Catalytic asymmetric transformations of ynamides have attracted considerable attention in recent years.However,most of them were limited to intramolecular reactions or required metal catalysts.Herein,a chiral Br?nsted...Catalytic asymmetric transformations of ynamides have attracted considerable attention in recent years.However,most of them were limited to intramolecular reactions or required metal catalysts.Herein,a chiral Br?nsted acid-catalyzed asymmetric intermolecular[4+2]annulation of ynamides with para-quinone methides(p-QMs)is disclosed,which not only represents the first metal-free protocol for catalytic asymmetric nucleophilic addition of ynamides to electrophiles,but also constitutes the first enantioselective annulation between p-QMs and alkynes.This methodology leads to the practical synthesis of biologically important chiral 4-aryl-3,4-dihydrocoumarins and 4-aryl-coumarins.Preliminary control experiments indicate that the orthohydroxyphenyl substituted p-QMs could isomerize into ortho-quinone methides(o-QMs)in the presence of chiral catalyst,which further react with ynamides via enantioselective[4+2]annulation,to generate the chiral product.展开更多
Catalytic asymmetric dearomatization of indoles and alkynes has received much attention in the past decade because this strategy offers an attractive and alternative way for the efficient synthesis of valuable chiral ...Catalytic asymmetric dearomatization of indoles and alkynes has received much attention in the past decade because this strategy offers an attractive and alternative way for the efficient synthesis of valuable chiral polycyclic indolines. However, these reactions have been mostly limited to transition-metal catalysts, and the related chiral Br■nsted acid catalysis has been scarcely reported. Herein, we disclose a chiral phosphoric acid-catalyzed asymmetric dearomatization of indolyl ynamides by direct activation of alkynes. This metal-free method enables the practical and atom-economical construction of an array of valuable chiral polycyclic indolines in moderate to good yields with high enantioselectivities.展开更多
Under photocatalytic reductive conditions,trifluoromethyl radical addition onto an ynamide followed by cyclization on a benzoyl moiety produces diverse isoindolinone platforms with good yields.The selectivity of the r...Under photocatalytic reductive conditions,trifluoromethyl radical addition onto an ynamide followed by cyclization on a benzoyl moiety produces diverse isoindolinone platforms with good yields.The selectivity of the radical cyclization,N-benzoyl vs.N-benzyl as radical acceptor and the E/Z ratio of isomers have been rationalized by modeling.展开更多
A non-noble metal catalyzed hydrative cyclization of aldehyde-ynamides for efficient and practical synthesis of medium-sized lactams(7-to 9-membered rings)is disclosed.Compared with previous hydrative cyclization for ...A non-noble metal catalyzed hydrative cyclization of aldehyde-ynamides for efficient and practical synthesis of medium-sized lactams(7-to 9-membered rings)is disclosed.Compared with previous hydrative cyclization for the formation of six-membered lactams(cis-form),a totally inverse diastereoselectivity(trans-form)of medium-sized lactams is observed.In addition,this protocol delivers valuable medium-sized lactams in moderate to good yields with high diastereoselectivities.Moreover,a rational mechanism to understand this inversion of diastereoselectivity is proposed based on theoretical calculations.展开更多
A novel BF_(3)-promoted [3+2] annulation of azonaphthalenes and ynamides is described.This protocol provides a modular and efficient entry to functionalized amino benzo[e]indole derivatives smoothly.
A CuSO_4 catalyzed ynamide formation/[4+2] cycloaddition relay reaction was achieved in one-pot.Various 4,7-cis-dihydroindolines were produced in good to high yields. The one-pot operation in conjunction with the chea...A CuSO_4 catalyzed ynamide formation/[4+2] cycloaddition relay reaction was achieved in one-pot.Various 4,7-cis-dihydroindolines were produced in good to high yields. The one-pot operation in conjunction with the cheap and benign copper catalysis renders this reaction highly sustainable.展开更多
基金supported by the Ministry of Science and Technology(MOST)(2021YFC2100100)the National Natural Science Foundation of China(22125108,22121001,92056104)+3 种基金the President Research Funds from Xiamen University(20720210002)the Natural Science Foundation of Jiangsu Province(BK20211059)the Project of Science and Technology of Xuzhou Government(KC22080)the National Fund for Fostering Talents of Basic Science(NFFTBS)(J1310024)。
文摘Catalytic asymmetric transformations of ynamides have attracted considerable attention in recent years.However,most of them were limited to intramolecular reactions or required metal catalysts.Herein,a chiral Br?nsted acid-catalyzed asymmetric intermolecular[4+2]annulation of ynamides with para-quinone methides(p-QMs)is disclosed,which not only represents the first metal-free protocol for catalytic asymmetric nucleophilic addition of ynamides to electrophiles,but also constitutes the first enantioselective annulation between p-QMs and alkynes.This methodology leads to the practical synthesis of biologically important chiral 4-aryl-3,4-dihydrocoumarins and 4-aryl-coumarins.Preliminary control experiments indicate that the orthohydroxyphenyl substituted p-QMs could isomerize into ortho-quinone methides(o-QMs)in the presence of chiral catalyst,which further react with ynamides via enantioselective[4+2]annulation,to generate the chiral product.
基金financial support from the National Natural Science Foundation of China(Nos.22125108,22101238,92056104 and 21772161)the China Postdoctoral Science Foundation(No.2020M680087)+3 种基金the Natural Science Foundation of Fujian Province of China(No.2019J02001)the President Research Funds from Xiamen University(No.20720210002)the Fundamental Research Funds for the Central Universities(No.20720202008)NFFTBS(No.J1310024)。
文摘Catalytic asymmetric dearomatization of indoles and alkynes has received much attention in the past decade because this strategy offers an attractive and alternative way for the efficient synthesis of valuable chiral polycyclic indolines. However, these reactions have been mostly limited to transition-metal catalysts, and the related chiral Br■nsted acid catalysis has been scarcely reported. Herein, we disclose a chiral phosphoric acid-catalyzed asymmetric dearomatization of indolyl ynamides by direct activation of alkynes. This metal-free method enables the practical and atom-economical construction of an array of valuable chiral polycyclic indolines in moderate to good yields with high enantioselectivities.
文摘Under photocatalytic reductive conditions,trifluoromethyl radical addition onto an ynamide followed by cyclization on a benzoyl moiety produces diverse isoindolinone platforms with good yields.The selectivity of the radical cyclization,N-benzoyl vs.N-benzyl as radical acceptor and the E/Z ratio of isomers have been rationalized by modeling.
基金supported by the National Natural Science Foundation of China(92056104 and 21772161)the Natural Science Foundation of Fujian Province of China(2019J02001)+3 种基金the President Research Funds from Xiamen University(20720210002)the National Fund for Fostering Talents of Basic Science(NFFTBS)(J1310024)the Opening Project of PCOSS,Xiamen University(201909)the Bioinformatics Center of Nanjing Agricultural University and the Start-up Research Fund of Nanjing Agricultural University(050-804099)。
文摘A non-noble metal catalyzed hydrative cyclization of aldehyde-ynamides for efficient and practical synthesis of medium-sized lactams(7-to 9-membered rings)is disclosed.Compared with previous hydrative cyclization for the formation of six-membered lactams(cis-form),a totally inverse diastereoselectivity(trans-form)of medium-sized lactams is observed.In addition,this protocol delivers valuable medium-sized lactams in moderate to good yields with high diastereoselectivities.Moreover,a rational mechanism to understand this inversion of diastereoselectivity is proposed based on theoretical calculations.
基金financially supported by the National Natural Science Foundation of China(No.21971222)。
文摘A novel BF_(3)-promoted [3+2] annulation of azonaphthalenes and ynamides is described.This protocol provides a modular and efficient entry to functionalized amino benzo[e]indole derivatives smoothly.
基金the National Natural Science Foundation of China (No. 21672027)QingLan Project of Jiangsu Province (2016)SixTalent-Peaks Program of Jiangsu (2016) for financial support
文摘A CuSO_4 catalyzed ynamide formation/[4+2] cycloaddition relay reaction was achieved in one-pot.Various 4,7-cis-dihydroindolines were produced in good to high yields. The one-pot operation in conjunction with the cheap and benign copper catalysis renders this reaction highly sustainable.
