3785-33-9Relevant academic research and scientific papers
Steric-Free Bioorthogonal Labeling of Acetylation Substrates Based on a Fluorine-Thiol Displacement Reaction
Lyu, Zhigang,Zhao, Yue,Buuh, Zakey Yusuf,Gorman, Nicole,Goldman, Aaron R.,Islam, Md Shafiqul,Tang, Hsin-Yao,Wang, Rongsheng E.
supporting information, p. 1341 - 1347 (2021/02/01)
We have developed a novel bioorthogonal reaction that can selectively displace fluorine substitutions alpha to amide bonds. This fluorine-thiol displacement reaction (FTDR) allows for fluorinated cofactors or precursors to be utilized as chemical reporters, hijacking acetyltransferase-mediated acetylation both in vitro and in live cells, which cannot be achieved with azide- or alkyne-based chemical reporters. The fluoroacetamide labels can be further converted to biotin or fluorophore tags using FTDR, enabling the general detection and imaging of acetyl substrates. This strategy may lead to a steric-free labeling platform for substrate proteins, expanding our chemical toolbox for functional annotation of post-translational modifications in a systematic manner.
Visible-Light-Assisted Gold-Catalyzed Fluoroarylation of Allenoates
Feng, Chao,Tang, Hai-Jun,Zhang, Xinggui,Zhang, Yu-Feng
supporting information, p. 5242 - 5247 (2020/02/28)
A strategically novel synthetic method for the fluoroarylation of allenic ester was developed that enables the expedient construction of a host of β-fluoroalkyl-containing cinnamate derivatives. The reaction proceeds through visible-light-promoted gold redox catalysis, occurs smoothly under very mild reaction conditions, accommodates a large variety of functional groups, and more importantly allows the incorporation of fluorine and aryl groups with excellent regio- and stereoselectivity. The concomitant activation mode for both the allene motif and the hydrogen fluoride is key for the success of the reaction.
Cross coupling of sulfonyl radicals with silver-based carbenes: A simple approach to β-carbonyl arylsulfones
Li, Jingjing,Lian, Pengcheng,Wan, Xiaobing,Wang, Hanghang,Zheng, Yonggao
supporting information, p. 2163 - 2169 (2020/03/27)
A coupling reaction between sulfonyl radicals and silver-based carbenes has been well established. This simple radical-carbene coupling (RCC) process provided an efficient approach to a variety of β-carbonyl arylsulfones from sodium arylsulfinates and diazo compounds, and was characterized by wide substrate scope, easy scale-up, simple manipulation, accessible starting materials, and mild reaction conditions.
Zirconocene-catalyzed direct (trans)esterification of acyl acids (esters) and alcohols in a strict 1:1 ratio under solvent-free conditions
Tang, Zhi,Jiang, Qiutao,Peng, Lifen,Xu, Xinhua,Li, Jie,Qiu, Renhua,Au, Chak-Tong
supporting information, p. 5396 - 5402 (2017/11/22)
A highly efficient way for the direct (trans)esterification of acyl acids (esters) and alcohols in a strict 1:1 ratio using a zirconocene complex (1, 1 mol%), a strong Lewis acid of good water tolerance, as a catalyst under solvent-free conditions has been developed. A wide range of acid and alcohol (esters) substrates undergo (trans)esterification to produce carboxylic ester motifs in moderate to good or excellent yields with good functional tolerance, such as that towards C-Br as well as CC and CC bonds. And complex 1 can be recycled six times without showing a significant decline in catalytic efficiency. It was demonstrated that cyclandelate, which is used to treat high blood pressure as well as heart and blood-vessel diseases, can be directly synthesized on a gram scale with 81% yield (6.70 g) using complex 1.
Phosphine-Catalyzed Domino β/γ-Additions of Benzofuranones with Allenoates: A Method for Unsymmetrical 3,3-Disubstituted Benzofuranones
Huang, Zhusheng,Yang, Xiuqin,Yang, Fulai,Lu, Tao,Zhou, Qingfa
supporting information, p. 3524 - 3527 (2017/07/17)
A phosphine-catalyzed domino process of benzofuranones with allenoates has been developed which furnishes highly functionalized unsymmetrical 3,3-disubstituted benzofuranones in synthetically useful yields. The mechanism for the transformation is a tandem β-umpolung/γ-umpolung process.
OXAZOLE AND THIAZOLE DERIVATIVES AND THEIR USES 2
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Page/Page column 47, (2008/12/08)
Compounds of formula (I): wherein A, X, R1, R2, R3, R4, R5, R6 and R8 are as defined in the Specification are useful in the treatment of diseases where enhanced M3 receptor activ
Organic Reducing Agents: Some Radical Chain Reactions of Ketyl and 1,3-Dioxolanyl Radicals with Activated Bromides
Fontana, Francesca,Kolt, Ralph J.,Huang, Youqin,Wayner, Danial D. M.
, p. 4671 - 4676 (2007/10/02)
The radical chain reduction of primary and secondary α-bromo esters by 2-propanol and 2-methyldioxolane has been shown to be a kinetically viable process with average chain lengths of >10 at temperatures between 30 and 60 deg C.For electron-deficient bromides, these simple organic reagents may effectively replace the more commonly used (and more expensive) organosilicon or tin hydrides.Some mechanistic insights have been obtained from a combination of kinetic and thermodynamic measurements.The rate constants for the reaction of the 2-hydroxy-2-propyl and the 2-methyl-1,3-dioxolan-2-yl radicals with a primary bromo ester have been estimated to be 8E3 M-1s-1 and 6E3 M-1s-1, respectively, at 30 deg C in acetonitrile.The electrochemical oxidation potentials of a number of electron-rich radicals derived from hydrogen atom abstraction from alcohols and dioxolanes, determined using photomodulation voltammetry, provide an assessment of the thermochemistry of the putative outer sphere electron-transfer reaction between the radical and the α-bromo ester (the value for 1,3-dioxolane has been redetermined and corrects an erroneous value previously published).From these data, it is shown that the order of reactivity of the organic reducing agents follows the same trend as the oxidation potentials of the corresponding radicals.Rate constants for the outer sphere electron-transfer reduction of the bromo esters by electrochemically generated radical anions were used to establish a Marcus-type relationship between the rate constants and the standard potential of the reducing agent.Comparison of these rate constants with those for the reactions of the electron-rich radicals suggest that the reactions of the methanol- and ethanol-derived radicals do not proceed via outer sphere electron transfer as had been previously suggested but have significant bonding (i.e., atom transfer) character at the transition state.Electron transfer in the reactions of the 2-propanol-, and 2-methyl-1,3-dioxolane-derived radicals cannot be rulled out.Nevertheless, the order of reactivity of the organic reducing agents follows the same trend as the oxidation potentials of the corresponding radicals suggesting that these potentials can be used as a predictive tool for the design of new reagents.
Hard Acid and Soft Nucleophile Systems. Part 11. Har-Soft Affinity Inversion: Dehalogenation of α-Halogeno Ketones with Aluminium Chloride and a Thiol
Fuji, Kaoru,Node, Manabu,Kawabata, Takeo,Fujimoto, Mayumi
, p. 1043 - 1048 (2007/10/02)
α-Halogeno ketones have been dehalogenated with a combination of aluminium chloride and ethanethiol.The mechanism involved in deiodination and debromination differs from that of dechlorination and defluorination.A hard-hard interaction between carbonyl oxygen and aluminium chloride and a soft-soft interaction between iodine or bromine and thiol are the dominant factors for direct deiodination and debromination.In dechlorination and defluorination there is initial formation of the corresponding dithioacetal, whereby hard carbonyl oxygen is replaced by the soft sulphur atom. α-Chloro- and α-fluoro-dithioacetals then undergo dehalogenation to afford vinyl sulphide as a result both of a favourable soft-soft interaction between the sulphur atoms in the dithioacetal entity and thiol, and also a favourable hard-hard interaction between the nucleopilic chlorine or fluorine and aluminium chloride. α-Chloro- and α-fluoro-benzyl benzyl ketones afforded the dehalogenated product with concomitant 1,2-transposition of the carbonyl group.This suggests that there is an indirect path which operates competitively via a 1,2-dithio-olefin from α=halogenodithioacetals to vinyl sulphide.Addition of thiol to vinyl sulphide leads to the final product.A concept of hard-soft affinity inversion is proposed.
