1466-88-2Relevant articles and documents
Dual-supramolecular contacts induce extreme Hofmann framework distortion and multi-stepped spin-crossover
Ahmed, Manan,Brand, Helen E. A.,Peterson, Vanessa K.,Clegg, Jack K.,Kepert, Cameron J.,Price, Jason R.,Powell, Benjamin J.,Neville, Suzanne M.
, p. 1434 - 1442 (2021)
An extended nitro-functionalised 1,2,4-triazole ligand has been used to induce considerable lattice distortion in a 2-D Hofmann framework materialviacompeting supramolecular interactions. Single crystal X-ray diffraction analyses on [Fe3(N-cintrz)6(Pd(CN)4)3]·6H2O (N-cintrz: (E)-3-(2-nitrophenyl)acrylaldehyde) reveal a substantial deviation from a regular Hofmann structure, in particular as the intra- and inter-layer contacts are dominated by hydrogen-bonding interactions rather than the typical π-stacking arrays. Also, the 2-D Hofmann layers show an assortment of ligand conformations and local FeIIcoordination environments driven by the optimisation of competing supramolecular contacts. Temperature-dependent magnetic susceptibility measurements reveal a two-step spin crossover (SCO) transition. Variable temperature structural analyses show that the two crystallographically distinct FeIIcentres, which are arranged in stripes (2?:?1 ratio) within each Hofmann layer, undergo a cooperative HS ? HS/LS ? LS (HS = high spin, LS = low spin) transition without periodic spin-state ordering. The mismatch between crystallographic (2?:?1) and spin-state (1?:?1) periodicity at the HS?:?LS step provides key insight into the competition (frustration) between elastic interactions and crystallographically driven order.
1,3-Dipolar cycloaddition reactions of C-(2-nitro)-styryl-N-phenyl nitrone leading to the regiospecific and stereospecific synthesis of new isoxazolidine derivatives
Singal, Kewal Krishan
, p. 3571 - 3577 (1996)
New substituted isoxazolidine derivatives have been synthesized through regiospecific and stereospecific 1,3-dipolar cycloadditions of C-(2-nitro)-styryl-N-phenyl nitrone with reactive dipolarophiles in excellent yields and effects of substituents have been noted.
Sodium bismuthate mediated oxidation of allylic and benzylic alcohols
Banik, Bimal K.,Ghatak, Anjan,Venkatraman,Becker, Frederick F.
, p. 2701 - 2705 (2000)
A simple and readily available oxidation of primary allylic and benzylic alcohols to the corresponding aldehydes is carried out by sodium bismuthate in acetic acid.
Simple and scalable electrochemical synthesis of 2,1-benzisoxazoles and quinoline: N -oxides
Rodrigo, Eduardo,Baunis, Haralds,Suna, Edgars,Waldvogel, Siegfried R.
, p. 12255 - 12258 (2019)
Cathodic reduction of the nitro moiety and subsequent intramolecular cyclization affords different substituted 2,1-benzisoxazoles and quinoline N-oxides. This methodology allows the synthesis of two different types of heterocycles from common simple starting materials, using electrons as a sole reagent for this transformation. The electrolysis can be conducted in a very simple undivided electrolysis cell under constant current conditions. This permits working on a larger scale compared to other electrochemical methodologies and represents a significant advantage.
A useful method for the conversion of olefins to nitro olefins
Reddy, G. Sudhakar,Corey
supporting information, p. 3399 - 3402 (2021/05/10)
Triflyl nitrate is easily generated from tetra-n-butylammonium nitrate in CH2Cl2 solution and serves as an effective nitrating agent for a wide range of unsaturated substrates to form nitro olefins.
Enantiodivergent One-Pot Synthesis of Axially Chiral Biaryls Using Organocatalyst-Mediated Enantioselective Domino Reaction and Central-to-Axial Chirality Conversion
Hayashi, Yujiro,Koshino, Seitaro,Kwon, Eunsang,Monde, Kenji,Taniguchi, Tohru
, p. 15786 - 15794 (2021/10/14)
Enantiodivergent one-pot synthesis of biaryls was developed using a catalytic amount of a single chiral source. A domino organocatalyst-mediated enantioselective Michael reaction and aldol condensation provided centrally chiral dihydronaphthalenes with excellent enantioselectivity, from which an enantiodivergent chirality conversion from central-to-axial chirality was achieved. Both enantiomers of biaryls were obtained with excellent enantioselectivity. All transformations can be conducted in a single reaction vessel. A plausible reaction mechanism for the enantiodivergence is proposed.
Heck Reactions of Acrolein or Enones and Aryl Bromides – Synthesis of 3-Aryl Propenals or Propenones and Consecutive Application in Multicomponent Pyrazole Syntheses
Stephan, Marvin,Panther, Jesco,Wilbert, Fabio,Ozog, Pauline,Müller, Thomas J. J.
supporting information, p. 2086 - 2092 (2020/03/23)
3-(Hetero)aryl propenals or propenones are efficiently prepared by a Heck reaction of (hetero)aryl bromides and acrolein or vinyl ketones using Beller's CataCXium Ptb ligand under Jeffery's and Fu's conditions. The formation of these three-carbon building blocks is embedded into consecutive three- and pseudo-four-component syntheses of 3-(hetero)aryl and 3,5-diarylpyrazoles with a broad substitution pattern in moderate to excellent yield.
Enantioselective Aldol Addition of Acetaldehyde to Aromatic Aldehydes Catalyzed by Proline-Based Carboligases
Biewenga, Lieuwe,Charnock, Simon J.,Guo, Chao,Poelarends, Gerrit J.,Saifuddin, Mohammad,Saravanan, Thangavelu
, p. 2522 - 2527 (2020/03/11)
Aromatic β-hydroxyaldehydes, 1,3-diols, and α,β-unsaturated aldehydes are valuable precursors to biologically active natural products and drug molecules. Herein we report the biocatalytic aldol condensation of acetaldehyde with various aromatic aldehydes to give a number of aromatic α,β-unsaturated aldehydes using a previously engineered variant of 4-oxalocrotonate tautomerase [4-OT(M45T/F50A)] as carboligase. Moreover, an efficient one-pot two-step chemoenzymatic route toward chiral aromatic 1,3-diols has been developed. This one-pot chemoenzymatic strategy successfully combined a highly enantioselective aldol addition step catalyzed by a proline-based carboligase [4-OT(M45T/F50A) or TAUT015] with a chemical reduction step to convert enzymatically prepared aromatic β-hydroxyaldehydes into the corresponding 1,3-diols with high optical purity (e.r. up to >99:1) and in good isolated yield (51-92%). These developed (chemo)enzymatic methodologies offer alternative synthetic choices to prepare a variety of important drug precursors.
Novel Staphyloxanthin Inhibitors with Improved Potency against Multidrug Resistant Staphylococcus aureus
Ni, Shuaishuai,Li, Baoli,Chen, Feifei,Wei, Hanwen,Mao, Fei,Liu, Yifu,Xu, Yixiang,Qiu, Xiaoxi,Li, Xiaokang,Liu, Wenwen,Hu, Linghao,Ling, Dazheng,Wang, Manjiong,Zheng, Xinyu,Zhu, Jin,Lan, Lefu,Li, Jian
supporting information, p. 233 - 237 (2018/03/21)
Diapophytoene desaturase (CrtN) is a potential novel target for intervening in the biosynthesis of the virulence factor staphyloxanthin. In this study, 38 1,4-benzodioxan-derived CrtN inhibitors were designed and synthesized to overwhelm the defects of leading compound 4a. Derivative 47 displayed superior pigment inhibitory activity, better hERG inhibitory properties and water solubility, and significantly sensitized MRSA strains to immune clearance in vitro. Notably, 47 displayed excellent efficacy against pigmented S. aureus Newman, Mu50 (vancomycin-intermediate MRSA, VISA), and NRS271 (linezolid-resistant MRSA, LRSA) comparable to that of linezolid and vancomycin in vivo.
Synthesis method of ferrocenyl pyrimidine polydentate ligand and application thereof in Heck reaction
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Paragraph 0050-0051; 0054-0055; 0061-0064, (2018/03/13)
The invention discloses a synthesis method of a ferrocenyl pyrimidine polydentate ligand and application thereof in Heck reaction. Ferrocene, pyridine-2-formaldehyde and amidine salt are adopted as the raw materials, and by means of the three-step reaction of acetylation, aldol condensation and condensation cyclization, the ferrocenyl pyrimidine polydentate ligand can be synthesized, the synthesis method has the advantages of simple operation, mild conditions and no use of expensive reagents, and is easy for mass preparation. The invention also relates to application of the ligand in palladium catalyzed Heck coupling reaction. The result shows that the ferrocenyl pyrimidine tridentate ligand 6h has good thermal stability and efficient catalytic activity. The coupling reaction can be carried out under the condition adopting water as the solvent, and the substrate has a wide applicable range, and tedious anhydrous and anaerobic operation is unnecessary.
