2523-36-6Relevant academic research and scientific papers
PROTEIN-MACROMOLECULE CONJUGATES AND METHODS OF USE THEREOF
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Paragraph 0402; 0403, (2021/04/10)
The present disclosure provides protein-macromolecule conjugates, releasable linkers, and macromolecules, as defined herein. The disclosed conjugates provide unique properties that are based at least upon the properties of linker and number of linker-Macromolecule moieties. Also provided herein are a method of synthesis and use of conjugates in treating diseases and disorders.
Palladium-catalyzed synthesis of fluorenes by intramolecular c(sp 2)-h activation at room temperature
Fujihara, Tetsuaki,Tanji, Yutaka,Tsuji, Yasushi
, p. 805 - 808 (2020/05/19)
The synthesis of fluorenes by intramolecular Pd-catalyzed C(sp 2)-H activation of 2-arylbenzyl chlorides was conducted at room temperature by using commercially available triphenylphosphine and pivalic acid as ligands. The desired reactions proceeded efficiently at room temperature, and various substrates were converted into the corresponding fluorene derivatives in excellent yields.
Phosphite-catalyzed alkoxycarbonylation of aryl diazonium salts
Xu, Jian-Xing,Franke, Robert,Wu, Xiao-Feng
supporting information, p. 6180 - 6182 (2018/09/10)
In this communication, an interesting phosphite-catalyzed alkoxycarbonylation of aryl diazonium salts has been reported. At room temperature and under CO pressure, moderate to good yields of the desired esters can be produced in the absence of bases or an
Palladium-Catalyzed Formal [4 + 1] Annulation via Metal Carbene Migratory Insertion and C(sp2)-H Bond Functionalization
Xu, Shuai,Chen, Ri,Fu, Zihao,Zhou, Qi,Zhang, Yan,Wang, Jianbo
, p. 1993 - 1997 (2017/08/14)
A highly efficient and operationally simple palladium-catalyzed formal [4 + 1] annulation reaction has been developed. The reaction is featured by the formation of two different C-C bonds on a carbenic center. It represents a concise method for the synthesis of a wide range of polycyclic aromatic hydrocarbons (PAHs) and 1H-indenes with easily available (trimethylsilyl)diazomethane as the carbene source. Metal carbene migratory insertion and C(sp2)-H bond activation are proposed as the key steps in this transformation. The reaction further demonstrates the versatility of the carbene-based coupling in combination with various transition-metal-catalyzed transformations.
Highly sensitive iridium(III) complex-based phosphorescent probe for thiophenol detection
Xiong, Li,Yang, Lin,Luo, Shuai,Huang, Yan,Lu, Zhiyun
supporting information, p. 13456 - 13462 (2017/10/17)
A cyclometalated iridium(iii) complex (Ir-DNBS) was designed and synthesized as a high-performance phosphorescent thiophenol probe. Ir-DNBS displays a distinct phosphorescence off-on response toward thiophenol with high selectivity, high sensitivity (detection limit: 2.5 nM) and fast response (10 min). It is noteworthy that the signaling phosphore of Ir-DNBS possesses relatively high photoluminescence quantum efficiency (ΦPL = 0.21) together with relatively long lifetime (τ = 2.07 μs), indicative of its potential in achieving high temporal resolution. Ir-DNBS is also applicable to the detection of thiophenol in actual water samples with high recovery rate. Photophysical and spectral characterization results revealed that the probing mechanism of Ir-DNBS toward thiophenol lies in the thiolate-mediated cleavage reaction, resulting in suppressed photo-induced excited state electron transfer process in the reaction product.
Synthesis of Fluorenes Starting from 2-Iodobiphenyls and CH2Br2 through Palladium-Catalyzed Dual C-C Bond Formation
Shi, Guangfa,Chen, Dushen,Jiang, Hang,Zhang, Yu,Zhang, Yanghui
, p. 2958 - 2961 (2016/07/06)
A facile and efficient approach is developed for the synthesis of fluorene and its derivatives starting from 2-iodobiphenyls and CH2Br2. A range of fluorene derivatives can be synthesized under relatively mild conditions. The reaction proceeds via a tandem palladium-catalyzed dual C-C bond formation sequence through the key dibenzopalladacyclopentadiene intermediates, which are obtained from 2-iodobiphenyls through palladium-catalyzed C-H activation.
Chemical Consequences of the Intramolecular Interaction between a Sulphur Atom and a Methoxycarbonyl Group in Fluorene Systems
Nakanishi, Waro,Kusuyama, Yoshiaki,Ikeda, Yoshitsugu,Oki, Michinori
, p. 799 - 804 (2007/10/02)
The intramolecular interaction between a sulphur atom and a methoxycarbonyl group was found to affect their chemical reactivity.The rates of C-S bond cleavage in methyl-9,9-bis(ethylthio)fluorene-x-carboxylate, where x is 1, 2, or 3, with sodium ethanethiolate show that the rate is minimal, though comparable with the others, when x=1, because of steric effects.In contrast, methyl 9-(ethylthio)fluorene-x-carboxylates, where x=1, 2, or 3, exhibit the maximum rate when x=1.The rates of ester exchange in the presence of toluene-p-sulphonic acid indicate that the reaction is accelerated by the presence of two ethylthio groups at the 9 position of methyl fluorene-1-carboxylate but no significant effect is detected if there is only one ethylthio group.The hydrolysis of the thioketal group in 9,9-bis(ethylthio)fluorene is also accelerated by the presence of a 1-methoxycarbonyl group.The implication of these results are discussed with the use of a model compound.
THE EFFECTS OF THE NEIGHBORING METHOXYCARBONYL GROUP AND SULFUR ATOM(S) IN THE CARBON-SULFUR BOND CLEAVAGE AND THE ESTER EXCHANGE IN FLUORENE SYSTEMS
Nakanishi, Waro,Nakanishi, Hitoshi,Yanagawa, Yuko,Ikeda, Yoshitsugu,Oki, Michinori
, p. 105 - 108 (2007/10/02)
9,9-bis(ethylthio)fluorene (1a) reacted with sodium ethanethiolate in methanol ro give 9-ethylthiofluorene and diethyl disulfide suggesting that a C-S bond cleavage occurs by attack of a nucleophile at sulfur if a leaving group is sufficiently stable.The pseudo-first-order rate constans for the reaction of 1a and methoxycarbonyl-substituted 9-ethylthiofluorenes have suggested that the methoxycarbonyl group at 1-position exerts through space interaction eith sulfur atoms(s).The rate constants for ester exchange in 1-methoxycarbonylfluorene and its derivatives have been discussed on the ground of neighboring sulfur participation.
