检索结果-南通市图书馆

Selective Dealkenylative Functionalization of Styrenes via C-C Bond Cleavage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2020年第1期2020卷 1420-1428页

作者： Jianzhong Liu Jun Pan Xiao Luo Xu Qiu Cheng Zhang Ning Jiao State Key Laboratory of Natural and Biomimetic Drugs Peking University100191 BeijingChina State Key Laboratory of Organometallic Chemistry Chinese Academy of SciencesShanghai 200032China

As a readily available feedstock,styrene with about 25 million tons of global annual production serves as an important building block and organic synthon for the synthesis of fine chemicals,polystyrene plastics,and elastomers.Thus,in the past decades,many direct transformations of this costless styrene feedstock were disclosed for the preparation of high-value chemicals,which to date,generally performed on the functionalization of styrenes through the allylic C-H bond,C(sp2)-H bond,or the C=C double bond cleavage.However,the dealkenylative functionalization of styrenes via the direct C-C single bond cleavage is so far challenging and still unknown.Herein,we report the novel and efficient C-C amination and hydroxylation reactions of styrenes for the synthesis of valuable aryl amines and phenols via the site-selective C(Ar)-C(alkenyl)single bond cleavage.This chemistry unlocks the new transformation and application of the styrene feedstock and provides an efficient protocol for the late-stage modification of substituted styrenes with the site-directed dealkenylative amination and hydroxylation.

关键词： styrene cleavage synthesis

Photoinduced C--C Bond Cleavage and Oxidation of CycloketoximeEsters

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2018年第11期36卷 995-999页

作者： Binlin Zhao Hui Tan Cheng Chen Ning Jiao Zhuangzhi Shi State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing Jiangsu 210093 China State Key Laboratory of Natural and Biomimetic Drugs School of Phar-maceutical Sciences Peking University Xue Yuan Road 38 Beijing100191 China

A novel structural reorganization of cycloketoxime esters beyond the traditional Beckmann rearrangement process has been established to build cyano‐containing ketones in the presence of photocatalyst. This novel transformation is remarkable with selective C—C bond cleavage and an oxidation process enabled by DMSO used as the solvent, oxidant, and oxygen source avoiding acid, base and toxic cyanide salts as the cyano source. Further applications in late‐stage modification of complex and chiral molecules have also been reported.

关键词： C—C activation radical cycloketoxime oxygenation photocatalysis DMSO

三氟乙酸酐(TFAA)促进的Stieglitz重排反应制备苯胺

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

化学学报 2020年第8期78卷 758-762页

作者：罗潇焦宁北京大学药学院天然药物及仿生药物国家重点实验室北京100191

本工作使用简单易得的三氟乙酸酐作为活化试剂,拓展了Stieglitz重排反应的底物适用范围,发展了一种通过C-C键断裂由苯乙基羟胺制备芳基伯胺的方法.该反应条件较为温和且对官能团具有较好的兼容性.机理研究表明,反应经历了活性三氟乙酸... 详细信息

本工作使用简单易得的三氟乙酸酐作为活化试剂,拓展了Stieglitz重排反应的底物适用范围,发展了一种通过C-C键断裂由苯乙基羟胺制备芳基伯胺的方法.该反应条件较为温和且对官能团具有较好的兼容性.机理研究表明,反应经历了活性三氟乙酸酯中间体的原位生成,并通过C-C和N-O键的断裂实现芳基迁移的过程.

关键词： C—C键断裂 Stieglitz重排反应羟胺苯胺芳基迁移

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

氧气氧化铜催化的苯胺邻位叠氮化反应

化学学报 2019年第9期77卷 906-910页

作者：林凤闺蓉梁宇杰郦鑫耀宋颂焦宁北京大学药学院天然药物及仿生药物国家重点实验室北京100191 华东师范大学上海市绿色化学与化工过程绿色化重点实验室上海200062

叠氮取代的苯胺是有机合成中应用广泛的结构单元.通过C—H键活化策略来制备叠氮基苯胺衍生物往往需要使用当量的剧烈氧化剂,造成反应的整体原子经济性低,官能团耐受性差.本文使用廉价、绿色的氧气作为最终氧化剂,发展了高效的铜催化苯胺... 详细信息

叠氮取代的苯胺是有机合成中应用广泛的结构单元.通过C—H键活化策略来制备叠氮基苯胺衍生物往往需要使用当量的剧烈氧化剂,造成反应的整体原子经济性低,官能团耐受性差.本文使用廉价、绿色的氧气作为最终氧化剂,发展了高效的铜催化苯胺C—H键叠氮化的方法.该转化具有反应条件温和、区域选择性单一和官能团兼容性广等优点.

关键词：氧气苯胺叠氮化碳-氢键活化铜催化

Nitromethane-Enabled Fluorination of Styrenes and Arenes

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CCS Chemistry 2020年第6期2卷 566-575页

作者： Weijin Wang Tongyu Huo Xinyi Zhao Qixue Qin Yujie Liang Song Song Guosheng Liu Ning Jiao State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityBeijing 100191 State Key Laboratory of Pharmaceutical Biotechnology Nanjing UniversityNanjing 210023Jiangsu State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032

The electrophilic fluorination of unsaturated compounds provides a reliable approach to the generation of organofluorides,which are used widely in agrochemicals,pharmaceuticals,and other materials.Numerous active electrophilic fluorine reagents,such as the fluorine molecule(F_(2))or xenon difluoride(XeF_(2)),have been applied in fluorination.However,these reagents suffer from their hazardous,toxic,corrosive,and poor selective properties,and the relatively weak electrophilicity of Selectfluor or N-fluorobenzenesulfonimide(NFSI)usually limits their broad applications.Herein,we disclose nitromethane(MeNO_(2))as an efficient activator of Selectfluor and NFSI,as well as a stabilizer of carbocations.Therefore,the fluoro-azidation,fluoroamination,fluoroesterification of styrenes,and C–H fluorination of(hetero)arenes were well realized just by the facilitation of MeNO_(2).The mild reaction conditions and practicability made our current method a versatile protocol for accessing organofluorides.

关键词： fluoroazidation fluoroamination fluoroesterification electrophilic fluorination nitromethane

Rh-catalyzed Transient Directing Group Promoted C-H Amidation of Benzaldehydes Utilizing Dioxazolones

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2018年第3期36卷 213-216页

作者： Xiaoyang Wang Song Song Ning Jiao State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical Sciences Peking University Xue Yuan Rd. 38 Beijing 200192 China State Key Laboratory of Organometallic Chemistry Chinese Academy of Sciences Shanghai 200032 China

Transition-metal catalyzed C--H functionalization of benzaldehydes is of great interest in organic synthesis. Herein, we developed a transient directing group assisted amidation of benzaldehydes catalyzed by rhodium catalyst. With the employment of 10 mol% of 4-trifluoromethyl aniline, the in situ generated imine groups as the directing group efficiently enable this transformation. By using this protocol, a wide range of benzaldehydes were efficiently converted into the corresponding N-（2-formylphenyl）benzamides utilizing dioxazolones as the nitrogen source.

关键词： amidation benzaldehydes rhodium C--H functionalization transient directing group

Metal-Free 12-Catalyzed Highly Selective Dehydrogenative Coupling of Alcohols and Cyclohexenones

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2018年第3期36卷 233-240页

作者： Yu-Feng Liang Yizhi Yuan Tao Shen Song Song Ning Jiao State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical Sciences Peking University Xue Yuan Rd. 38 Beijing 100191 China State Key Laboratory of Elemento-Organic Chemistry Nankai University Weijin Road 94 Tianjin 300071 China

The l2 catalyzed highly selective oxidatve condensation of cydohexenones and alcohols for the synthesis of aryl atkyl ethers has been described. DMSO is employed as the mild terminal oxidant. This novel methodology offers a metal-free reaction condition, operational simplicity and broad substrate scope to afford valuable products from inexpensive reagents. Various meta-substituted aromatic ethers which are hardly synthesized from the reported methods requiring meta-substituted phenols, are efficiently prepared by the present protocol.

关键词： metal-free dehydrogenative coupling oxidation selectivity alcohols

亚硝酸钠为氮氧源构建呋咱氮氧化物及异噁唑类化合物

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

分子科学学报 2021年第1期37卷 85-94页

作者：晏子茜张立志宋颂焦宁北京大学药学院天然药物与仿生药物国家重点实验室北京100191

本文报道了一种构筑呋咱氮氧化物与异噁唑类化合物的新方法.以简单易得的苯乙酮类底物为原料,亚硝酸钠为氮氧源,在三氟甲磺酸酐和甲酸的活化下,合成了一系列呋咱氮氧化物.在同样的反应条件下,以苯乙酮和炔烃为原料,合成了一系列异噁唑... 详细信息

本文报道了一种构筑呋咱氮氧化物与异噁唑类化合物的新方法.以简单易得的苯乙酮类底物为原料,亚硝酸钠为氮氧源,在三氟甲磺酸酐和甲酸的活化下,合成了一系列呋咱氮氧化物.在同样的反应条件下,以苯乙酮和炔烃为原料,合成了一系列异噁唑类化合物.

关键词：呋咱氮氧化物异噁唑亚硝酸钠