40217-17-2Relevant academic research and scientific papers
Room Temperature Cu-Catalyzed N-Arylation of Oxazolidinones and Amides with (Hetero)Aryl Iodides
Bhunia, Subhajit,De, Subhadip,Ma, Dawei
supporting information, (2022/02/09)
N,N′-Bis(pyridin-2-ylmethyl)oxalamide (BPMO) was found to be an apposite promoter for the Cu-catalyzed N-arylation of oxazolidinones and primary and secondary amides with (hetero)aryl iodides at room temperature. Excellent chemoselectivity reached between
Atomically Dispersed High-Density Al–N4 Sites in Porous Carbon for Efficient Photodriven CO2 Cycloaddition
Yang, Qihao,Peng, Huaitao,Zhang, Qiuju,Qian, Xu,Chen, Xu,Tang, Xuan,Dai, Sheng,Zhao, Jiajun,Jiang, Kun,Yang, Qiu,Sun, Jian,Zhang, Linjuan,Zhang, Nian,Gao, Honglin,Lu, Zhiyi,Chen, Liang
, (2021/09/20)
Highly active catalysts that can directly utilize renewable energy (e.g., solar energy) are desirable for CO2 value-added processes. Herein, aiming at improving the efficiency of photodriven CO2 cycloaddition reactions, a catalyst composed of porous carbon nanosheets enriched with a high loading of atomically dispersed Al atoms (≈14.4?wt%, corresponding to an atomic percent of ≈7.3%) coordinated with N (AlN4 motif, Al–N–C catalyst) via a versatile molecule-confined pyrolysis strategy is reported. The performance of the Al–N–C catalyst for catalytic CO2 cycloaddition under light irradiation (≈95% conversion, reaction rate = 3.52 mmol g?1 h?1) is significantly superior to that obtained under a thermal environment (≈57% conversion, reaction rate = 2.11 mmol g?1 h?1). Besides the efficient photothermal conversion induced by the carbon matrix, both experimental and theoretical analysis reveal that light irradiation favors the photogenerated electron transfer from the semiconductive Al–N–C catalyst to the epoxide reactant, facilitating the formation of a ring-opened intermediate through the rate-limiting step. This study not only provides an advanced Al–N–C catalyst for photodriven CO2 cycloaddition, but also furnishes new insight for the rational design of superior photocatalysts for diverse heterogeneous catalytic reactions in the future.
Towards the Sarpagine-Ajmaline-Macroline Family of Indole Alkaloids: Enantioselective Synthesis of an N-Demethyl Alstolactone Diastereomer
Dagoneau, Dylan,Wang, Qian,Zhu, Jieping
supporting information, p. 4866 - 4873 (2020/04/15)
the strategy involving the use of functionalized tetrahydro-6H-cycloocta[b]indol-6-one is reported as a key intermediate for synthesis of members of the sarpagine-ajmaline-macroline family of monoterpene indole alkaloids. The desired tricycle was synthesized through the following key steps: 1) Evans’ syn-selective aldolization; 2) Liebeskind–Srogl cross-coupling using the phenylthiol ester of 3-chloropropanoic acid as a surrogate of acrylic thioester for the synthesis of 2,3-disubstituted indoles; and 3) ring-closing metathesis (RCM) for the formation of the eight-membered ring. An N-allylation followed by intramolecular 1,4-addition was planned for synthesis of the vobasine class of natural products. However, attempted cyclizations under a diverse set of conditions involving anionic, radical, and organopalladium/organonickel species failed to produce the bridged ring system. On the other hand, esterification of the pendant primary alcohol function with acetoacetic acid, followed by intramolecular Michael addition, afforded the desired tetracycle with excellent diastereoselectivity. Subsequent functional group manipulation and transannular cyclization of the amino alcohol afforded the N(1)-demethyl-3,5-diepi-alstolactone. We believe that the same synthetic route would afford the alstolactone should the amino alcohol with appropriate stereochemistry be used as the starting material.
Auxiliary-controlled diastereoselective synthesis of a syn C-6-epimer of the ADAM 10 inhibitor GI254023X
Nair, Shankari,Zeevaart, Jan Rijn,Hunter, Roger
, p. 90 - 102 (2020/10/08)
ADAM10 is a cell surface-expressed metalloprotease involved in various cell adhesion and proteolytic processes, in which biological studies have linked an over-expression of ADAM10 to the development and progression of various types of diseases including cancer. GI254023X is a hydroxamate metalloprotease inhibitor known for ADAM10 activity inhibition, but for which structure-activity based biological information for assessing anti-tumour and anti-inflammatory activity is lacking. In this work, an Evans’ asymmetric boron aldol reaction was used to synthesise a syn C-6-epimer of GI254023X intended for biological evaluation against the natural inhibitor.
One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: Theoretical evidence for an asynchronous concerted pathway
Demir, Esra,Sari, Ozlem,?etinkaya, Yasin,Atmaca, Ufuk,Erdem, Safiye Sa?,?elik, Murat
, p. 1805 - 1819 (2020/11/07)
The one-pot reaction of chlorosulfonyl isocyanate (CSI) with epoxides having phenyl, benzyl and fused cyclic alkyl groups in different solvents under mild reaction conditions without additives and catalysts was studied. Oxazolidinones and five-membered cyclic carbonates were obtained in ratios close to 1:1 in the cyclization reactions. The best yields of these compounds were obtained in dichloromethane (DCM). Together with 16 known compounds, two novel oxazolidinone derivatives and two novel cyclic carbonates were synthesized with an efficient and straightforward method. Compared to the existing methods, the synthetic approach presented here provides the following distinct advantageous: being a one-pot reaction with metal-free reagent, having shorter reaction times, good yields and a very simple purification method. Moreover, using the density functional theory (DFT) method at the M06-2X/6-31+G(d,p) level of theory the mechanism of the cycloaddition reactions has been elucidated. The further investigation of the potential energy surfaces associated with two possible channels leading to oxazolidinones and five-membered cyclic carbonates disclosed that the cycloaddition reaction proceeds via an asynchronous concerted mechanism in gas phase and in DCM.
Novel chiral stationary phases based on 3,5-dimethyl phenylcarbamoylated β-cyclodextrin combining cinchona alkaloid moiety
Zhu, Lunan,Zhu, Junchen,Sun, Xiaotong,Wu, Yaling,Wang, Huiying,Cheng, Lingping,Shen, Jiawei,Ke, Yanxiong
, p. 1080 - 1090 (2020/05/25)
Novel chiral selectors based on 3,5-dimethyl phenylcarbamoylated β-cyclodextrin connecting quinine (QN) or quinidine (QD) moiety were synthesized and immobilized on silica gel. Their chromatographic performances were investigated by comparing to the 3,5-dimethyl phenylcarbamoylated β-cyclodextrin (β-CD) chiral stationary phase (CSP) and 9-O-(tert-butylcarbamoyl)-QN-based CSP (QN-AX). Fmoc-protected amino acids, chiral drug cloprostenol (which has been successfully employed in veterinary medicine), and neutral chiral analytes were evaluated on CSPs, and the results showed that the novel CSPs characterized as both enantioseparation capabilities of CD-based CSP and QN/QD-based CSPs have broader application range than β-CD-based CSP or QN/QD-based CSPs. It was found that QN/QD moieties play a dominant role in the overall enantioseparation process of Fmoc-amino acids accompanied by the synergistic effect of β-CD moiety, which lead to the different enantioseparation of β-CD-QN-based CSP and β-CD-QD-based CSP. Furthermore, new CSPs retain extraordinary enantioseparation of cyclodextrin-based CSP for some neutral analytes on normal phase and even exhibit better enantioseparation than the corresponding β-CD-based CSP for certain samples.
Concise and Additive-Free Click Reactions between Amines and CF3SO3CF3
Song, Hai-Xia,Han, Zhou-Zhou,Zhang, Cheng-Pan
supporting information, p. 10907 - 10912 (2019/08/02)
Trifluoromethyl trifluoromethanesulfonate has proved to be an excellent reservoir of difluorophosgene and a promising click ligation for amines in the preparation of urea derivatives, heterocycles, and carbamoyl fluorides under metal- and additive-free conditions. The reactions are rapid, efficient, selective, and versatile, and can be performed in benign solvents, giving products in excellent yields with minimal efforts for purification. The characteristics of the reactions meet the requirements of a click reaction. The use of trifluoromethyl trifluoromethanesulfonate as a click reagent is advantageous over other “CO” sources (e.g., TsOCF3, PhCO2CF3, CsOCF3, AgOCF3, and triphosgene) because this reagent is readily accessible; easy to scale up; and highly reactive, even under metal- and additive-free conditions. It is anticipated that CF3SO3CF3 will be increasingly as important as SO2F2 as a click agent in future drug design and development.
Synthesis of a diastereomer of the marine macrolide lytophilippine A
Klüppel, André,Gille, Annika,Karayel, Ceren Ester,Hiersemann, Martin
supporting information, p. 2421 - 2425 (2019/03/29)
The synthesis of a diastereomer of lytophilippine A required 22 longest linear steps using known building blocks. Cross-metathesis/asymmetric aldol addition and regioselective esterification/ring-closing metathesis served as efficient combi tools for scaffold construction. Detailed NMR investigations in different solvent (systems) provide evidence for a deep-seated configurational misassignment of the molecule named lytophilippine A.
Access towards enantiopure α,α-difluoromethyl alcohols by means of sulfoxides as traceless chiral auxiliaries
Batisse, Chloé,Panossian, Armen,Hanquet, Gilles,Leroux, Frédéric R.
supporting information, p. 10423 - 10426 (2018/09/21)
A new methodology to access enantiopure α,α-difluoromethyl alcohols is hereby being described. The strategy relies on the use of an enantiopure aryl α,α-difluoromethyl sulfoxide employed as chiral and removable auxiliary for the stereoselective difluoromethylation of carbonyl derivatives. The obtained α,α-difluoro-β-hydroxysulfoxides displayed unprecedented diastereomeric ratios.
Synthesis of new C3 symmetric amino acid- and aminoalcohol-containing chiral stationary phases and application to HPLC enantioseparations
Yu, Jeongjae,Armstrong, Daniel W.,Ryoo, Jae Jeong
, p. 74 - 84 (2017/12/26)
We recently reported a new C3-symmetric (R)-phenylglycinol N-1,3,5-benzenetricarboxylic acid-derived chiral high-performance liquid chromatography (HPLC) stationary phase (CSP 1) that demonstrated better results as compared to a previously described N-3,5-dintrobenzoyl (DNB) (R)-phenylglycinol-derived CSP. Over a decade ago, (S)-leucinol, (R)-phenylglycine, and (S)-leucine derivatives were used as the starting materials of 3,5-DNB-based Pirkle-type CSPs for chiral separation. In this study, three new C3-symmetric CSPs (CSP 2, 3, and 4) were prepared by combining the ideas and results mentioned above. Here we describe the synthetic procedures and applications of the new C3-symmetric CSPs (CSP 2–CSP 4).
