We report high‐performance I+/H2O2 catalysis for the oxidative or decarboxylative oxidative α‐azidation of carbonyl compounds by using sodium azide under biphasic neutral phase‐transfer conditions. To induce higher reactivity especially for the α‐azidation of 1,3‐dicarbonyl compounds, we designed a structurally compact isoindoline‐derived quaternary ammonium iodide catalyst bearing electron‐withdrawing
我们报告了在双相中性相转移条件下使用叠氮化钠对羰基化合物进行氧化或脱羧氧化α-叠氮化的高性能I + / H 2 O 2催化。为了诱导更高的反应活性,尤其是对于1,3-二羰基化合物的α-叠氮化,我们设计了结构紧凑的异吲哚啉衍生的带有吸电子基团的季碘化铵催化剂。I + / H 2 O 2的非生产性分解途径催化量可以通过使用催化量的自由基捕获剂来抑制。这种氧化偶合耐受各种官能团,可以很容易地应用于结构多样的复杂分子的后期α-叠氮化。此外,我们实现了1,3-二羰基化合物的对映选择性α-叠氮化,这是手性次碘酸盐催化剂与对映选择性分子间氧化偶联的第一个成功实例。
Mild α-Halogenation Reactions of 1,3-Dicarbonyl Compounds Catalyzed by Lewis Acids
作者:Dan Yang、Yi-Long Yan、Bob Lui
DOI:10.1021/jo026025t
日期:2002.10.1
Lewis acid Mg(ClO4)2, combined with NBS, in CH3CN or EtOAc provided mild and fast bromination of 1,3-dicarbonyl compounds. In particular, this protocol could be applied to the alpha-monobromination of alpha-unsubstituted beta-keto esters. Similar Lewis acid catalysis was also extended to the alpha-chlorination and iodination of 1,3-dicarbonyl compounds with NCS and NIS, respectively.
Photoredox-Catalyzed Oxidation of Anions for the Atom-Economical Hydro-, Amido-, and Dialkylation of Alkenes
作者:Katherine C. Forbes、Anne Marie Crooke、Yuri Lee、Masamu Kawada、Kian M. Shamskhou、Rachel A. Zhang、Jeffrey S. Cannon
DOI:10.1021/acs.joc.1c03055
日期:2022.3.4
method to generate free radical intermediates in organic synthesis. This report describes the use of photoredox catalysis to directly oxidize common nucleophilic anions to access electrophilic 1,3-dicarbonyl and amidyl radical intermediates. First, conjugate bases of 1,3-dicarbonyls were oxidized to neutral radical species for intramolecular hydro- and dialkylation of alkenes. This overall redox-neutral