1198-34-1Relevant articles and documents
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Bunnett,J.F.,Sundberg,J.E.
, p. 1702 - 1706 (1976)
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Fluorotetraphenylbismuth: A new reagent for efficient regioselective α-phenylation of carbonyl compounds
Ooi, Takashi,Goto, Ryoji,Maruoka, Keiji
, p. 10494 - 10495 (2003)
Synthesis and X-ray crystallographic characterization of fluorotetraphenylbismuth (1) has been achieved for the first time, revealing that the bismuth center of 1 adopts a distorted trigonal bipyramidal geometry with three ipso carbons at the equatorial sites and one ipso carbon and fluorine atom at the apical sites. Contrary to the previous common understanding of this type of organobismuth(V) compound, 1 was found to be thermally stable, maintaining its amphiphilic property. Hence, 1 can be used as an off-the-shelf reagent in organic synthesis, and its utility has been clearly demonstrated in applications to the efficient α-phenylation of ketones and esters. For instance, simple mixing of 1 and 1-trimethylsiloxy-3,4-dihydronaphthalene in THF at -40 °C and stirring at room temperature for 10 min gave rise to 2-phenyl-1-tetralone almost quantitatively without formation of the polyphenylated products. In addition to the generality of this method, applicability of our approach to the selective α-alkenylation of carbonyl compounds was also demonstrated by the use of fluoro(2-phenylethenyl)tris(p-tolyl)bismuth (2) as a representative reagent. These results imply the vast potential of organobismuth(V) compounds of type 1 and 2 as useful precursors of a wide variety of pentavalent organobismuth compounds based on the utilization of the eminent fluorine-silicon interaction or the inherent basicity of the fluorine atom. Copyright
Deciphering Reactivity and Selectivity Patterns in Aliphatic C-H Bond Oxygenation of Cyclopentane and Cyclohexane Derivatives
Martin, Teo,Galeotti, Marco,Salamone, Michela,Liu, Fengjiao,Yu, Yanmin,Duan, Meng,Houk,Bietti, Massimo
supporting information, p. 9925 - 9937 (2021/06/30)
A kinetic, product, and computational study on the reactions of the cumyloxyl radical with monosubstituted cyclopentanes and cyclohexanes has been carried out. HAT rates, site-selectivities for C-H bond oxidation, and DFT computations provide quantitative information and theoretical models to explain the observed patterns. Cyclopentanes functionalize predominantly at C-1, and tertiary C-H bond activation barriers decrease on going from methyl- and tert-butylcyclopentane to phenylcyclopentane, in line with the computed C-H BDEs. With cyclohexanes, the relative importance of HAT from C-1 decreases on going from methyl- and phenylcyclohexane to ethyl-, isopropyl-, and tert-butylcyclohexane. Deactivation is also observed at C-2 with site-selectivity that progressively shifts to C-3 and C-4 with increasing substituent steric bulk. The site-selectivities observed in the corresponding oxidations promoted by ethyl(trifluoromethyl)dioxirane support this mechanistic picture. Comparison of these results with those obtained previously for C-H bond azidation and functionalizations promoted by the PINO radical of phenyl and tert-butylcyclohexane, together with new calculations, provides a mechanistic framework for understanding C-H bond functionalization of cycloalkanes. The nature of the HAT reagent, C-H bond strengths, and torsional effects are important determinants of site-selectivity, with the latter effects that play a major role in the reactions of oxygen-centered HAT reagents with monosubstituted cyclohexanes.
Identification and Preclinical Evaluation of the Bicyclic Pyrimidine γ-Secretase Modulator BMS-932481
Boy, Kenneth M.,Guernon, Jason M.,Zuev, Dmitry S.,Xu, Li,Zhang, Yunhui,Shi, Jianliang,Marcin, Lawrence R.,Higgins, Mendi A.,Wu, Yong-Jin,Krishnananthan, Subramaniam,Li, Jianqing,Trehan, Ashok,Smith, Daniel,Toyn, Jeremy H.,Meredith, Jere E.,Burton, Catherine R.,Kimura, S. Roy,Zvyaga, Tatyana,Zhuo, Xiaoliang,Lentz, Kimberley A.,Grace, James E.,Denton, Rex,Morrison, John S.,Mathur, Arvind,Albright, Charles F.,Ahlijanian, Michael K.,Olson, Richard E.,Thompson, Lorin A.,Macor, John E.
supporting information, p. 312 - 317 (2019/03/08)
A triazine hit identified from a screen of the BMS compound collection was optimized for potency, in vivo activity, and off-target profile to produce the bicyclic pyrimidine γ-secretase modulator BMS-932481. The compound showed robust reductions of Aβsub
Enantioselective Radical Ring-Opening Cyanation of Oxime Esters by Dual Photoredox and Copper Catalysis
Chen, Jun,Wang, Peng-Zi,Lu, Bin,Liang, Dong,Yu, Xiao-Ye,Xiao, Wen-Jing,Chen, Jia-Rong
supporting information, p. 9763 - 9768 (2019/11/29)
Catalytic enantioselective chemical reactions involving highly reactive radical species remain largely unexplored. We report herein for the first time a novel enantioselective radical ring-opening cyanation of redox-active oxime esters by dual photoreodox
