The cycloaddition of N-acyliminium cations with some deactivated alkenes such as α,β-unsaturate ketones and esters has been investigated. In most cases, the N-acyliminium cations produced from 3-hydroxy-2-arylisoind...The cycloaddition of N-acyliminium cations with some deactivated alkenes such as α,β-unsaturate ketones and esters has been investigated. In most cases, the N-acyliminium cations produced from 3-hydroxy-2-arylisoindol-1-ones in the presence of BFa.OEt2 could be reacted with α,β-unsaturated ketones and esters to afford stereoselectively the cycloaddition products 6-acylisoindolo[2,1- a]quinolin-11-ones in moderate to high yields. C 2009 Wei Zhang. Published by Elsevier B.V, on behalf of Chinese Chemical Society. All rights reserved.展开更多
An efficient approach to functionalized 4,6-disubstituted-and 4,6,6-trisubstituted-1,3-oxazinan-2-ones skeleton has been developed through the reaction of semicyclic N,O-acetals 4a and 4b with 1,1-disubstituted ethyle...An efficient approach to functionalized 4,6-disubstituted-and 4,6,6-trisubstituted-1,3-oxazinan-2-ones skeleton has been developed through the reaction of semicyclic N,O-acetals 4a and 4b with 1,1-disubstituted ethylenes 5 or 8.As a result of such a[4+2]cycloaddition process,4,6,6-trisubstituted-1,3-oxazinan-2-ones 6aa,6af-6au,7ba,7bf-7bw and 6,6-spiro containing 1,3-oxazinan-2-ones 9ad,9ae,10ba-10bg were obtained in 36%-96%yields and with moderate to excellent diastereoselectivities.In addition,the synthesis of(±)-norallosedamine 12 could be conveniently achieved from the cycloadduct 7bf.展开更多
A novel catalytic reaction has been developed for the nucleophilic addition of terminal alkynes toα,β‐unsaturated‐γ‐lactams via a cyclic N‐acyliminium ion intermediate. This simple reaction pro‐ceeds rapidly u...A novel catalytic reaction has been developed for the nucleophilic addition of terminal alkynes toα,β‐unsaturated‐γ‐lactams via a cyclic N‐acyliminium ion intermediate. This simple reaction pro‐ceeds rapidly under mild conditions, and provided a practical approach for the synthesis of a wide range of 5‐alkynyl‐2‐pyrrolidinones in moderate to good yields （45%–76%）.展开更多
2, 3, 11, 12-Tetramethoxy-3b, 4, 5, 6-tetrahydro-8H-7a-aza-benzo[fg]naphthacen-7-one 7 was synthesized via N-acyliminium ion cyclization of 6-hydroxy-1-(2, 3, 6, 7-tetramethoxy- phenanthren-9-yl-methyl)-piperidin-2-on...2, 3, 11, 12-Tetramethoxy-3b, 4, 5, 6-tetrahydro-8H-7a-aza-benzo[fg]naphthacen-7-one 7 was synthesized via N-acyliminium ion cyclization of 6-hydroxy-1-(2, 3, 6, 7-tetramethoxy- phenanthren-9-yl-methyl)-piperidin-2-one 6 catalyzed by BF3OEt2. The stereostructure of the intermediate, 1-(2, 3, 6, 7-tetramethoxy-phenanthren-9-yl-methyl)-piperidine-2, 6-dione 5, was confirmed by X-ray crystallographic analysis. Compound 7 showed no cytotoxicity.展开更多
基金the National Natural Science Foundation of China(No.20872056) for financial support.
文摘The cycloaddition of N-acyliminium cations with some deactivated alkenes such as α,β-unsaturate ketones and esters has been investigated. In most cases, the N-acyliminium cations produced from 3-hydroxy-2-arylisoindol-1-ones in the presence of BFa.OEt2 could be reacted with α,β-unsaturated ketones and esters to afford stereoselectively the cycloaddition products 6-acylisoindolo[2,1- a]quinolin-11-ones in moderate to high yields. C 2009 Wei Zhang. Published by Elsevier B.V, on behalf of Chinese Chemical Society. All rights reserved.
基金the National Natural Science Foundation of China(No.21772027 to B.-G.Wei and 21702032 to C.-M.Si)for financial support.
文摘An efficient approach to functionalized 4,6-disubstituted-and 4,6,6-trisubstituted-1,3-oxazinan-2-ones skeleton has been developed through the reaction of semicyclic N,O-acetals 4a and 4b with 1,1-disubstituted ethylenes 5 or 8.As a result of such a[4+2]cycloaddition process,4,6,6-trisubstituted-1,3-oxazinan-2-ones 6aa,6af-6au,7ba,7bf-7bw and 6,6-spiro containing 1,3-oxazinan-2-ones 9ad,9ae,10ba-10bg were obtained in 36%-96%yields and with moderate to excellent diastereoselectivities.In addition,the synthesis of(±)-norallosedamine 12 could be conveniently achieved from the cycloadduct 7bf.
基金supported by the National Natural Science Foundation of China(21222203,21172226,21133011)
文摘A novel catalytic reaction has been developed for the nucleophilic addition of terminal alkynes toα,β‐unsaturated‐γ‐lactams via a cyclic N‐acyliminium ion intermediate. This simple reaction pro‐ceeds rapidly under mild conditions, and provided a practical approach for the synthesis of a wide range of 5‐alkynyl‐2‐pyrrolidinones in moderate to good yields （45%–76%）.
文摘2, 3, 11, 12-Tetramethoxy-3b, 4, 5, 6-tetrahydro-8H-7a-aza-benzo[fg]naphthacen-7-one 7 was synthesized via N-acyliminium ion cyclization of 6-hydroxy-1-(2, 3, 6, 7-tetramethoxy- phenanthren-9-yl-methyl)-piperidin-2-one 6 catalyzed by BF3OEt2. The stereostructure of the intermediate, 1-(2, 3, 6, 7-tetramethoxy-phenanthren-9-yl-methyl)-piperidine-2, 6-dione 5, was confirmed by X-ray crystallographic analysis. Compound 7 showed no cytotoxicity.
