34914-84-6Relevant academic research and scientific papers
Nickel-catalyzed remote hydrosilylation of unconjugated enones with bulky triphenylsilane
Chen, Xue,Jin, Hongwei,Liu, Yunkui,Wang, Zhen,Zhou, Bingwei,Zhou, Jinyong
supporting information, p. 8021 - 8024 (2021/10/04)
Herein we describe a nickel-catalyzed remote hydrosilylation of unconjugated enones with bulky triphenylsilane. A range ofZ-silyl enol ethers are obtained as major isomers due to the process of nickel triggered alkene isomerization. Notably, some specific
Direct Access to Isotopically Labeled Aliphatic Ketones Mediated by Nickel(I) Activation
Donslund, Aske S.,Pedersen, Simon S.,Gaardbo, Cecilie,Neumann, Karoline T.,Kingston, Lee,Elmore, Charles S.,Skrydstrup, Troels
supporting information, p. 8099 - 8103 (2020/03/16)
An extensive range of functionalized aliphatic ketones with good functional-group tolerance has been prepared by a NiI-promoted coupling of either primary or secondary alkyl iodides with NN2 pincer NiII-acyl complexes. The latter were easily accessed from the corresponding NiII-alkyl complexes with stoichiometric CO. This Ni-mediated carbonylative coupling is adaptable to late-stage carbon isotope labeling, as illustrated by the preparation of isotopically labelled pharmaceuticals. Preliminary investigations suggest the intermediacy of carbon-centered radicals.
Iminyl Radicals by Reductive Cleavage of N-O Bond in Oxime Ether Promoted by SmI2: A Straightforward Synthesis of Five-Membered Cyclic Imines
Huang, Fei,Zhang, Songlin
supporting information, p. 7430 - 7434 (2019/10/11)
A new generation method of N-centered radicals from the reductive cleavage of the N-O bond in oxime ether promoted by SmI2 is reported for the first time. The in-situ-generated N-centered radicals underwent intramolecular cyclization to afford five-membered cyclic imines in two manners: N-centered radical addition and N-centered anion nucleophilic substitution. From a synthetic point of view, an efficient synthetic method of five-membered cyclic imines was developed. A mechanism of the transformation was proposed.
Oximinotrifluoromethylation of unactivated alkenes under ambient conditions
Wang, Na,Wang, Jian,Guo, Yu-Long,Li, Lei,Sun, Yan,Li, Zhuang,Zhang, Hong-Xia,Guo, Zhen,Li, Zhong-Liang,Liu, Xin-Yuan
supporting information, p. 8885 - 8888 (2018/08/17)
An efficient protocol for oximinotrifluoromethylation of unactivated alkenes was developed via trifluoromethyl radical-induced intramolecular remote oximino migration under mild reaction conditions, providing a wide range of β-trifluoromethylated oximes. Other fluoroalkyl radicals were also applicable for this transformation. This method provided access to synthetically challenging medium-sized ring scaffolds and the 6,7,5-fused lactam skeleton.
Enolonium Species—Umpoled Enolates
Arava, Shlomy,Kumar, Jayprakash N.,Maksymenko, Shimon,Iron, Mark A.,Parida, Keshaba N.,Fristrup, Peter,Szpilman, Alex M.
supporting information, p. 2599 - 2603 (2017/02/26)
Enolonium species/iodo(III)enolates of carbonyl compounds have been suggested to be intermediates in a wide variety of hypervalent iodine induced chemical transformations of ketones, including α-C?O, α-C?N, α-C?C, and α-carbon–halide bond formation, but they have never been characterized. We report that these elusive umpoled enolates may be made as discrete species that are stable for several minutes at ?78 °C, and report the first spectroscopic identification of such species. It is shown that enolonium species are direct intermediates in C?O, C?N, C?Cl, and C?C bond forming reactions. Our results open up chemical space for designing a variety of new transformations. We showcase the ability of enolonium species to react with prenyl, crotyl, cinnamyl, and allyl silanes with absolute regioselectivity in up to 92 % yield.
Stereoselection in Intramolecular Diels-Alder Reactions of 2-Cyano-1-azadienes: Indolizidine and Quinolizidine Synthesis
Tay, Gidget C.,Sizemore, Nicholas,Rychnovsky, Scott D.
supporting information, p. 3050 - 3053 (2016/07/13)
Progress toward understanding the scope and diastereoselectivity of intramolecular Diels-Alder reactions using 2-cyano-1-azadienes is described herein. The resulting cyanoenamine products are underutilized intermediates in organic synthesis. Assembly of the Diels-Alder precursors was achieved using an improved imine condensation/oxidative cyanation protocol. By this method, several highly substituted indolizidine and quinolizidine architectures were constructed. Quantum mechanical DFT calculations at the B3LYP/6-31+G(d) level of theory were performed for these cyclizations and provide insights into the origins of the observed diastereoselectivities.
Visible-Light-Mediated Generation of Nitrogen-Centered Radicals: Metal-Free Hydroimination and Iminohydroxylation Cyclization Reactions
Davies, Jacob,Booth, Samuel G.,Essafi, Stephanie,Dryfe, Robert A. W.,Leonori, Daniele
supporting information, p. 14017 - 14021 (2016/01/25)
The formation and use of iminyl radicals in novel and divergent hydroimination and iminohydroxylation cyclization reactions has been accomplished through the design of a new class of reactive O-aryl oximes. Owing to their low reduction potentials, the inexpensive organic dye eosin Y could be used as the photocatalyst of the organocatalytic hydroimination reaction. Furthermore, reaction conditions for a unique iminohydroxylation were identified; visible-light-mediated electron transfer from novel electron donor-acceptor complexes of the oximes and Et3N was proposed as a key step of this process.
Copper-catalyzed cyclization and azidation of γ,δ-unsaturated ketone O-benzoyl oximes
Su, Hailin,Li, Weifei,Xuan, Zhaoli,Yu, Wei
supporting information, p. 64 - 70 (2015/03/04)
An intramolecular imination/azidation sequence has been realized through the tetrakis(acetonitrile)copper(I) hexafluorophophate [Cu(CH3CN)4PF6]-catalyzed reaction of γ,δ-unsaturated ketone O-benzoyl oximes with trimethylsi
Heterocycle synthesis based on allylic alcohol transposition using traceless trapping groups
Xie, Youwei,Floreancig, Paul E.
supporting information, p. 4926 - 4929 (2014/05/20)
Allylic alcohols undergo transposition reactions in the presence of Re 2O7 whereby the equilibrium can be dictated by trapping one isomer with a pendent electrophile. Additional ionization can occur when the trapping group is an aldehyde or ketone, thus leading to cyclic oxocarbenium ion formation. Terminating the process through bimolecular nucleophilic addition into the intermediate provides a versatile method for the synthesis of diverse oxygen-containing heterocycles. Understanding the relative rates of the steps in the sequence leads to the design of reactions which create multiple stereocenters with good to excellent levels of control.
Conversion of Weinreb Amides into Benzene Rings Incorporating the Amide Carbonyl Carbon
Clive, Derrick L. J.,Pham, Mai P.
supporting information; experimental part, p. 1685 - 1690 (2009/07/11)
Esters, acids and acid chlorides can be converted via the intermediacy of their corresponding Weinreb amides into benzene derivatives that incorporate the original carbonyl carbon as part of the benzene ring. The process involves treatment of the derived Weinreb amides with 3-butenylmagnesium bromide and an allylic Grignard reagent, followed by ring-closing metathesis, dehydration and dehydrogenation. The dehydration-dehydrogenation can be done under acidic conditions with a mixture of TsOH·H2O and DDQ or in two steps with SOCl2/pyridine, followed by treatment with DDQ. Application of the method to carbohydrates provides a convenient route to C-5 aryl pyranosides.
