- Synthesis and reactivity of platinum(II) triphenylphosphino complexes with aromatic aldoximes
-
trans-[Pt(μ-Cl)Cl(PPh3)]2 reacted with arylaldoximes in 1,2-dichloroethane to afford [PtCl2(PPh3){N(OH)[dbnd]CHAr}] (Ar = 3,4-dimethoxyphenyl, 1-naphthyl, 9-anthryl) where aldoxime ligands are N-coordinated to p
- Belli Dell' Amico, Daniela,Colalillo, Marialuigia,Labella, Luca,Marchetti, Fabio,Samaritani, Simona
-
-
Read Online
- Dehydrative Beckmann rearrangement and the following cascade reactions
-
The Beckmann rearrangement has been predominantly studied for the synthesis of amide and lactam. By strategically using the in situ generated Appel's salt or Mitsunobu's zwitterionic adduct as the dehydrating agent, a series of Beckmann rearrangement and following cascade reactions have been developed herein. The protocol allows the conversion of various ketoximes into amide, thioamide, tetrazole and imide products in modular procedures. The generality and tolerance of functionalities of this method have been demonstrated.
- Liu, Yinghui,Wei, Yongjiao,Xie, Lan-Gui
-
supporting information
(2021/11/16)
-
- Copper-Catalyzed Aza-Sonogashira Cross-Coupling To Form Ynimines: Development and Application to the Synthesis of Heterocycles
-
Nitrogen-substituted alkynes, such as ynamines and ynamides, are versatile synthetic building blocks. Ynimines bearing additional nucleophilic and electrophilic centers relative to ynamines and ynamides are expected to have high synthetic potential. However, their chemical reactivity remains unexplored owing mainly to the lack of synthetic accessibility. We report herein a versatile copper-catalyzed synthesis of ynimines from readily available O-acetyl ketoximes and terminal alkynes. A wide range of O-acetyl ketoximes derived from diaryl ketones, aryl alkyl ketones and dialkyl ketones underwent cross-coupling with a diverse set of terminal alkynes to afford the ynimines in good to excellent yields. An unprecedented [5+1] heteroannulation reaction exploiting the reactivity of the ynimine generated in situ was subsequently developed for the synthesis of medicinally important heterocycles, including isoquinolines, azaindoles, azabenzofurans, azabenzothiophenes and carbolines.
- Lavernhe, Rémi,Torres-Ochoa, Rubén O.,Wang, Qian,Zhu, Jieping
-
supporting information
p. 24028 - 24033
(2021/10/07)
-
- Copper-catalyzed synthesis of oxime ethers from iminoxy radical (C[dbnd]N–O[rad]) and maleimides via radical addition
-
An efficient Cu(II)-catalyzed radical addition of maleimides has been achieved. The identified copper catalyst enables the formation of oxime radicals (N–O[rad]) by cleaving the O–H bond in ketoximes, followed by the radical addition to N-substituted male
- Han, Ziwei,Shen, Subo,Zheng, Feng,Hu, Han,Zhang, Jianmin,Zhu, Shizheng
-
supporting information
(2019/09/30)
-
- Rhodium-catalysed synthesis of fused pyrimidine derivatives employing N-sulfonyl-1,2,3-triazoles as a 1-aza-[4C] synthon
-
A new synthetic application of N-sulfonyl-1,2,3-triazoles acting as a 1-aza-[4C] synthon via the 1,2-shift reaction of an α-imine rhodium carbene was developed for the synthesis of fused pyrimidine derivatives. The high reactivity of the strained three-me
- Xu, Ze-Feng,An, Yuehui,Chen, Yidian,Duan, Shengguo
-
supporting information
p. 1849 - 1853
(2019/06/20)
-
- Scope and mechanism of a true organocatalytic beckmann rearrangement with a boronic acid/perfluoropinacol system under ambient conditions
-
Catalytic activation of hydroxyl functionalities is of great interest for the production of pharmaceuticals and commodity chemicals. Here, 2-alkoxycarbonyl- and 2-phenoxycarbonyl-phenylboronic acid were identified as efficient catalysts for the direct and chemoselective activation of oxime N-OH bonds in the Beckmann rearrangement. This classical organic reaction provides a unique approach to prepare functionalized amide products that may be difficult to access using traditional amide coupling between carboxylic acids and amines. Using only 5 mol % of boronic acid catalyst and perfluoropinacol as an additive in a polar solvent mixture, the operationally simple protocol features mild conditions, a broad substrate scope, and a high functional group tolerance. A wide variety of diaryl, aryl-alkyl, heteroaryl-alkyl, and dialkyl oximes react under ambient conditions to afford high yields of amide products. Free alcohols, amides, carboxyesters, and many other functionalities are compatible with the reaction conditions. Investigations of the catalytic cycle revealed a novel boron-induced oxime transesterification providing an acyl oxime intermediate involved in a fully catalytic nonself-propagating Beckmann rearrangement mechanism. The acyl oxime intermediate was prepared independently and was subjected to the reaction conditions. It was found to be self-sufficient; it reacts rapidly, unimolecularly without the need for free oxime. A series of control experiments and 18O labeling studies support a true catalytic pathway involving an ionic transition structure with an active and essential role for the boronyl moiety in both steps of transesterification and rearrangement. According to 11B NMR spectroscopic studies, the additive perfluoropinacol provides a transient, electrophilic boronic ester that is thought to serve as an internal Lewis acid to activate the ortho-carboxyester and accelerate the initial, rate-limiting step of transesterification between the precatalyst and the oxime substrate.
- Mo, Xiaobin,Morgan, Timothy D. R.,Ang, Hwee Ting,Hall, Dennis G.
-
supporting information
p. 5264 - 5271
(2018/04/24)
-
- Dichloroimidazolidinedione-Activated Beckmann Rearrangement of Ketoximes for Accessing Amides and Lactams
-
A novel protocol for the activation of the Beckmann rearrangement utilizing the readily available and economical geminal dichloroimidazolidinediones (DCIDs) on a substoichiometric scale (10 mol %) has been developed. A unique self-propagating mechanism for the substoichiometric dichloroimidazolidinedione-activated transformation was proposed and validated. The substrate scope of the developed protocol has been demonstrated by 23 examples with good to excellent yields (mostly 90-98%) in a short time (mostly 10-30 min), including a substrate for synthesizing the monomer of nylon-12 and a complicated steroidal substrate on a preparative scale. This research not only unveils for the first time the synthetic potential of substoichiometric amounts of dichloroimidazolidinediones in promoting chemical transformation but also offers yet another important illustration of the self-propagating cycle in the context of the Beckmann rearrangement activated by a structurally novel organic promoter.
- Gao, Yu,Liu, Jingjing,Li, Zhenjiang,Guo, Tianfo,Xu, Songquan,Zhu, Hui,Wei, Fulan,Chen, Siming,Gebru, Hailemariam,Guo, Kai
-
p. 2040 - 2049
(2018/02/23)
-
- Kinetic Resolution of 2H-Azirines by Asymmetric Imine Amidation
-
Highly efficient kinetic resolution of 2H-azirines by an asymmetric imine amidation was achieved in the presence of a chiral N,N′-dioxide/ScIIIcomplex, thus providing a promising method to obtain the enantioenriched 2H-azirine derivatives and p
- Hu, Haipeng,Liu, Yangbin,Lin, Lili,Zhang, Yuheng,Liu, Xiaohua,Feng, Xiaoming
-
supporting information
p. 10098 - 10101
(2016/08/16)
-
- Gold-Catalyzed Intermolecular Nitrene Transfer from 2H-Azirines to Ynamides: A Direct Approach to Polysubstituted Pyrroles
-
(Chemical Equation Presented). An effective gold-catalyzed intermolecular nitrene transfer by the reaction of 2H-azirines and ynamides is reported, which provides highly substituted pyrroles in a straightforward manner. This transformation proceeds under mild conditions and gives the polysubstituted pyrroles in good-to-excellent yields. Preliminary results indicate that a nongold carbenoid pathway is preferred for current pyrrole synthesis.
- Zhu, Lei,Yu, Yinghua,Mao, Zhifeng,Huang, Xueliang
-
supporting information
p. 30 - 33
(2015/07/28)
-
- Visible-light-induced formal [3+2] cycloaddition for pyrrole synthesis under metal-free conditions
-
A photocatalytic formal [3+2] cycloaddition of 2H-azirines with alkynes has been achieved under irradiation by visible light in the presence of organic dye photocatalysts. This transformation provides efficient access to highly functionalized pyrroles in good yields and has been applied to the synthesis of drug analogues. A primary trial of photocascade catalysis merging energy transfer and redox neutral reactions was shown to be successful. Photo(chemistry) op: A photocatalytic formal [3+2] cycloaddition of 2H-azirines with alkynes has been established under the irradiation of visible light in the presence of an organic dye. This transformation provides efficient access to highly functionalized pyrroles in good yields and has been applied to the formal synthesis of an inhibitor for HMG-CoA reductase.
- Xuan, Jun,Xia, Xu-Dong,Zeng, Ting-Ting,Feng, Zhu-Jia,Chen, Jia-Rong,Lu, Liang-Qiu,Xiao, Wen-Jing
-
supporting information
p. 5653 - 5656
(2014/06/10)
-
- Synthesis and antibacterial activity of oxime ester derivatives containing 16-isopropyl-5,9-dimethyl tetracyclo [10.2.2.01,10.04,9] hexadec-15-ene-5,14- dicarboxyl group
-
Acrylpimaric acid (16-isopropyl-5,9- dimethyltetracyclo [10. 2. 2. 0 1,10.04,9]hexadec- 15-ene-5,14-dicarboxylic acid) was prepared by rosin through Diels-Alder addition reaction, then a series of oxime ester derivatives containing acrylpimaryl (16-isopropyl-5,9-dimethyltetracyclo [10.2.2.01,10.04,9]hexadec-15-ene-5,14-dicarboxyl) group were synthesized. Their structures were characterized by IR, 1HNMR, MS, and elemental analysis. The antibacterial activity of these newly synthesized oxime ester derivatives against Gram-negative bacteria and Gram-positive bacteria were also investigated. The results indicate that compounds display extensive anti-bacterial activity against Gram-negative bacteria and Gram-positive bacteria. Especially compounds (4c, 4d, 4f, 4h and 4k) exhibit excellent anti-bacterial activity against Escherichia coli (Gram-negative bacteria). Compared with the diameter of inhibition zone is 9.66mm of the standard compound bromogeramine, which the diameter of inhibition zone is 12.17mm, 10.00mm, 10.33mm, 9.67mm and 9.67mm respectively.
- Li, Jian,Rao, Xiaoping,Shang, Shibin,Gao, Yanqing,Song, Binglei
-
experimental part
p. 217 - 222
(2012/04/23)
-
- Unexpected C-C bond cleavage: Synthesis of 1,2,4-oxadiazol-5-ones from amidoximes with pentafluorophenyl or trifluoromethyl anion acting as leaving group
-
An unexpected C-C bond cleavage has been observed on pentafluorobenzoylamidoximes under mild basic conditions. This observation has been exploited to develop a new synthesis of 1,2,4-oxadiazol-5-ones from amidoximes using pentafluorobenzoyl chloride or trifluoroacetic anhydride (TFAA) as a double acylating agent. The pentafluorophenyl anion and the trifluoromethyl anion acted as leaving groups in this transformation.
- Gerfaud, Thibaud,Wei, Hai-Long,Neuville, Luc,Zhu, Jieping
-
supporting information; experimental part
p. 6172 - 6175
(2012/01/03)
-
- An efficient one-pot synthesis of oxime ethers from alcohols using triphenylphosphine/carbon tetrachloride
-
A convenient and efficient one-pot O-alkylation of oximes from alcohols using triphenylphosphine in carbon tetrachloride is described. In this method, treatment of alcohols with a mixture of triphenylphosphine, carbon tetrachloride, oxime, and DBU in the presence of catalytic amounts of tetrabutylammonium iodide in refluxing acetonitrile regioselectively furnishes the corresponding O-alkyl ethers in good yields. This methodology is highly efficient O-alkylation of oximes with various structurally diverse alcohols. Semiempirical quantum-mechanic calculations (AM1) for unsymmetrical oxime ethers, indicated a lower heat of formation for Z-isomers. Georg Thieme Verlag Stuttgart - New York.
- Soltani Rad, Mohammad Navid,Khalafi-Nezhad, Ali,Karimitabar, Fatemeh,Behrouz, Somayeh
-
experimental part
p. 1724 - 1730
(2010/07/08)
-
- A simple and effective glycine-catalysed procedure for the preparation of oximes
-
Ketoximes and aldoximes are expeditiously prepared by the reaction of the corresponding carbonyl compound with hydroxylamine hydrochloride in dimethylformamide, in the presence of a sub-stoichiometric quantity of glycine at room temperature. Mild (non-hydroxylic) conditions, simple workup and high yield characterise the methodology.
- Maheswara, Muchchintala,Siddaiah, Vidavalur,Gopalaiah, Kovuru,Rao, Vallabhaneni Madhava,Rao, Chunduri Venkata
-
p. 362 - 363
(2007/10/03)
-
- 1,2,4-Oxadiazolidin-3,5-diones and 1,3,5-triazin-2,4,6-triones as cytosolic phospholipase A2α inhibitors
-
1,2,4-Oxadiazolidin-3,5-dione and 1,3,5-triazin-2,4,6-trione scaffolds were employed as templates to incorporate the pharmacophore requirements of cytosolic phospholipase A2α substrate mimetics. Inhibitors that are active in both enzyme, and ce
- Gopalsamy, Ariamala,Yang, Hui,Ellingboe, John W.,McKew, John C.,Tam, Steve,Joseph-McCarthy, Diane,Zhang, Wen,Shen, Marina,Clark, James D.
-
p. 2978 - 2981
(2008/09/21)
-
- 1-substituted, 3-carboxylic acid piperidine derivatives
-
The present invention relates to therapeutically active azaheterocyclic compounds, a method of preparing the same and to pharmaceutical compositions comprising the compounds. The novel compounds are useful in treating a central nervous system ailment related to the GABA uptake.
- -
-
-
- The catalytic Friedel-Crafts acylation reaction and the catalytic Beckmann rearrangement promoted by a Gallium(III) or an antimony(V) cationic species
-
The catalytic Friedel-Crafts acylation reaction and the catalytic Beckmann rearrangement are successfully carried out by using the active cationic species dichlorogallium(III) perchlorate and tetrachloroantimonium(V) hexafluoroantimonate(V), respectively, which were generated in situ from appropriate silver, gallium(III) or antimony(V) salts.
- Harada,Ohno,Kobayashi,Mukaiyama
-
p. 1216 - 1220
(2007/10/02)
-