Nucleophilic (Radio)Fluorination of Redox-Active Esters via Radical-Polar Crossover Enabled by Photoredox Catalysis
作者:Eric W. Webb、John B. Park、Erin L. Cole、David J. Donnelly、Samuel J. Bonacorsi、William R. Ewing、Abigail G. Doyle
DOI:10.1021/jacs.0c03125
日期:2020.5.20
redox-neutral method for nucleophilicfluorination of N-hydroxyphthalimide esters using an Ir photocatalyst under visible light irradiation. The method provides access to a broad range of aliphatic fluorides, including primary, secondary, and tertiary benzylic fluorides as well as unactivated tertiary fluorides, that are typically inaccessible by nucleophilicfluorination due to competing elimination
我们报告了在可见光照射下使用 Ir 光催化剂对 N-羟基邻苯二甲酰亚胺酯进行亲核氟化的氧化还原中性方法。该方法提供了获得广泛的脂肪族氟化物的途径,包括伯、仲和叔苄基氟化物以及未活化的叔氟化物,由于竞争消除,这些氟化物通常无法通过亲核氟化获得。此外,我们表明脱羧氟化条件很容易适应 [18F]KF 的放射性氟化。我们建议反应通过 Ir 催化剂和氧化还原活性酯底物之间的两次电子转移进行,以提供碳阳离子中间体,随后被氟化物捕获。
Direct monofluoromethylation of O-, S-, N-, and P-nucleophiles with PhSO(NTs)CH<sub>2</sub>F: the accelerating effect of α-fluorine substitution
作者:Xiao Shen、Min Zhou、Chuanfa Ni、Wei Zhang、Jinbo Hu
DOI:10.1039/c3sc51831k
日期:——
An efficient and direct monofluoromethylation of O-, S-, N-, and P-nucleophiles with PhSO(NTs)CH2F 1 has been developed. In contrast to the previously known detrimental effect of α-fluorine substitution on SN2 reactions, the current monofluoromethylation is accelerated by the α-fluorine substitution. Based on a mechanistic study, a new reactivity of sulfoximine (as a radical monofluoromethylation reagent) is disclosed.
<scp>Monofluoromethyl‐Substituted</scp>
Sulfonium Ylides: Preparation,
<scp>Structure‐Reactivity</scp>
Study and Substrate Scope
<sup>†</sup>
作者:Xin Hong、Yafei Liu、Long Lu、Qilong Shen
DOI:10.1002/cjoc.202000206
日期:2020.11
Structure‐reactivity study of a family of electrophilic monofluoromethylating reagents based on sulfonium ylide skeleton with different steric hindrance and electron‐withdrawing properties was described. These studies led us to discover two highly reactive reagents 3 with a cyclic malonate backbone and 6 with an electron‐poor 1,1,1,5,5,5‐hexafluoropentane‐2,4‐dione backbone. The high reactivity of reagent
Continuous Heterogeneous Photocatalysis in Serial Micro-Batch Reactors
作者:Bartholomäus Pieber、Menny Shalom、Markus Antonietti、Peter H. Seeberger、Kerry Gilmore
DOI:10.1002/anie.201712568
日期:2018.7.26
leaching catalysts, and heterogeneous photocatalysts are commonly employed in batch processes but are ill‐suited for continuous‐flow chemistry. Heterogeneous catalysts for thermal reactions are typically used in packed‐bed reactors, which cannot be penetrated by light and thus are not suitable for photocatalytic reactions involving solids. We demonstrate that serial micro‐batch reactors (SMBRs) allow
Fluorodecarboxylation for the Synthesis of Trifluoromethyl Aryl Ethers
作者:Qing-Wei Zhang、Andrew T. Brusoe、Vincent Mascitti、Kevin D. Hesp、David C. Blakemore、Jeffrey T. Kohrt、John F. Hartwig
DOI:10.1002/anie.201604793
日期:2016.8.8
The synthesis of mono‐, di‐, and trifluoromethyl aryl ethers by fluorodecarboxylation of the corresponding carboxylic acids is reported. AgF2 induces decarboxylation of aryloxydifluoroacetic acids, and AgF, either generated in situ or added separately, serves as a source of fluorine to generate the fluorodecarboxylation products. The addition of 2,6‐difluoropyridine increased the reactivity of AgF2