6952-89-2Relevant articles and documents
Silylium-Ion-Promoted (5+1) Cycloaddition of Aryl-Substituted Vinylcyclopropanes and Hydrosilanes Involving Aryl Migration
Bonetti, Vittorio,He, Tao,Klare, Hendrik F. T.,Oestreich, Martin,Wang, Guoqiang
supporting information, p. 12186 - 12191 (2020/05/22)
A transition-metal-free (5+1) cycloaddition of aryl-substituted vinylcyclopropanes (VCPs) and hydrosilanes to afford silacyclohexanes is reported. Catalytic amounts of the trityl cation initiate the reaction by hydride abstraction from the hydrosilane, and further progress of the reaction is maintained by self-regeneration of the silylium ions. The new reaction involves a [1,2] migration of an aryl group, eventually furnishing 4- rather than 3-aryl-substituted silacyclohexane derivatives as major products. Various control experiments and quantum-chemical calculations support a mechanistic picture where a silylium ion intramolecularly stabilized by a cyclopropane ring can either undergo a kinetically favored concerted [1,2] aryl migration/ring expansion or engage in a cyclopropane-to-cyclopropane rearrangement.
B(C6F5)3-Catalyzed Hydrosilylation of Vinylcyclopropanes
He, Tao,Long, Peng-Wei,Oestreich, Martin
supporting information, p. 7383 - 7386 (2020/10/12)
A hydrosilylation of vinylcyclopropanes (VCPs) catalyzed by the strong boron Lewis acid B(C6F5)3 is reported. For the majority of VCPs, little or no ring opening of the cyclopropyl unit is observed. Conversely, for VCPs with bulky R groups, such as ortho-substituted aryl rings or branched alkyl residues, ring opening is the exclusive reaction pathway. This finding is explained by the thwarted hydride delivery to a sterically shielded, β-silicon-stabilized cyclopropylcarbinyl cation intermediate.
NOVEL APOPTOSIS SIGNAL-REGULATING KINASE 1 INHIBITORS
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Page/Page column 55, (2021/01/23)
The present invention relates to inhibitors of apoptosis signal-regulating kinase 1 ("ASK1"), a process for synthesis of the compounds of the present invention, composition comprising the compounds and use of the compounds for inhibition of ASK1.
Br?nsted acid mediated intramolecular cyclopropane ring expansion/[4 + 2]-cycloaddition
Li, Jian,Zhu, Shangrong,Xu, Qiuneng,Liu, Li,Yan, Shenghu
, p. 10004 - 10008 (2019/12/23)
A cascade reaction of 3-hydroxy-2-phenylisoindolin-1-one and cyclopropyl ketone has been developed via a Br?nsted acid-promoted ring-opening/intramolecular cross-cycloaddition/[4 + 2]-cycloaddition process. The developed methodology provides straightforward access to pentacyclic isoindolin-1-one derivatives under simple reaction conditions.
Mild Ring Contractions of Cyclobutanols to Cyclopropyl Ketones via Hypervalent Iodine Oxidation
Sun, Yan,Huang, Xin,Li, Xiaojin,Luo, Fan,Zhang, Lei,Chen, Mengyuan,Zheng, Shiya,Peng, Bo
supporting information, p. 1082 - 1087 (2018/01/27)
An iodine-mediated oxidative ring contraction of cyclobutanols has been developed. The reaction allows the synthesis of a wide range of aryl cyclopropyl ketones under mild and eco-friendly conditions. A variety of functional groups including aromatic or alkyl halides, ethers, esters, ketones, alkenes, and even aldehydes are nicely tolerated in the reaction. This is in contrast with traditional synthetic approaches for which poor functional group tolerance is often a problem. The practicality of the method is also highlighted by the tunability of iodine oxidation system. Specifically, combining the iodine(III) reagent with an appropriate base allows the reaction to accommodate a range of challenging electron-rich arene substrates. The facile scalability of this reaction is also exhibited herein. (Figure presented.).
Synthesis and methemoglobinemia-inducing properties of analogues of para-aminopropiophenone designed as humane rodenticides
Rennison, David,Conole, Daniel,Tingle, Malcolm D.,Yang, Junpeng,Eason, Charles T.,Brimble, Margaret A.
supporting information, p. 6629 - 6635 (2014/01/06)
A number of structural analogues of the known toxicant para- aminopropiophenone (PAPP) have been prepared and evaluated for their capacity to induce methemoglobinemia - with a view to their possible application as humane pest control agents. It was found that an optimal lipophilicity for the formation of methemoglobin (metHb) in vitro existed for alkyl analogues of PAPP (aminophenones 1-20; compound 6 metHb% = 74.1 ± 2). Besides lipophilicity, this structural sub-class suggested there were certain structural requirements for activity, with both branched (10-16) and cyclic (17-20) alkyl analogues exhibiting inferior in vitro metHb induction. Of the four candidates (compounds 4, 6, 13 and 23) evaluated in vivo, 4 exhibited the greatest toxicity. In parallel, aminophenone bioisosteres, including oximes 30-32, sulfoxide 33, sulfone 34 and sulfonamides 35-36, were found to be inferior metHb inducers to lead ketone 4. Closer examination of Hammett substituent constants suggests that a particular combination of the field and resonance parameters may be significant with respect to the redox mechanisms behind PAPPs metHb toxicity.
