Perfluoroalkyl Cobaloximes: Preparation Using Hypervalent Iodine Reagents, Molecular Structures, Thermal and Photochemical Reactivity
作者:Phil Liebing、Florian Oehler、Mona Wagner、Pascal F. Tripet、Antonio Togni
DOI:10.1021/acs.organomet.7b00892
日期:2018.2.26
bond is very resistant against photolysis, but the ligand L is readily exchanged by MeOH upon exposure to blue light. In the complexes with longer RF chains, the Co–C bond is more readily cleaved, and the product distribution depends strongly on the presence of O2. Thus, the alkane RFH is the main product under exclusion of O2, while a fluorinated methyl ester and HF are formed in a methanol solution
用全氟烷基碘试剂处理钴酸肟(II),[Co(Hdmg)2(L)2 ](Hdmg =二甲基乙二肟酸酯,L =中性配体)导致形成全氟烷基钴肟(III),[CoR F(Hdmg)2(L)](R F = CF 3,C 2 F 5,n -C 3 F 7,CF 2 CF 2 Ph; L = Py,NH 3,MeNH 2,PhNH 2,MeOH)。从醋酸钴(II)四水合物开始,合成方案可以显着简化为一锅法。产品已通过NMR,IR和UV / Vis光谱以及单晶X射线衍射进行了充分表征,并对热和光化学反应性进行了研究。根据在晶体中钴-L距离处,反式中的R影响˚F -配体可以评价为C 2 ˚F 5 - ≈ Ñ -C 3 ˚F 7 -
Enantioselective Copper-Catalyzed Fukuyama Indole Synthesis from 2-Vinylphenyl Isocyanides
作者:Till Drennhaus、Dirk Leifert、Jessika Lammert、Jan Philipp Drennhaus、Klaus Bergander、Constantin G. Daniliuc、Armido Studer
DOI:10.1021/jacs.3c01667
日期:2023.4.19
Enantioenriched chiral indoles are of high interest for the pharmaceutical and agrochemical industries. Herein, we present an asymmetric Fukuyama indolesynthesis through a mild and efficient radical cascade reaction to access 2-fluoroalkylated 3-(α-cyanobenzylated) indoles by stereochemical control with a chiral copper-bisoxazoline complex using 2-vinylphenyl arylisocyanides as radical acceptors and
对映体富集的手性吲哚引起了制药和农用化学工业的高度关注。在此,我们提出了一种不对称福山吲哚合成方法,通过温和有效的自由基级联反应,通过手性铜-双恶唑啉络合物的立体化学控制,使用2-乙烯基苯基芳基异氰化物作为自由基受体和氟烷基,获得2-氟烷基化的3-(α-氰基苄基化)吲哚。碘化物作为 C-自由基前体。异腈部分的自由基加成、5 -exo -trig 环化和 Cu 催化的立体选择性氰化为目标吲哚提供了优异的对映选择性和良好的产率。由于需要区分的两个芳基取代基具有相似的电子和空间性质,氰基二芳基甲烷立体中心的对映选择性构建极具挑战性。机理研究揭示了负非线性效应,允许提出一个模型来解释立体化学结果。证明了对映体富集的 3-(α-氰基苄基化)吲哚作为手性色胺、吲哚-3-乙酸衍生物和三芳基甲烷的中心的可扩展性和潜在用途,并公开了天然产物类似物的正式合成。
Cobalt‐Catalyzed Allylic Defluorinative Cross‐Electrophile Coupling between 1,1‐Difluoroalkyl Halides and α‐Trifluoromethyl Styrenes
作者:Haiyan Dong、Zhiyang Lin、Chuan Wang
DOI:10.1002/adsc.202300171
日期:——
In this protocol, we apply reductive cobalt catalysis in the allylic defluorinative cross-electrophile coupling reactionbetween 1,1-difluoroalkyl halides and α-trifluoromethyl styrenes. This reaction features broad substrate scope (39 examples), good tolerance of various functionalities, and circumvention of pregenerating organometallics, offering a general synthetic route to prepare diverse organofluorines
Nickel/Photo-Cocatalyzed Three-Component Alkyl-Acylation of Aryl-Activated Alkenes
作者:Pei Fan、Zhe Chen、Chuan Wang
DOI:10.1021/acs.orglett.3c03669
日期:2023.12.15
with aldehydes and electron-withdrawing-group-activated alkyl bromides, providing straightforward access to various ketones under mild and ligand-free conditions. The photocatalyst TBADT plays a dual role in activating the acyl C–H bond of aldehydes via hydrogen atom transfer and reducing the C–Br bond of alkyl bromides via single-electron transfer. While the terminal C–C bond is forged through polarity-matched
Copper(0)-mediated fluoroalkylation of iodobenzene with 2-bromo-1,1,2,2-tetrafluoroethyl compounds: Investigation on the influence of R substituent on the reactivity of RCF2Cu species
作者:Jieming Zhu、Chuanfa Ni、Bing Gao、Jinbo Hu
DOI:10.1016/j.jfluchem.2014.08.011
日期:2015.3
We have made a systematic investigation on the copper(0)-mediated tetrafluoroethylenation of iodobenzene with structurally diverse 2-bromo-1,1,2,2-tetrafluoroethyl compounds. A comparison of this reaction with 1,2,2-trifluoro-1-phenylethylation and the known functionalized difluoroalkylation demonstrates that the substituent R of alpha,alpha-difluoroalkyl copper species RCF2Cu plays a crucial role on their reactivity, which is believed to be useful for the development of new fluoroalkylation reactions under the promotion of transition metals. (C) 2014 Elsevier B.V. All rights reserved.