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121.
The [3 + 2] cycloaddition reaction between sodium azide and various organic nitriles proceeds smoothly in the presence of amine salts as catalyst in dimethylformamide. The corresponding 5-substituted 1-H tetrazoles were obtained under mild condition in good to excellent yields. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献
122.
Use of the calcium-ethylenediamine and sodium-liquid ammonia reduction systems for the ring opening of dihydropyran derivatives was studied. (Z)-Alkenyl alcohols and (E)-alkenyl alcohols were stereoselectively synthesized respectively. 相似文献
123.
Misa Sugino Keisuke Hatanaka Tetsuya Miyano Ichiro Hisaki Mikiji Miyata Aya Sakon Hidehiro Uekusa Norimitsu Tohnai 《Tetrahedron letters》2014
An organic salt composed 9,10-bis(4-aminophenyl)anthracene and hypophosphorous acid emits yellow-green fluorescence in the crystalline state. The salt also gives water inclusion crystal which provides blue-green fluorescence. Single X-ray crystal studies revealed that water molecules induced the fluorescence change resulting from reaggregation of molecular packing. 相似文献
124.
Cross‐Coupling of Organolithium with Ethers or Aryl Ammonium Salts by C−O or C−N Bond Cleavage
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Ze‐Kun Yang Dong‐Yu Wang Hiroki Minami Hiroyuki Ogawa Takashi Ozaki Dr. Tatsuo Saito Dr. Kazunori Miyamoto Dr. Chao Wang Prof. Dr. Masanobu Uchiyama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(44):15693-15699
Various aryl‐, alkenyl‐, and/or alkyllithium species reacted smoothly with aryl and/or benzyl ethers with cleavage of the inert C?O bond to afford cross‐coupled products, catalyzed by commercially available [Ni(cod)2] (cod=1,5‐cyclooctadiene) catalysts with N‐heterocyclic carbene (NHC) ligands. Furthermore, the coupling reaction between the aryllithium compounds and aryl ammonium salts proceeded under mild conditions with C?N bond cleavage in the presence of a [Pd(PPh3)2Cl2] catalyst. These methods enable selective sequential functionalizations of arenes having both C?N and C?O bonds in one pot. 相似文献
125.
126.
An unusual substitution reaction of an aromatic sulfonic group based on 3-carbonyl-4-phenolsulfonic acid was discovered in a diazo-coupling process.The reaction occurred under mild reaction conditions (pH 8.0-9.0.0-5 C,solvent:water) within a short reaction time(1h).A plausible substitution reaction mechanism by phenol-ketone resonance was proposed. 相似文献
127.
Jean Escudie Claude Couret Henri Ranaivonjatovo Mohamed Lazraq Jacques Satge 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2):27-31
Abstract Two new diphosphenes 7 and 10 have been synthesized by action of DBU on trichlorogermylphosphines 4 and 8; this route involves the intermediate formation of chlorophosphines 5 and 9. Diphosphenes 7 and 10 are stabilized by the 2,6-bis(trifuoromethyl)phenyl group which presents both steric and electronic effects and is used for the first time in phosphorus chemistry. 相似文献
128.
Mari Vellakkaran Taehwan Kim Sungwoo Hong 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2022,134(1):e202113658
The site-selective C?H functionalization of heteroarenes is of considerable importance for streamlining the rapid modification of bioactive molecules. Herein, we report a general strategy for visible-light-induced β-carbonyl alkylation at the C4 position of pyridines with high site selectivity using various cyclopropanols and N-amidopyridinium salts. In this process, hydrogen-atom transfer between the generated sulfonamidyl radicals and O?H bonds of cyclopropanols generates β-carbonyl radicals, providing efficient access to synthetically valuable β-pyridylated (aryl)ketones, aldehydes, and esters with broad functional-group tolerance. In addition, the mild method serves as an effective tool for the site-selective late-stage functionalization of complex and medicinally relevant molecules. 相似文献
129.
A series of Mn(II) aminophosphonate complexes were successfully synthesized and intercalated into the hydroxy double salt [Zn5(OH)8]Cl2·yH2O. Complex incorporation led to an increase in the interlayer spacing from 7.8 to 10–12 Å. Infrared spectroscopy showed the presence of the characteristic vibration peaks of the Mn(II) complexes in the intercalates' spectra, indicating successful incorporation. The complex-loaded composites had somewhat lower proton relaxivities than the pure complexes. Nevertheless, these intercalates may have use as MRI contrast agents for patients with poor kidney function, where traditional Gd(III)-based contrast agents cause severe renal failure. 相似文献
130.
Philip Eckert Prof. Dr. Michael G. Organ 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(69):15751-15754
The impact of LiBr and ZnBr2 salts on the Negishi coupling of alkylZnBr and dialkylzinc nucleophiles with both electron-rich and -poor aryl electrophiles has been examined. Focusing only on the more difficult coupling of deactivated (electron-rich) oxidative addition partners, LiBr promotes coupling with BuZnBr, but does not have such an effect with Bu2Zn. The presence of exogenous ZnBr2 shuts down the coupling of both BuZnBr and Bu2Zn, which has been shown before with alkyl electrophiles. Strikingly, the addition of LiBr to Bu2Zn reactions containing exogenous ZnBr2 now fully restores coupling to levels seen without any salt present. This suggests that there is a very important interaction between LiBr and ZnBr2. It is proposed that Lewis acid adducts are forming between ZnBr2 and the electron-rich Pd0 centre and the bromide from LiBr forms inorganic zincates that prevent the catalyst from binding to ZnBr2. This idea has been supported by catalyst design as chlorinating the backbone of the NHC ring of Pd-PEPPSI-IPent to produce Pd-PEPPSI-IPentCl catalyst now gives quantitative conversion, up from a ceiling of only 50 % with the former catalyst. 相似文献