A gold（I）-catalyzed highly diastereo- and enantioselective intermolecular cycloaddition of oxime ethers with nitrones under mild conditions was developed, which provides an facile access to optically pure highly sub...A gold（I）-catalyzed highly diastereo- and enantioselective intermolecular cycloaddition of oxime ethers with nitrones under mild conditions was developed, which provides an facile access to optically pure highly substituted pyrrolo[3,4-d][1,2]oxazines. The salient features of this reaction in- clude general substrate scope, high efficiency, high enantioselectivity, readily available starting materials, and the use of commercially available ligand.展开更多
α-Aryl nitrone are one of the most useful kinds of nitrones and have been extensively explored in recent years.However,the sugar moieties have not been introduced into these molecules before.We presented here an effi...α-Aryl nitrone are one of the most useful kinds of nitrones and have been extensively explored in recent years.However,the sugar moieties have not been introduced into these molecules before.We presented here an efficient synthesis ofα-aryl nitrone Oglycosides via condensation of N-substituted hydroxylamine and aryl aldehydes glycosides in benzene.展开更多
A new organocatalytic double annulation cascade involving scission/recombination of N-O bonds of nitrones is reported for the first time, and used to produce a range of hitherto unprecedented tricyclic bridged-fused b...A new organocatalytic double annulation cascade involving scission/recombination of N-O bonds of nitrones is reported for the first time, and used to produce a range of hitherto unprecedented tricyclic bridged-fused benzo[d]azepines bearing three stereogenic centers with moderate to good yields and complete diastereoselectivity. A quinine-catalyzed reaction of yne–allenone esters with nitrones worked well and provided a convergent and regioselective pathway to access these three-dimensional scaffolds from the planar conjugated system. Density functional theory(DFT) calculations have been applied to understand the key process for forming diradical intermediates.展开更多
A [3＋3] formal cycloaddition reaction between in situ formed azaoxyallyl cations and nitrones from isatins has been developed, furnishing a spectrum of spiro[1,2,4-oxadiazinan-5-one]oxindoles in good to excellent yie...A [3＋3] formal cycloaddition reaction between in situ formed azaoxyallyl cations and nitrones from isatins has been developed, furnishing a spectrum of spiro[1,2,4-oxadiazinan-5-one]oxindoles in good to excellent yields with excellent diastereoselectivity. This method provides direct and efficient access to potentially bioactive spirooxin- doles incorporating a six-membered heterocyclic scaffold.展开更多
Benzohydroxamic acid reacts with dimethyl acetylenedicarboxylate in the presence of 10 mol% NaOAc to gen- erate （E）-N-（1,4-dimethoxy-l,4-dioxobutan-2-ylidene）-l-phenylcarboxamide oxide in good-to-excellent yield i...Benzohydroxamic acid reacts with dimethyl acetylenedicarboxylate in the presence of 10 mol% NaOAc to gen- erate （E）-N-（1,4-dimethoxy-l,4-dioxobutan-2-ylidene）-l-phenylcarboxamide oxide in good-to-excellent yield in water at room temperature for 2 h, which supplies a simple, efficient and environmentally friendly method to syn- thesize a wide range of nitrones. The benefits of this strategy not only conform to the requirment of green chemisty, but also possess atom economy.展开更多
The behaviour of cyanothioacetamide 1 and the acetonitrile derivatives 6 and 10, respectively, towards the nitrones 2a-i induced by free solar thermal energy is reported. Structures and reaction mechanisms are also di...The behaviour of cyanothioacetamide 1 and the acetonitrile derivatives 6 and 10, respectively, towards the nitrones 2a-i induced by free solar thermal energy is reported. Structures and reaction mechanisms are also discussed.展开更多
基金We are grateful to the National Natural Science Foundation of China （21425205）, Ministry of Education of China, Ying Tung Education Foundation （121014） for financial support.
文摘A gold（I）-catalyzed highly diastereo- and enantioselective intermolecular cycloaddition of oxime ethers with nitrones under mild conditions was developed, which provides an facile access to optically pure highly substituted pyrrolo[3,4-d][1,2]oxazines. The salient features of this reaction in- clude general substrate scope, high efficiency, high enantioselectivity, readily available starting materials, and the use of commercially available ligand.
基金support from National Natural Science Foundation of China(No.20962017) the Natural Science Foundation of Gansu Province,China(No.2007GS03630)
文摘α-Aryl nitrone are one of the most useful kinds of nitrones and have been extensively explored in recent years.However,the sugar moieties have not been introduced into these molecules before.We presented here an efficient synthesis ofα-aryl nitrone Oglycosides via condensation of N-substituted hydroxylamine and aryl aldehydes glycosides in benzene.
基金financial support from the National Natural Science Foundation of China (Nos. 21871112 and 21971090)。
文摘A new organocatalytic double annulation cascade involving scission/recombination of N-O bonds of nitrones is reported for the first time, and used to produce a range of hitherto unprecedented tricyclic bridged-fused benzo[d]azepines bearing three stereogenic centers with moderate to good yields and complete diastereoselectivity. A quinine-catalyzed reaction of yne–allenone esters with nitrones worked well and provided a convergent and regioselective pathway to access these three-dimensional scaffolds from the planar conjugated system. Density functional theory(DFT) calculations have been applied to understand the key process for forming diradical intermediates.
文摘A [3＋3] formal cycloaddition reaction between in situ formed azaoxyallyl cations and nitrones from isatins has been developed, furnishing a spectrum of spiro[1,2,4-oxadiazinan-5-one]oxindoles in good to excellent yields with excellent diastereoselectivity. This method provides direct and efficient access to potentially bioactive spirooxin- doles incorporating a six-membered heterocyclic scaffold.
文摘Benzohydroxamic acid reacts with dimethyl acetylenedicarboxylate in the presence of 10 mol% NaOAc to gen- erate （E）-N-（1,4-dimethoxy-l,4-dioxobutan-2-ylidene）-l-phenylcarboxamide oxide in good-to-excellent yield in water at room temperature for 2 h, which supplies a simple, efficient and environmentally friendly method to syn- thesize a wide range of nitrones. The benefits of this strategy not only conform to the requirment of green chemisty, but also possess atom economy.
文摘The behaviour of cyanothioacetamide 1 and the acetonitrile derivatives 6 and 10, respectively, towards the nitrones 2a-i induced by free solar thermal energy is reported. Structures and reaction mechanisms are also discussed.
基金supported by the Dalian Institute of Chemical Physics,Chinese Academy of Sciencesthe National Natural Science Foundation of China(21272231,21472186,21372266)~~
