886-66-8Relevant articles and documents
A base-promoted tandem approach to bicyclic 8-membered ring ketones
dos Santos, Emerson E. F.,de Souza, Gabriela F. P.,Simoni, Deborah A.,Salles, Airton G.
, p. 3249 - 3253 (2020)
A base-promoted tandem route toward unprecedented bicyclic 8-membered ring ketones is reported. Under our approach, the targeted products are delivered in high yields from phenylacetylenes and 1,3-diketones. The method has a good scope and gives access to a complex structure that offers a wealth of opportunities for further functionalization.
Enantioselective Decarboxylative α-Alkynylation of β-Ketocarbonyls via a Catalytic α-Imino Radical Intermediate
Wang, Dehong,Zhang, Long,Luo, Sanzhong
, p. 4924 - 4927 (2017)
A distinctive aminocatalysis via α-imino radical is reported on the basis of SET oxidation of a secondary enamine. The combination of chiral primary amine catalysis and visible-light photoredox catalysis enables the enantioselective decarboxylative coupling of propiolic acid and β-ketocarbonyls to afford alkynylation adducts with high enantioselectivity. Mechanism studies indicate the reaction proceeds via an α-imino radical addition.
Selective Carboxylate Directed ortho Functionalization in Copper Catalyzed Reactions of Polyiodo Aromatics: A Straightforward Preparation of 5,7-Diiodo-1H-isochromen-1-ones
Anselmi, Elsa,Bahlaouan, Zineb,Inack Ngi, Samuel,Parrain, Jean Luc,Magnier, Emmanuel,Abarbri, Mohamed
, p. 6131 - 6136 (2017)
A facile, and totally regioselective one-pot approach to synthesize 5,7-diiodo-3-substituted-isocoumarins is described. This reaction was realized by using copper iodide as the catalyst under mild reaction conditions. The methodology was used to design a wide variety of compounds and was tolerant to a large number of functional groups. Interestingly, among the three possible carbon–iodine bonds, only one was reactive, which left the two others intact for further functionalization.
Selective synthesis of 2-aryl-3-alkenylindoles and 2-aryl-3-alkynylindoles by palladium-catalyzed ligand-promoted annulative coupling of anilines and propargyl alcohols
Li, Qiang,Xia, Ying,Yan, Xufei,Zhou, Xiangge,Zhu, Maoshuai
, (2021)
A palladium-catalyzed annulative reaction between aniline and propargyl alcohol has been developed. Propargyl alcohols act as internal or terminal alkynes in the reactions through C?H/C?C activation in the presence of Ac-Gly-OH or Xantphos as ligand, resulting in the formation of 3-alkenylindoles or 3-alkynylindoles respectively. The incorporated alkenyl and alkynyl groups could be engaged for further derivations to form versatile indole skeletons with potential applications.
Unusual Transformations of Highly Unsaturated Trifluoromethanesulfonamide Derivatives
Ushakova,Shainyan
, p. 351 - 353 (2019)
Oxidative condensation of N,N-bis(prop-2-yn-1-yl)trifluoromethanesulfonamide in DMSO involved only one ethynyl group, whereas in aqueous methanol 1,8-bis(trifluoromethanesulfonyl)-1,8-diazacyclotetradeca-3,5,10,12-tetrayne was obtained. N,N′-(Hexa-2,4-diyn-1,6-diyl)bis(trifluoromethanesulfonamide) in hexane solution was unexpectedly converted to diphenyldiacetylene, presumably, as a result of annulation of highly unsaturated carbon chains in the initial polyacetylene molecule and elimination of trifluoromethanesulfonamide and trifluoromethanesulfonamidomethyl residues.
Synthesis and spectroscopic characterization of ?-bonded phenothiazinonepalladium complexes
Konishi, Hisatoshi,Matsumura, Chisato,Okano, Tamon,Kiji, Jitsuo
, p. 245 - 248 (1989)
Treatment of 4-iodo-3H-phenothiazin-3-one with tetrakis(triphenylphosphine)palladium(0) in boiling benzene yields trans-iodo(3H-phenothiazin-3-one-4-yl)bis(triphenylphosphine)palladium(II) by oxidative addition. 5H-Benzo>phenothiazin-5-one-6-yl complex is prepared in a similar manner.The ?-bonded iminoquinone structure of the complexes has been elucidated by 1H, 13C, and 31P NMR spectroscopy.
Cu(OAc)2-catalysed oxidative dual C-H/N-H activation of terminal alkynes and N-deprotected sulfonimidamides: An easy access to N-alkynylated sulfonimidamides
Nandi, Ganesh Chandra,Kota, Sudhakar Rao,Naicker, Tricia,Govender, Thavendran,Kruger, Hendrick G.,Arvidsson, Per I.
, p. 2861 - 2867 (2015)
We report a mild and efficient Cu(OAc)2-catalysed protocol for the oxidative C-N cross-coupling of terminal alkynes and N-deprotected sulfonimidamides. The reaction leads to hitherto unknown N-alkynylated sulfonimidamides. Furthermore, we found that the synthesised N-alkynylated sulfonimidamides could undergo silica-gel-mediated hydrolysis to give the corresponding N-acyl-sulfonimidamides, as well as borane-dimethyl sulfide-mediated reduction to give the corresponding N-alkylated sulfonimidamides.
Aerobic Copper Catalysis for Tandem Oxy-N-alkenylation of [1,2,3]Triazolo[1,5-a]pyridines
Pankajakshan, Sreekumar,Ang, Wei Li,Sreejith, Sivarampanicker,Stuparu, Mihaiela Corina,Loh, Teck-Peng
, p. 3034 - 3038 (2016)
N-Alkenylated triazolinone ylides were generated through copper-catalyzed oxy-N-alkenylation of triazolopyridines. The mechanistic course of this aerobic tandem reaction has been experimentally elucidated and primary photophysical data of the ylide products are also given. (Figure presented.).
Rhodium-catalyzed annulative coupling of: N-aryl-2-aminopyridine and propargylic amine via selective C-C and C-H bond activation
He, Shiyu,Yan, Xufei,Lei, Yanxi,Xiang, Haifeng,Zhou, Xiangge
, p. 2284 - 2287 (2020)
A Rh(iii)-catalyzed/Cu(ii)-mediated cascade reaction between N-aryl-2-aminopyridine and propargylic amine has been developed. Selective C(sp2)-H bond activation and C(sp)-C(sp3) cleavage occurred during the reaction, which was followed by a cyclization reaction to provide an unprecedented synthetic route to form 1,2-disubstituted indoles in yields up to 85%.
CuI-Mediated Bromoalkynylation and Hydroalkynylation Reactions of Unsymmetrical Benzynes: Complementary Modes of Addition
Xiao, Xiao,Wang, Tao,Xu, Feng,Hoye, Thomas R.
, p. 16564 - 16568 (2018)
Benzynes formed by heating a suitable triyne (or tetrayne) substrate are shown to react with in situ generated alkynyl copper species. The latter are compatible with the polyyne substrates and two types of chemistries have been achieved: (i) 1-bromo-1-alkynes efficiently undergo net bromoalkynylation of the (unsymmetrical) benzynes and (ii) in situ generated alkynylcopper species give rise to hydroalkynylation products. The regiochemical preferences of these two modes of reaction are complementary to one another with respect to the position of alkynyl substituent in the final products.
New Palladium – ZrO2 Nano-Architectures from Thermal Transformation of UiO-66-NH2 for Carbonylative Suzuki and Hydrogenation Reactions
Alsalahi, Waleed,Augustyniak, Adam W.,Tylus, W?odzimierz,Trzeciak, Anna M.
supporting information, (2021/12/22)
The new nanocomposites, Pd/C/ZrO2, PdO/ZrO2, and Pd/PdO/ZrO2, were prepared by thermal conversion of Pd@UiO-66-Zr?NH2 (MOF) in nitrogen or air atmosphere. The presence of Pd nanoparticles, uniformly distributed on the ZrO2 or C/ZrO2 matrix, was evidenced by transmission electron microscopy, scanning electron microscopy (SEM), Raman and X-ray Photoelectron Spectroscopy (XPS) methods. All pyrolysed composites retained the shape of the MOF template. They catalyze carbonylative Suzuki coupling under 1 atm CO with an efficiency significantly higher than the original Pd@UiO-66-Zr?NH2. The most active PdO/ZrO2 composite, formed benzophenone with TOF up to 1600 h?1, while by using Pd@UiO-66-Zr?NH2, much lower TOF values, 51–95 h?1, were achieved. After the reaction, PdO/ZrO2 was recovered with the same composition and catalytic activity. Very good results were also obtained in the transfer hydrogenation of benzophenones to alcohols with Pd/C/ZrO2 and PdO/ZrO2 catalysts under microwave irradiation.
Synthesis of 3,4-bis(Butylselanyl)selenophenes and 4-alkoxyselenophenes promoted by oxone
Hellwig, Paola S.,Guedes, Jonatan S.,Barcellos, Angelita M.,Perin, Gelson,Lenard?o, Eder J.
, (2021/05/28)
We describe herein an alternative transition-metal-free procedure to access 3,4-bis(butylsela nyl)selenophenes and the so far unprecedented 3-(butylselanyl)-4-alkoxyselenophenes. The protocol involves the 5-endo-dig electrophilic cyclization of 1,3-diynes promoted by electrophilic organosele-nium species, generated in situ through the oxidative cleavage of the Se-Se bond of dibutyl diselenide using Oxone as a green oxidant. The selective formation of the title products was achieved by controlling the solvent identity and the amount of dibutyl diselenide. By using 4.0 equiv of dibutyl diselenide and acetonitrile as solvent at 80?C, four examples of 3,4-bis(butylselanyl)selenophenes were obtained in moderate to good yields (40–78%). When 3.0 equiv of dibutyl diselenide were used, in the presence of aliphatic alcohols as solvent/nucleophiles under reflux, 10 3-(butylselanyl)-4-alkoxyselenophenes were selectively obtained in low to good yields (15–80%).
Copper-Catalyzed Intermolecular Enantioselective Radical Oxidative C(sp3)?H/C(sp)?H Cross-Coupling with Rationally Designed Oxazoline-Derived N,N,P(O)-Ligands
Gu, Qiang-Shuai,Guo, Kai-Xin,Li, Zhong-Liang,Liu, Lin,Liu, Xin-Yuan,Tian, Yu,Yang, Chang-Jiang,Ye, Liu
supporting information, p. 26710 - 26717 (2021/11/18)
The intermolecular asymmetric radical oxidative C(sp3)?C(sp) cross-coupling of C(sp3)?H bonds with readily available terminal alkynes is a promising method to forge chiral C(sp3)?C(sp) bonds because of the high atom and step economy, but remains underexplored. Here, we report a copper-catalyzed asymmetric C(sp3)?C(sp) cross-coupling of (hetero)benzylic and (cyclic)allylic C?H bonds with terminal alkynes that occurs with high to excellent enantioselectivity. Critical to the success is the rational design of chiral oxazoline-derived N,N,P(O)-ligands that not only tolerate the strong oxidative conditions which are requisite for intermolecular hydrogen atom abstraction (HAA) processes but also induce the challenging enantiocontrol. Direct access to a range of synthetically useful chiral benzylic alkynes and 1,4-enynes, high site-selectivity among similar C(sp3)?H bonds, and facile synthesis of enantioenriched medicinally relevant compounds make this approach very attractive.