Amine alkylation reactions of alcohols have been performed in the presence of boronic ester groups to provide products which are known to have use as molecular sensors. The boronic ester moiety could be present in either the alcohol or amine starting mate
- Ma, Winson M. J.,James, Tony D.,Williams, Jonathan M. J.
-
supporting information
p. 4850 - 4853
(2013/10/08)
-
- METHOD FOR THE PRODUCTION OF LOSARTAN
-
The invention relates to a novel method for the production of losartan, an imidazol derivative with the chemical name 2-n-butyl-4-chloro-5-hydroxymethyl-1-{[2'-(1H-tetrazol-5-yl)biphenyl-4-]methyl}imidazol and the pharmacologically active salts thereof. The invention also relates to novel intermediate products which are suitable for the production of losartan, and to novel methods for the production of intermediate compounds which are suitable for the production of losartan. One aspect of the invention is a method for the production of a compound of general formula (I), which can arise as an intermediate step in the inventive representation of losartan.
- -
-
Page/Page column 20; 32-33
(2008/06/13)
-