An expeditious and effective method for synthesis of isoxazoline from aldoximes and activated alkenes using cetyltrimethylammonium cerium nitrate at room temperature is described.Reaction was completed within short ti...An expeditious and effective method for synthesis of isoxazoline from aldoximes and activated alkenes using cetyltrimethylammonium cerium nitrate at room temperature is described.Reaction was completed within short time period in high yields at room temperature.展开更多
A mild deselenenylation reaction protocol for the preparation of 3, 5-disubstituted isoxazolines and their further application to 3-methyl-5-substituted isoxazoles both in solution phase and solid phase was reported.
An efficient and rapid parallel liquid-phase synthesis of isoxazolines has been reported. The one-pot three-component reaction of polyethylene glycol-supported acrylates, aldehydes and hydroxylamine hydrochloride in...An efficient and rapid parallel liquid-phase synthesis of isoxazolines has been reported. The one-pot three-component reaction of polyethylene glycol-supported acrylates, aldehydes and hydroxylamine hydrochloride in the presence of chloramine-T in methanol gave the corresponding PEG-supported isoxazolines, which can be cleaved from the support under mild condition to afford isoxazolines in good yields (>80%) and high purities (>86%).展开更多
A mild, regioselective 1, 3-dipolar cycloaddition protocol for the preparation of phenylselenomethyl isoxazolines through substituted allyl phenyl selenides and nitrile oxides was reported.
Additions of diethyl phosphite to α-nitroalkenes followed by the introduction of trimethylchlorosilane and an activated alkene, gave the corresponding title compounds via regioselective 1,3-dipolar cycloaddition in m...Additions of diethyl phosphite to α-nitroalkenes followed by the introduction of trimethylchlorosilane and an activated alkene, gave the corresponding title compounds via regioselective 1,3-dipolar cycloaddition in moderate yield.展开更多
The solid-phase synthesis of isoxazolines on 2-polystyrylsulfonamidoethanol resin is reported. 2-Polystyrylsulfonamidoethanol resin 1 was reacted with acryloyl chloride to afford 2-polystyrylsulfonylamidoethyl acrylat...The solid-phase synthesis of isoxazolines on 2-polystyrylsulfonamidoethanol resin is reported. 2-Polystyrylsulfonamidoethanol resin 1 was reacted with acryloyl chloride to afford 2-polystyrylsulfonylamidoethyl acrylate resin 2, which was further reacted with brominated aldoximes by [3+2] cycloaddition to give isoxazoline resin 4. Resin 4 was treated with aqueous 6 mol/L HCl solution to obtain isoxazolines in good yield and purity.展开更多
An efficient liquid-phase synthesis of isoxazolines through a 1,3-dipolar cycloaddition is described. Soluble polymer-supported acrylate reacted with nitrile oxides generated in-situ, followed by cleavage from the sup...An efficient liquid-phase synthesis of isoxazolines through a 1,3-dipolar cycloaddition is described. Soluble polymer-supported acrylate reacted with nitrile oxides generated in-situ, followed by cleavage from the support giving corresponding isoxazolines in high yields and excellent purities.展开更多
NTrifluoromethyl and cyclopropyl substituted 2-isoxazolines were synthesized via a DBU-promoted domino reaction of β-trifluoromethyl-/β-cyclopropyl-substituted enones with hydroxylamine. The domino reaction consists...NTrifluoromethyl and cyclopropyl substituted 2-isoxazolines were synthesized via a DBU-promoted domino reaction of β-trifluoromethyl-/β-cyclopropyl-substituted enones with hydroxylamine. The domino reaction consists of a Michael addition and the followed cyclization. A wide range of 3-substituted 5-cyclopropyl-5-trifluoromethyl-2-isoxazolines were obtained in good to excellent yields under mild reaction conditions. The method could also apply to other trifluoromethyl-substituted enones.展开更多
The crystal structure of the title compound, diethyl 5-acetoxy-3-（4-chlorophenyl）-4,5- dihydroisoxazol-5-yl-5-phosphonate （C15H19CINO6P, Mr = 375.73）, has been synthesized by the treatment of nitrile oxides and l-...The crystal structure of the title compound, diethyl 5-acetoxy-3-（4-chlorophenyl）-4,5- dihydroisoxazol-5-yl-5-phosphonate （C15H19CINO6P, Mr = 375.73）, has been synthesized by the treatment of nitrile oxides and l-acetyloxy-vinylphosphonate under very mild conditions in good yields, and determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group C2/c with a = 16.914（10）, b = 10.567（7）, c = 21.927（13） A, β = 110.249（11）°, V = 3677（4） A^3, Z = 8, Dc = 1.358 g/cm^3, F（000） = 1568,/l（MoKa） = 0.324 mm^-1）, S = 1.011, the final R = 0.0661 and wR = 0.1556. The X-ray analytic results showed that the dihedral angle between the phenyl group and the isoxazoline ring is 10.7°.展开更多
The first example of stereoconvergent 1,3-dipolar cycloaddition of nitrile oxides and nitrile imines with E/Z isomeric mixture of electron-deficient olefins is reported,delivering isoxazolines and pyrazolines bearing ...The first example of stereoconvergent 1,3-dipolar cycloaddition of nitrile oxides and nitrile imines with E/Z isomeric mixture of electron-deficient olefins is reported,delivering isoxazolines and pyrazolines bearing two vicinal stereogenic tertiary and trifluoromethylated quaternary carbon centers with perfect regioand diastereoselectivities.The possibility of concerted cycloaddition/epimerization sequence under basic condition to form the thermodynamically stable diastereomers is excluded through some control experiments and DFT calculations,and a stepwise mechanism is proposed.展开更多
文摘An expeditious and effective method for synthesis of isoxazoline from aldoximes and activated alkenes using cetyltrimethylammonium cerium nitrate at room temperature is described.Reaction was completed within short time period in high yields at room temperature.
基金We are grateful to the National Natural Science Foundation of China(20332060)the CAS Academician Foundation of Zhejiang Province.
文摘A mild deselenenylation reaction protocol for the preparation of 3, 5-disubstituted isoxazolines and their further application to 3-methyl-5-substituted isoxazoles both in solution phase and solid phase was reported.
文摘An efficient and rapid parallel liquid-phase synthesis of isoxazolines has been reported. The one-pot three-component reaction of polyethylene glycol-supported acrylates, aldehydes and hydroxylamine hydrochloride in the presence of chloramine-T in methanol gave the corresponding PEG-supported isoxazolines, which can be cleaved from the support under mild condition to afford isoxazolines in good yields (>80%) and high purities (>86%).
文摘A mild, regioselective 1, 3-dipolar cycloaddition protocol for the preparation of phenylselenomethyl isoxazolines through substituted allyl phenyl selenides and nitrile oxides was reported.
文摘Additions of diethyl phosphite to α-nitroalkenes followed by the introduction of trimethylchlorosilane and an activated alkene, gave the corresponding title compounds via regioselective 1,3-dipolar cycloaddition in moderate yield.
基金NNSFC (20074017,29844001) and Visiting Scholar Foundation of Key Lab. In University
文摘The solid-phase synthesis of isoxazolines on 2-polystyrylsulfonamidoethanol resin is reported. 2-Polystyrylsulfonamidoethanol resin 1 was reacted with acryloyl chloride to afford 2-polystyrylsulfonylamidoethyl acrylate resin 2, which was further reacted with brominated aldoximes by [3+2] cycloaddition to give isoxazoline resin 4. Resin 4 was treated with aqueous 6 mol/L HCl solution to obtain isoxazolines in good yield and purity.
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No .2 9972 0 37)
文摘An efficient liquid-phase synthesis of isoxazolines through a 1,3-dipolar cycloaddition is described. Soluble polymer-supported acrylate reacted with nitrile oxides generated in-situ, followed by cleavage from the support giving corresponding isoxazolines in high yields and excellent purities.
基金Supports from the National Natural Science Foundation of China (Nos. 21272257, 21274041 and 21474028)
文摘NTrifluoromethyl and cyclopropyl substituted 2-isoxazolines were synthesized via a DBU-promoted domino reaction of β-trifluoromethyl-/β-cyclopropyl-substituted enones with hydroxylamine. The domino reaction consists of a Michael addition and the followed cyclization. A wide range of 3-substituted 5-cyclopropyl-5-trifluoromethyl-2-isoxazolines were obtained in good to excellent yields under mild reaction conditions. The method could also apply to other trifluoromethyl-substituted enones.
文摘The crystal structure of the title compound, diethyl 5-acetoxy-3-（4-chlorophenyl）-4,5- dihydroisoxazol-5-yl-5-phosphonate （C15H19CINO6P, Mr = 375.73）, has been synthesized by the treatment of nitrile oxides and l-acetyloxy-vinylphosphonate under very mild conditions in good yields, and determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group C2/c with a = 16.914（10）, b = 10.567（7）, c = 21.927（13） A, β = 110.249（11）°, V = 3677（4） A^3, Z = 8, Dc = 1.358 g/cm^3, F（000） = 1568,/l（MoKa） = 0.324 mm^-1）, S = 1.011, the final R = 0.0661 and wR = 0.1556. The X-ray analytic results showed that the dihedral angle between the phenyl group and the isoxazoline ring is 10.7°.
基金the financial support for this investigation from the National Natural Science Foundation of China(Nos.21772151,22072111)the Fundamental Research Funds for Central Universities(No.WUT:2021IVA121).
文摘The first example of stereoconvergent 1,3-dipolar cycloaddition of nitrile oxides and nitrile imines with E/Z isomeric mixture of electron-deficient olefins is reported,delivering isoxazolines and pyrazolines bearing two vicinal stereogenic tertiary and trifluoromethylated quaternary carbon centers with perfect regioand diastereoselectivities.The possibility of concerted cycloaddition/epimerization sequence under basic condition to form the thermodynamically stable diastereomers is excluded through some control experiments and DFT calculations,and a stepwise mechanism is proposed.
