环己酮是重要的化工原料,是生产尼龙6和尼龙66重要中间体,环己酮结构还存在于自然界中,是一类具有多种生物活性的药物骨架。本论文以双苄叉丙酮与丙二腈为原料,以DMF(N,N-二甲基甲酰胺)为溶剂,K_(2)CO_(3)为碱,且在无催化剂的条件下发生...环己酮是重要的化工原料,是生产尼龙6和尼龙66重要中间体,环己酮结构还存在于自然界中,是一类具有多种生物活性的药物骨架。本论文以双苄叉丙酮与丙二腈为原料,以DMF(N,N-二甲基甲酰胺)为溶剂,K_(2)CO_(3)为碱,且在无催化剂的条件下发生[5+1]环化反应,合成了一系列多取代环己酮类化合物,其结构经1 H NMR,^(13)C NMR、HR-MS(ESI)和IR表征,并对该合成反应机理进行了探讨。该合成方法具有宽泛的底物普适性,条件温和,较高的原子经济性和收率高等优势。展开更多
The chemoselective C-and O-prenylation of cyclic 1,3-diketones was achieved by tuning the prenyl source and catalyst.In the presence of the solid acid Nafion,the coupling of 1,3-cyclohexanediones with isoprene gave C-...The chemoselective C-and O-prenylation of cyclic 1,3-diketones was achieved by tuning the prenyl source and catalyst.In the presence of the solid acid Nafion,the coupling of 1,3-cyclohexanediones with isoprene gave C-prenylated 5-chromenones.Alternatively,using prenol as the substrate with the Lewis acid Al Cl3 as the catalyst resulted in the exclusive O-prenylation of 1,3-cyclohexanediones.Notably,the resulting products could easily undergo aromatization to deliver prenylated resorcinols that are otherwise difficult to prepare.Our methodology is highly selective,atom-economical,operationally simple,easily scalable,and has potential applications throughout organic synthesis.展开更多
A new Rh(Ⅲ)-catalyzed aldehydic C-H activation/[4+3]annulation cascade of N-sulfonyl-2-aminobenzaldehydes with gem-difluorocyclopropenes is reported for the first time,and used to produce a range of hitherto unreport...A new Rh(Ⅲ)-catalyzed aldehydic C-H activation/[4+3]annulation cascade of N-sulfonyl-2-aminobenzaldehydes with gem-difluorocyclopropenes is reported for the first time,and used to produce a range of hitherto unreported precedentedβ-monofluorinated benzo[b]azepin-5-ones with good yields and complete regioselectivity.This approach features a broad substrate scope,good functional group tolerance,and high regioselectivity,which may include Rh(Ⅲ)-catalyzed aldehydic C-H activation,tandem site-/regioselective insertion,defluorinated ring-scission,and 1,2-elimination.展开更多
A new palladium-catalyzed annulative allylic alkylation(AAA)reaction of 2-(indol-2-yl)phenols with dual allylic electrophiles such as isobutylene dicarbonate and butene dicarbonate is described,leading to the regiosel...A new palladium-catalyzed annulative allylic alkylation(AAA)reaction of 2-(indol-2-yl)phenols with dual allylic electrophiles such as isobutylene dicarbonate and butene dicarbonate is described,leading to the regioselective synthesis of tetracyclic medium-sized cyclic ethers possessing a bridged aryl-indole scaf-fold,namely,benzo[2,3]oxocino[4,5-b]indoles and benzo[2,3]oxepino[4,5-b]indoles,in good to excellent yields.This protocol demonstrates a broad substrate scope,good compatibility with substituents and high regioselectivity,providing a catalytic and flexible method for creating bridged aryl-indole skeletons.展开更多
Palladium-catalyzed oxidative formal [4 + 1] annulation of pyridine-substituted acrylonitriles toward divergent fused N-heterocycles synthesis is reported. The heterodifunctionalization reaction with Cu(OAc);and urea ...Palladium-catalyzed oxidative formal [4 + 1] annulation of pyridine-substituted acrylonitriles toward divergent fused N-heterocycles synthesis is reported. The heterodifunctionalization reaction with Cu(OAc);and urea as the nitrogen source accesses to nitrile-substituted pyrazolo[1,5-a]pyridines in moderate to good yields, while the homodifunctionalization reaction with FeBr;leads to synthesis of nitrilesubstituted indolizines in excellent yields.展开更多
Atkamine is a complex marine pyrroloiminoquinone alkaloid that comprises a heptacyclic scaffold bearing five different heterocycles and four contiguous stereocenters,and therefore it is a highly challenging target for...Atkamine is a complex marine pyrroloiminoquinone alkaloid that comprises a heptacyclic scaffold bearing five different heterocycles and four contiguous stereocenters,and therefore it is a highly challenging target for synthetic chemists.We herein reported a modular synthetic strategy toward this alkaloid,featuring a formal [5+2] annulation and an asymmetric Michael addition.The efficient synthesis of the long-chain aliphatic aldehyde and chiral amino acetal fragments have been achieved.A simplified tetracyclic intermediate bearing the core structure of atkamine has been successfully constructed through the formal [5+2] annulation.展开更多
文摘环己酮是重要的化工原料,是生产尼龙6和尼龙66重要中间体,环己酮结构还存在于自然界中,是一类具有多种生物活性的药物骨架。本论文以双苄叉丙酮与丙二腈为原料,以DMF(N,N-二甲基甲酰胺)为溶剂,K_(2)CO_(3)为碱,且在无催化剂的条件下发生[5+1]环化反应,合成了一系列多取代环己酮类化合物,其结构经1 H NMR,^(13)C NMR、HR-MS(ESI)和IR表征,并对该合成反应机理进行了探讨。该合成方法具有宽泛的底物普适性,条件温和,较高的原子经济性和收率高等优势。
基金The authors gratefully acknowledge financial support from the National Natural Science Foundation of China(No.39370809)National New Drug Foundation(No.92-08-N).
文摘AF-5 was synthesized through a convergent method. The key step was the Robinson annulation using a key intermediate pentyl vinyl ketone.
文摘The chemoselective C-and O-prenylation of cyclic 1,3-diketones was achieved by tuning the prenyl source and catalyst.In the presence of the solid acid Nafion,the coupling of 1,3-cyclohexanediones with isoprene gave C-prenylated 5-chromenones.Alternatively,using prenol as the substrate with the Lewis acid Al Cl3 as the catalyst resulted in the exclusive O-prenylation of 1,3-cyclohexanediones.Notably,the resulting products could easily undergo aromatization to deliver prenylated resorcinols that are otherwise difficult to prepare.Our methodology is highly selective,atom-economical,operationally simple,easily scalable,and has potential applications throughout organic synthesis.
基金financial support from the schoollevel research projects of Yancheng Institute of Technology(No.xjr2020044)the National Natural Science Foundation of China(Nos.22101151 and 21971090)。
文摘A new Rh(Ⅲ)-catalyzed aldehydic C-H activation/[4+3]annulation cascade of N-sulfonyl-2-aminobenzaldehydes with gem-difluorocyclopropenes is reported for the first time,and used to produce a range of hitherto unreported precedentedβ-monofluorinated benzo[b]azepin-5-ones with good yields and complete regioselectivity.This approach features a broad substrate scope,good functional group tolerance,and high regioselectivity,which may include Rh(Ⅲ)-catalyzed aldehydic C-H activation,tandem site-/regioselective insertion,defluorinated ring-scission,and 1,2-elimination.
基金the National Natural Science Foundation of China(Nos.21971090 and 22271123).
文摘A new palladium-catalyzed annulative allylic alkylation(AAA)reaction of 2-(indol-2-yl)phenols with dual allylic electrophiles such as isobutylene dicarbonate and butene dicarbonate is described,leading to the regioselective synthesis of tetracyclic medium-sized cyclic ethers possessing a bridged aryl-indole scaf-fold,namely,benzo[2,3]oxocino[4,5-b]indoles and benzo[2,3]oxepino[4,5-b]indoles,in good to excellent yields.This protocol demonstrates a broad substrate scope,good compatibility with substituents and high regioselectivity,providing a catalytic and flexible method for creating bridged aryl-indole skeletons.
基金financial support from the Natural Science Foundation of Jiangxi Provincial Education Department (Nos. GJJ201422, GJJ190754, GJJ190776)Science and Technology Project of Ganzhou City。
文摘Palladium-catalyzed oxidative formal [4 + 1] annulation of pyridine-substituted acrylonitriles toward divergent fused N-heterocycles synthesis is reported. The heterodifunctionalization reaction with Cu(OAc);and urea as the nitrogen source accesses to nitrile-substituted pyrazolo[1,5-a]pyridines in moderate to good yields, while the homodifunctionalization reaction with FeBr;leads to synthesis of nitrilesubstituted indolizines in excellent yields.
基金the National Natural Science Foundation of China for financial support of this work by grants (Nos.21772164 and 21572187)the National Found for Fostering Talents of Basic Science (NFFTBS,No.J1310024)+1 种基金New Century Excellent Talents in University of Fujian Province (NECTFJ)Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT) for support。
文摘Atkamine is a complex marine pyrroloiminoquinone alkaloid that comprises a heptacyclic scaffold bearing five different heterocycles and four contiguous stereocenters,and therefore it is a highly challenging target for synthetic chemists.We herein reported a modular synthetic strategy toward this alkaloid,featuring a formal [5+2] annulation and an asymmetric Michael addition.The efficient synthesis of the long-chain aliphatic aldehyde and chiral amino acetal fragments have been achieved.A simplified tetracyclic intermediate bearing the core structure of atkamine has been successfully constructed through the formal [5+2] annulation.
