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Alternative Construction of the Core of Lindenane Sesquiterpenoid

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Chinese Journal of Chemistry 2023年第16期41卷 1931-1936页

作者： Cichang Ling Zhengsong Huang yuqiao zhou Shaomin Fu Bo Liu Key Laboratory of Green Chemistry&TechnologyofMinistryof Education Collegeof ChemistrySichuan UniversityChengduSichuan 610064China

Comprehensive Summary Alternative synthetic routes toward the tricyclic core of lindenane sesquiterpenoid are presented herein.The route A features an asymmetric organocatalysis enabling desymmetric silylation of diol to establish the desired tertiary alcohol,while the route B consists of an acetate ring opening of chiral epoxy moiety.The common intermediate(16)in both routes can give rise to the core of lindenane sesquiterpenoid via an intramolecular cyclopropanation.

关键词： Terpenoid Lindenane Total synthesis Desymmetrization Epoxidation Nucleophilic substitution Cycloaddition Cyclopropanation

Asymmetric catalytic nitrooxylation and azidation of β-keto amides/esters with hypervalent iodine reagents

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Organic Chemistry Frontiers 2022年第3期9卷 703-708页

作者： Changqiang He Zhikun Wu yuqiao zhou Weidi Cao Xiaoming Feng Key laboratory of Green Chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610064China

Chiral Lewis acid-catalyzed enantioselective nitrooxylation of cyclic and acyclicβ-keto amides/esters with hypervalent iodine(III)reagents is reported.A number ofα-nitrooxy-β-keto amides/esters were obtained with g... 详细信息

关键词： conditions esters iodine

Highly diastereoselective cascade dearomatization of 3-(2-isocyanoethyl)indoles with nitrile imines: a facile access to unexpected polycyclic indolines

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Organic Chemistry Frontiers 2022年第5期9卷 1336-1342页

作者： Xiaohu Zhao yuqiao zhou Bao-Lin Li Guangxi Du Zhipeng Yu Key Laboratory of Green Chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610064China

A highly efficient dearomatization of 3-(2-isocyanoethyl)indoles with in situ generated nitrile imines has been developed through a nucleophilic/Friedel–Crafts/aza-Mannich type cascade and 1,3-dipolar cyclo-addition reaction under catalyst-free and mild reaction conditions.This strategy offers a novel and con-venient route to the rapid assembly of a wide range of unprecedented polycyclic indoline scaffolds in moderate to excellent yields and diastereoselectivities.

关键词： conditions nitrile indole

New chiral N-heterocyclic olefin bifunctional organocatalysis inα-functionalization ofβ-ketoesters

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Science China Chemistry 2023年第1期66卷 147-154页

作者： Sijing Wang Cefei Zhang Da Li yuqiao zhou Zhishan Su Xiaoming Feng Shunxi Dong Key Laboratory of Green Chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610064China

N-heterocyclic olefins(NHOs)possess an electron-rich and highly polarized C=C double bond due to the donating property of nitrogen atoms.This feature imparts exocyclic carbon atom of NHOs with strong basicity and high nucleophilicity.Although NHOs have been emerging as a new type of organocatalyst and ligand for metal complexes in organic synthesis,chiral NHOmediated highly enantioselective organic transformations were still elusive.Herein,we developed a new type of chiral aminederived C_(2)-symmetric NHOs and employed them as efficient chiral bifunctional organocatalysts for asymmetricα-functionalization ofβ-ketoesters.With as low as 0.1 mol%catalyst loading,the desired amination and trifluoromethylthiolation products were afforded in good yields with high enantioselectivities(up to 99%yield and 99%ee).Experimental studies and theoretical calculation disclosed that hydrogen-bonding interaction upon protonation and other weak interaction between substrate and catalyst were crucial for the enantiocontrol.

关键词： organocatalyst N-heterocyclic olefin asymmetric synthesis amination trifluoromethylthiolation

Construction of Angularly Fused Tricyclic Compounds via Photo-induced Radical Cascade Cyclization

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Chinese Journal of Chemistry 2023年第19期41卷 2502-2506页

作者： Mengqin Hu Wei Cao Zhen Wang Yan Hao Ganxing Huang yuqiao zhou Song Qin Shaomin Fu Bo Liu Key Laboratory of Green Chemistry&Technology of Ministry of Education College of ChemistrySichuan UniversityChengduSichuan610064 China

Photo-induced electron transfer (PET) of silyl enol ethers has been employed to synthesize several fused ring systems. However, the method has limited applicability due to its narrow substrate scope, low product yields, unsatisfactory stereo- and regioselectivity. Herein, we report a PET-triggered cascade reaction of silyl enolates that leads to the formation of angularly fused tricyclic scaffolds. The reaction exhibits broad substrate scope and excellent stereoselectivity. The regio- and stereoselectivity of this cascade reaction is elucidated via DFT calculation and conformational analysis.

关键词： Cyclization Radical Tricyclic compounds Photocatalysis Enols Fused-ring systems Domino reactions Regioselectivity

Catalytic Asymmetric[3+2]Cycloaddition of Exocyclic Enol Ethers for the Synthesis of Spiroketals

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Precision Chemistry

Precision Chemistry 2023年第7期1卷 423-428页

作者： Fengcai Zhang yuqiao zhou Hansen Zhao Long Chen Weidi Cao Xiaoming Feng Key Laboratory of Green Chemistry and Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610064China

An efficient synthesis of chiral benzannulated spiroketals via catalytic asymmetric[3+2]cycloaddition of exocyclic enol ethers with p-quinones was achieved.The transformation was enabled by a chiral N,N′-dioxides/Tm^(Ⅲ)complex as the Lewis acid catalyst and afforded a series of enantiomerically enriched benzannulated spiroketal derivatives in good yields(up to 99%)and enantioselectivities(up to 98%ee).Topographic steric maps and distribution of the buried volumes of the catalysts via Cavallo’s SambVca 2 tool were used to elucidate the enantioinduction raised by the ligands and the metal ions.

关键词： asymmetric catalysis [3+2]-cycloaddition spiroketals exocyclic enol ethers quinones

Regio-and enantioselective conjugate addition ofβ-nitroα,β-unsaturated carbonyls to construct 3-alkenyl disubstituted oxindoles

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Chinese Chemical Letters 2023年第1期34卷 337-341页

作者： Changli He Xiaoxue Tang Xin He yuqiao zhou Xiaohua Liu Xiaoming Feng Key Laboratory of Green Chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610064China

Reversal of regioselectivity in the catalytic asymmetric conjugate additions of 3-substituted oxindoles toβ-nitroenones orβ-nitroacrylates was established with chiral scandium catalysts.It enabled the construction of functionalized 3,3-disubstituted oxindoles,including terminal and internal vinyl groups in excellent yields and ee values.

关键词： Asymmetric catalysis Conjugate addition Nitroalkenes Regioselectivity Oxindoles

Asymmetric Catalytic Concise Synthesis of Hetero-3,3′-Bisoxindoles for the Construction of Bispyrroloindoline Alkaloids

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CCS Chemistry 2021年第7期3卷 1894-1902页

作者： Jian Xu Ziwei Zhong Mingyi Jiang yuqiao zhou Xiaohua Liu Xiaoming Feng Key Laboratory of Green Chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610065

Asymmetric nucleophilic addition of 3-substituted NBoc oxindoles to 3-bromooxindoles was designed to directly construct hetero-3,3′-bisoxindoles,with varying vicinal quaternary carbon stereocenters and N-substituents.The reaction progressed efficiently with high yields,good diastereo-and enantioselectivity(up to>99%ee)under mild reaction conditions catalyzed by chiral N,N′-dioxide/metal complexes.This methodology enabled the facile transformation of the generated hetero-3,3’-bisoxindoles into diverse hexahydropyrroloindole alkaloids with potential antiparasitic and anticancer properties.

关键词： asymmetric catalysis 3 3′-disubstituted bisoxindoles chiral N N′-dioxide hexahydropyrroloindole alkaloids quaternary stereocenters

实用化导向的X射线晶体学与结构解析教学改革探索

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大学化学 2024年第3期39卷 23-28页

作者：周宇乔曹伟地董顺喜林丽丽刘小华四川大学化学学院绿色化学与技术教育部重点实验室成都610064

结构决定性能。物质结构是当代化学、材料、生物学科前沿探索的基石和导引,测定解析物质结构是很多科研工作者必备的技能和研究手段。X射线衍射是结构测定最常见的方法之一。在科研一线工作的师生对X射线晶体学知识和结构解析技能有着... 详细信息

结构决定性能。物质结构是当代化学、材料、生物学科前沿探索的基石和导引,测定解析物质结构是很多科研工作者必备的技能和研究手段。X射线衍射是结构测定最常见的方法之一。在科研一线工作的师生对X射线晶体学知识和结构解析技能有着大量的需求。然而,当前国内高校开设专业X射线晶体学课程较少,课程内容理论性强,实践环节不足,不能完全满足非晶体专业方向学生需求。面对X射线衍射结构解析的实际问题,学生难以从传统课程和导师等渠道得到足够支持帮助,需求和供给存在缺口。本文分析国内X射线晶体学教学和知识传播现状以及存在的问题,从知识提升、技能培养和信心树立三个方面针对性地改革X射线晶体学与结构解析的教学方式和内容,通过将传统课程拆分为X射线衍射原理、简明晶体学和结构解析技术三部分,扩充实践内容环节,特别是晶体数据收集和结构解析精修的要点技巧,辅以必要的基础理论知识,有效补充广大非晶体专业方向师生亟需的X射线晶体学基础知识和结构解析技术,围绕学生科研一线实际需要,以提升实战技能来解决学生的痛点和难点,同时树立学生面对结构解析的自信心。

关键词：实用X射线晶体学结构解析教学改革