Photo-induced Decarboxylative Heck-Type Coupling of Unactivated Aliphatic Acids and Terminal Alkenes in the Absence of Sacrificial Hydrogen Acceptors
作者:Hui Cao、Heming Jiang、Hongyu Feng、Jeric Mun Chung Kwan、Xiaogang Liu、Jie Wu
DOI:10.1021/jacs.8b11218
日期:2018.11.28
boronates are among the most versatile building blocks that can be found in every sector of chemical science. We herein report a noble-metal-free method of accessing such olefins through a photo-induced decarboxylative Heck-type coupling using alkyl carboxylic acids, one of the most ubiquitous building blocks, as the feedstocks. This transformation was achieved in the absence of external oxidants through
1,2-二取代的烯烃,如乙烯基芳烃、乙烯基硅烷和乙烯基硼酸酯,是化学科学各个领域中最通用的结构单元。我们在此报告了一种无贵金属的方法,该方法使用烷基羧酸(最普遍的结构单元之一)作为原料,通过光诱导脱羧 Heck 型偶联获得此类烯烃。这种转变是在没有外部氧化剂的情况下通过有机光氧化还原催化剂和钴肟催化剂的协同组合实现的,H2 和 CO2 作为唯一的副产物。控制实验和 DFT 计算都支持基于自由基的机制,最终导致开发出脂肪族羧酸、丙烯酸酯和乙烯基芳烃的选择性三组分偶联。
Vinyl Sulfonium Salts as the Radical Acceptor for Metal-Free Decarboxylative Alkenylation
作者:Yu-Lan Zhang、Lei Yang、Jie Wu、Chunyin Zhu、Peng Wang
DOI:10.1021/acs.orglett.0c03074
日期:2020.10.2
Vinyl sulfonium salts typically act as an electrophilic Michael acceptor, thus initiating many tandem cyclization reactions. Herein, we disclosed the novel reactivity of vinyl sulfonium salts as a radical acceptor. Using redox-active ester as an alkyl radical precursor, metal-free decarboxylative alkenylation with vinyl sulfonium salts was realized using eosin Y as a photocatalyst. This process features
Irradiation-Induced Palladium-Catalyzed Decarboxylative Heck Reaction of Aliphatic <i>N</i>-(Acyloxy)phthalimides at Room Temperature
作者:Guang-Zu Wang、Rui Shang、Yao Fu
DOI:10.1021/acs.orglett.8b00023
日期:2018.2.2
It is reported that Pd(PPh3)2Cl2 in combination with 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos) under irradiation of blue LEDs efficiently catalyzes a decarboxylative Heck reaction of vinyl arenes and vinyl heteroarenes with aliphatic N-(acyloxy)phthalimides at roomtemperature. A broad scope of secondary, tertiary, and quaternary carboxylates, including α-amino acid derived esters
Photoredox catalysis enabled alkylation of alkenyl carboxylic acids with N-(acyloxy)phthalimide via dual decarboxylation
作者:Kun Xu、Zhoumei Tan、Haonan Zhang、Juanli Liu、Sheng Zhang、Zhiqiang Wang
DOI:10.1039/c7cc05910h
日期:——
ruthenium based photoredox catalyst in combination with substoichiometric amount of 1,4-diazabicyclo[2.2.2]octane (DABCO) efficiently catalyzed dual decarboxylative couplings between alkenyl carboxylic acids and N-(acyloxy)phthalimides derived from aliphatic carboxylic acids, delivering alkylated styrene derivatives in a high regio- and stereo- selective manner under mild reaction conditions. Various types
Iron-Catalyzed Vinylic C−H Alkylation with Alkyl Peroxides
作者:Liang Ge、Wujun Jian、Huan Zhou、Shaowei Chen、Changqing Ye、Fei Yu、Bo Qian、Yajun Li、Hongli Bao
DOI:10.1002/asia.201800534
日期:2018.9.4
are readily accessible from carboxylic acids, are utilized as general primary, secondary, and tertiary alkylating reagents for iron‐catalyzed vinylic C−H alkylation of vinyl arenes, dienes, and 1,3‐enynes. This transformation affords olefinic products in up to 98 % yield with high E/Z values. A broad range of functionalities, including carboxyl, boronic acid, methoxy, ester, amino, and halides, are