17157-48-1Relevant articles and documents
The Energy Surface for Isomeric (1+) Ions: Further Experimental Evidence
Turecek, Frantisek,McLafferty, F. W.
, p. 608 - 611 (1983)
Mass spectra from collisionally activated dissociation (CAD) of (1+) ions, including isotopically labeled analogs, provide further information on the isomers O(1+)> (a), (b), (c) and (d).Our data generally support the recent conclusions from theory by Radom and coworkers and from experiment by Terlouw, Holmes and coworkers.Most acetyl-containing molecular ions form a ions in high purity only at low energies, consistent with isomerization of higher energy molecular ions to form the more stable enol which dissociates to b.Isomer d, prepared from (ClCH2)2CHOH, undergoes facile hydrogen scrambling, presumably through a degenerate 1,2-hydrogen shift.Theory suggests that c undegoes spontaneous isomerization to a and d; although (1+) ions from BrCH2CHO appear to consist of a and ca.15percent d, the latter are formed without substantial hydrogen scrambling.
Modification of adenine and cytosine derivatives with bromoacetaldehyde
Kayasuga,Hashimoto,Negishi,et al.
, p. 932 - 938 (1980)
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Synthesis of 2-unsubstituted 1,3-selenazoles by cyclization of selenoformamide with α-bromocarbonyl compounds
Below, Harald,Pfeiffer, Wolf-Diethard,Geisler, Karlheinz,Saghyan, Ashot S.,Fischer, Christine,Langer, Peter
, p. 592 - 596 (2015)
2-Unsubstituted 1,3-selenazoles were prepared by cyclization of selenoformamide with α-bromoacetophenones. Parent 1,3-selenazole was prepared by cyclization of selenoformamide with α-bromoacetaldehyde.
Kinetic study of the self-reactions of the BrCH2CH2O2 and BrCH(CH3CH(CH3O2 radicals between 275 and 373 K
Villenave, Eric,Moisan, Sandy,Lesclaux, Robert
, p. 2470 - 2477 (2003)
A conventional flash photolysis technique was used to measure the self-reaction rate constants of the primary BrCH2CH2O2 (2-bromoethylperoxy) and secondary BrCH(CH3)CH(CH3)O2 (2-bromo-l-methylpropylperoxy) β-brominated peroxy radicals, at temperatures in the range of 275-373 K. The absolute UV absorption spectra of BrCH2CH2O2 and BrCH(CH3)CH(CH3)O2 were also measured and compared to those obtained previously for these radicals. The temperature dependence of the self-reaction rate constants provided the following Arrhenius expressions: k(BrCH2CH2O2 + BrCH2CH2O2) = (6.15+5.152.99) × 10-14 exp{(1247 ± 203) K/T} cm3 molecule-1 s-1 and k(BrCH(CH3)CH(CH3)O2 + BrCH(CH3)CH(CH3)O2) = (7.60+22.05-5.65) × 10-15 exp{(1305 ± 428) K/T} cm3 molecule-1 s-1, where the uncertainties represent 95% confidence limits associated with the statistical fitting procedure and include the contribution for the expanded uncertainties in the individual rate constant. These results confirm the enhancement of the peroxy radical self-reaction reactivity upon β-substitution, which is similar for Br, Cl, or OH substituents. Structure-activity relationships are proposed for self-reactions of β-substituted peroxy radicals.
Synthesis of Ketones by C?H Functionalization of Aldehydes with Boronic Acids under Transition-Metal-Free Conditions
Roscales, Silvia,Csáky, Aurelio G.
supporting information, p. 8728 - 8732 (2021/03/16)
A method for the synthesis of ketones from aldehydes and boronic acids via a transition-metal-free C?H functionalization reaction is reported. The method employs nitrosobenzene as a reagent to drive the simultaneous activation of the boronic acid as a boronate and the activation of the C?H bond of the aldehyde as an iminium species that triggers the key C?C bond-forming step via an intramolecular migration from boron to carbon. These findings constitute a practical, scalable, and operationally straightforward method for the synthesis of ketones.
Scaffold-Hopping Strategy on a Series of Proteasome Inhibitors Led to a Preclinical Candidate for the Treatment of Visceral Leishmaniasis
Thomas, Michael,Brand, Stephen,De Rycker, Manu,Zuccotto, Fabio,Lukac, Iva,Dodd, Peter G.,Ko, Eun-Jung,Manthri, Sujatha,McGonagle, Kate,Osuna-Cabello, Maria,Riley, Jennifer,Pont, Caterina,Simeons, Frederick,Stojanovski, Laste,Thomas, John,Thompson, Stephen,Viayna, Elisabet,Fiandor, Jose M.,Martin, Julio,Wyatt, Paul G.,Miles, Timothy J.,Read, Kevin D.,Marco, Maria,Gilbert, Ian H.
supporting information, p. 5905 - 5930 (2021/06/01)
There is an urgent need for new treatments for visceral leishmaniasis (VL), a parasitic infection which impacts heavily large areas of East Africa, Asia, and South America. We previously reported on the discovery of GSK3494245/DDD01305143 (1) as a preclinical candidate for VL and, herein, we report on the medicinal chemistry program that led to its identification. A hit from a phenotypic screen was optimized to give a compound with in vivo efficacy, which was hampered by poor solubility and genotoxicity. The work on the original scaffold failed to lead to developable compounds, so an extensive scaffold-hopping exercise involving medicinal chemistry design, in silico profiling, and subsequent synthesis was utilized, leading to the preclinical candidate. The compound was shown to act via proteasome inhibition, and we report on the modeling of different scaffolds into a cryo-EM structure and the impact this has on our understanding of the series' structure-activity relationships.
Pd-Catalyzed Decarboxylative Olefination: Stereoselective Synthesis of Polysubstituted Butadienes and Macrocyclic P-glycoprotein Inhibitors
Chen, Xiangyang,Hao, Jiping,Houk, K. N.,Li, Yingzi,Lou, Liguang,Quan, Haitian,Song, Bichao,Wang, Lu,Xia, Yuanzhi,Xie, Peipei,Xu, Zhongliang,Yang, Weibo
supporting information, p. 9982 - 9992 (2020/06/27)
The efficient and stereoselective synthesis of polysubstituted butadienes, especially the multifunctional butadienes, represents a great challenge in organic synthesis. Herein, we wish to report a distinctive Pd(0) carbene-initiated decarboxylative olefination approach that enables the direct coupling of diazo esters with vinylethylene carbonates (VECs), vinyl oxazolidinones, or vinyl benzoxazinones to afford alcohol-, amine-, or aniline-containing 1,3-dienes in moderate to high yields and with excellent stereoselectivity. This protocol features operational simplicity, mild reaction conditions, a broad substrate scope, and gram-scalability. Notably, a structurally unique allylic Pd(II) intermediate was isolated and characterized. DFT calculation and control experiments demonstrated that a rare Pd(0) carbene intermediate could be involved in this reaction. Moreover, the polysubstituted butadienes as novel building blocks were unprecedentedly assembled into macrocycles, which efficiently inhibited the P-glycoprotein and dramatically reversed multidrug resistance in cancer cells by 190-fold.