10557-77-4Relevant academic research and scientific papers
Skeletal rearrangement of O-propargylic formaldoximes by a gold-catalyzed cyclization/intermolecular methylene transfer sequence
Nakamura, Itaru,Gima, Shinya,Kudo, Yu,Terada, Masahiro
, p. 7154 - 7157 (2015)
Abstract Skeletal rearrangement of O-propargylic formaldoximes, in the presence of gold catalysts, afforded 4-methylene-2-isoxazolines in good to excellent yields by an intermolecular methylene transfer. In addition, the cascade reaction with maleimide in
Suzuki-Miyaura cross-coupling of 3,4-disubstituted 5-bromoisoxazoles: An efficient access to trisubstituted isoxazoles
Morita, Taiki,Nakamura, Hiroyuki,Tsuda, Masato
, (2021/06/07)
The Suzuki-Miyaura cross-coupling of 3,4-disubstituted 5-bromoisoxazoles 1 at the C5 position has successfully proceeded in the presence of Pd2(dba)3 and P(t-Bu)3·HBF4 catalysts to give the corresponding trisubstituted isoxazoles 3 in good to high yields while suppressing the formation of ketone 4 as a byproduct. The use of bulky phosphine ligand P(t-Bu)3·HBF4 is essential for the current transformation, and the formation of ketone 4, which was a major product in the previous report, was able to be suppressed under the current conditions.
Unusual Reactivity of 4-Vinyl Isoxazoles in the Copper-Mediated Synthesis of Pyridines, Employing DMSO as a One-Carbon Surrogate
Kumar, Pravin,Kapur, Manmohan
supporting information, p. 5855 - 5860 (2020/07/30)
An efficient protocol for the synthesis of nicotinate derivatives and tetrasubstituted pyridines through a copper-mediated cleavage of isoxazoles has been developed. The highlight of the work is the observation of an unusual reactivity of 4-vinyl isoxazoles under the reaction conditions. DMSO serves as a one-carbon surrogate generating an active methylene group during the reaction to form two C-C bonds. This protocol provides a facile and an expeditious approach for the assembly of densely substituted N-heterocyclic compounds.
One-pot synthesis of isoxazoles from enaminones: An application of Fe(II) as the catalyst for ring expansion of 2H-azirine intermediates
Zheng, Yunhui,Yang, Chao,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
, p. 6157 - 6160 (2013/10/22)
We report an application of FeCl2 as an inexpensive, nontoxic, and efficient catalyst in a clean ring expansion reaction of 2H-azirine derivatives, an intermediate formed through the PhI(OAc)2-mediated azirination of readily availabl
Palladium-catalyzed carbonylative α-arylation for accessing 1,3-diketones
Gogsig, Thomas M.,Taaning, Rolf H.,Lindhardt, Anders T.,Skrydstrup, Troels
supporting information; experimental part, p. 798 - 801 (2012/03/09)
With a hint of CO: The first Pd-catalyzed carbonylative α-arylations of simple ketones with carbon monoxide is presented for the direct synthesis of 1,3-diketones (see scheme). The method uses only stoichiometric amounts of CO, and hence allows for the si
Efficient and convenient method for the synthesis of isoxazoles in ionic liquid
Valizadeh, Hassan,Amiri, Mohammad,Gholipur, Hamid
experimental part, p. 108 - 110 (2009/05/07)
An efficient one-pot synthesis of 3,5-disubstitueted isoxazoles from β-diketones in room temperature ionic liquids (ILs) is described. Compared with the classical reaction conditions, this new synthetic method is environmentally friendly and has the advan
Formation of α-hydroxy-β-diketones through hydroxylation of isoxazolium salts: Stereoselective approach to angular cis-diols in polycyclic systems
Takikawa, Hiroshi,Takada, Akiomi,Hikita, Katsuyoshi,Suzuki, Keisuke
supporting information; experimental part, p. 7446 - 7449 (2009/03/12)
Only two steps were needed for the unprecedented oxidation of isoxazoles, which is exploited in the stereocontrolled introduction of an "angular cis-diol" characteristic of polyketide-derived polycyclic natural products, suchas 3. In this two-step process, 1) N-methylation of isoxazole 1 and 2) stereoselective epoxidation of isoxazolium salt 2 withsodium hypochlorite followed by hydrolysis are carried out (Bn: benzyl). (Chemical Equation Presented)
Halogenation of Vinyl Ketoximes. Synthesis of Isoxazoles and Preparation and Silver Ion-Promoted Reactions of 4-Halo-2-isoxazolines
Hansen, John F.,Kim, Yong In,McCrotty, Stephen E.,Strong, Scott A.,Zimmer, Douglas E.
, p. 475 - 479 (2007/10/02)
Reaction of several α,β-unsaturated ketoximes with N-bromosuccinimide (NBS) gave isoxazoles, but yields were lower and the reaction less general than a similar transformation using iodine under basic conditions.With β,β-disubstituted oximes, 4-halo-5,5-disubstituted-2-isoxazolines were obtained using NBS, iodine, or N-chlorosuccinimide.Treatment of the 4-bromoisoxazolines with silver acetate or silver nitrate caused either elimination with rearrangement to give isoxazoles or substitution at C-4, depending upon the nature of the substituents at C-5.
