deuterated architectures for various scientific applications. Traditionally, these deterium-labeled (hetero)aryl bromides are commonly prepared via multistep syntheses. Herein, we disclose a direct H/D exchange protocol for deuteration of (hetero)aryl bromides using Ag2CO3 as catalyst and D2O as deuterium source. This protocol is highly efficient, simply manipulated, and appliable for deuterium-labeling
氘标记的(杂)芳基溴是最广泛应用的基序之一,可实现重要的氘代体系结构以用于各种科学应用。传统上,这些氘标记的(杂)芳基溴化物通常是通过多步合成法制备的。在这里,我们公开了一种直接的H / D交换协议,用于使用Ag 2 CO 3作为催化剂和D 2对(杂)芳基溴进行氘化O作为氘源。该协议高效,简单易操作,适用于55种以上(杂)芳基溴的氘标记,包括生物活性药物样分子和功能材料的关键中间体。另外,该方法显示出与现有过渡金属催化的HIE过程截然不同的位点选择性,从而一步完成了多氘代(杂)芳基溴化物。
products. Final phase: Deficit of Mg(Ar)2 hinders formation of bis(π-arene)chromium complexes. “Ph2CrCl(thf)x” forms an equilibrium in THF solution with 3-thf3 and PhCrCl2(thf)x (1-Cl). During heating of a solution of 3-thf3, CrCl3(thf)3, and H2O (3:1:1) in THF o-metalation of a phenyl group leads to formation of mixed-valent tetranuclear [Ph4Cr4(μ4-OH)(μ-Cl)2(μ3-Cl)(μ3-C6H4)(thf)4] (4-Cr4) besides biphenyl
一个世纪前,Franz Hein于 1919 年 1 月首次发表论文,开始了备受推崇的芳基铬化学。根据Hein的方案,双(π-芳烃)铬化合物的形成是在 (Ar) 3型纯底物上进行的– n CrCl n (L) x ( n = 0, 1, 2; Ar = Ph, C 6 D 5 , p -FC 6 H 4 , L = 中性Lewis具有不同碱基强度和齿数的碱基)作为无卤化镁条件下的模型化合物。苯基的 σ-π 转移的三个主要合成阶段已被识别和模拟: 初始阶段(MgPh 2过量):Ph 3 Cr(thf) 3 ·0.25 dx·( 3-thf 3 , dx = 1, 4-二恶烷)在 C 6 D 6中可逆地消除四氢呋喃 (THF) ,产生蓝绿色 [Ph 3 Cr(thf) 2 ] ( 3-thf 2 ),在 5 °C 以上不可逆反应生成黑褐色联苯溶液、苯和“(η 6 -Ph 2 )CrI(μ-η
Cyclic Diaryl λ<sup>3</sup>‐Bromanes as a Precursor for Regiodivergent Alkynylation Reactions
作者:Maxime De Abreu、Torben Rogge、Matteo Lanzi、Tomas J. Saiegh、Kendall N. Houk、Joanna Wencel‐Delord
DOI:10.1002/anie.202319960
日期:2024.4.15
Regiodivergent reactions are a fascinating tool to rapidly access molecular diversity. Herein we reported the complemental character of hypervalent bromines, as aryne precursors and their behavior under transition metal-catalyzed reactions to furnish both ortho- and meta-substituted alkynylation products. Mechanistic and computational studies show how these selectivities are controlled.