在此,我们描述了一种多功能的光催化策略,用于在n Bu 4 NI 存在下一步将氧化还原活性酯 (RAE) 脱羧转化为各种卤代烷、胺和烯烃。它是一种直接的方法,适用于一系列伯、仲、叔脂肪族羧酸衍生物和复杂天然产物的功能化。从机制上讲,电荷转移复合物 (CTC) 是通过 RAE 和n Bu 4之间的非共价相互作用形成的你。在光激发后,氨盐充当有效的电子供体和自由基重组的碘源。温和的反应条件使该方法可用于复杂天然产物的修饰和多功能的后续转化。
Copper-Catalyzed Decarboxylative Radical Silylation of Redox-Active Aliphatic Carboxylic Acid Derivatives
作者:Weichao Xue、Martin Oestreich
DOI:10.1002/anie.201706611
日期:2017.9.11
A decarboxylative silylation of aliphatic N‐hydroxyphthalimide (NHPI) esters using Si−B reagents as silicon pronucleophiles is reported. This C(sp3)−Si cross‐coupling is catalyzed by copper(I) and follows a radical mechanism, even with exclusion of light. Both primary and secondary alkyl groups couple effectively, whereas tertiary alkyl groups are probably too sterically hindered. The functional‐group
Visible-Light-Mediated Alkylation of Thiophenols via Electron Donor–Acceptor Complexes Formed between Two Reactants
作者:Yi-Ping Cai、Fang-Yuan Nie、Qin-Hua Song
DOI:10.1021/acs.joc.1c01433
日期:2021.9.3
A metal-free, photocatalyst-free, photochemical system was developed for the direct alkylation of thiophenols via electrondonor–acceptor (EDA) complexes (KEDA = 145 M–1) between two reactants, N-hydroxyphthalimide esters as acceptors and thiophenol anions as donors, in the presence of a tertiary amine. The EDA complexes in the reaction system have a broad range of visible-light absorption (400–650
开发了一种无金属、无光催化剂的光化学系统,用于通过两种反应物之间的电子供体 - 受体 (EDA) 配合物 ( K EDA = 145 M –1 )直接烷基化苯硫酚,N-羟基邻苯二甲酰亚胺酯作为受体和苯硫酚阴离子作为供体,在叔胺的存在下。反应体系中的 EDA 配合物具有广泛的可见光吸收范围(400-650 nm),可以在阳光下有效触发反应。
Selective Syntheses of <i>Z</i>-Alkenes via Photocatalyzed Decarboxylative Coupling of <i>N</i>-Hydroxyphthalimide Esters with Terminal Arylalkynes
A novel, efficient Z-alkene synthesis via photocatalyzed decarboxylative couplings between terminal aryl alkynes and alkyl N-hydroxyphthalimide (NHPI) esters, which are derived from aliphatic carboxylic acids, is described. A wide range of primary, secondary, and tertiary carboxylates as well as α-amino acid and α-oxyacid-derived esters were employed as suitable substrates. The mild reaction conditions
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
Decarboxylative Negishi Coupling of Redox‐Active Aliphatic Esters by Cobalt Catalysis
作者:Xu‐Ge Liu、Chu‐Jun Zhou、E. Lin、Xiang‐Lei Han、Shang‐Shi Zhang、Qingjiang Li、Honggen Wang
DOI:10.1002/anie.201806799
日期:2018.10
A cobalt‐catalyzed decarboxylative Negishi coupling reaction of redox‐active aliphatic esters with organozinc reagents was developed. The method enabled efficient alkyl–aryl, alkyl–alkenyl, and alkyl–alkynyl coupling reactions under mild reaction conditions with no external ligand or additive needed. The success of an in situ activation protocol and the facile synthesis of the drug molecule (±)‐preclamol