Iodine-catalyzed regioselective sulfenylation of imidazoheterocycles in PEG<sub>400</sub>
作者:Marie-Aude Hiebel、Sabine Berteina-Raboin
DOI:10.1039/c4gc01462f
日期:——
An iodine-catalyzedsulfenylation of imidazo[1,2-a]-pyridines, -pyrimidines, and [1,2-b]pyridazines is herein described with various thiophenols using hydrogen peroxide as an oxidizing agent in PEG400. The method enabled the formation of 3-arylthioimidazoheterocycles in moderate to excellent yields under metal-free conditions. Several functional groups were well tolerated under our optimized conditions
本文描述了咪唑并[1,2- a ]-吡啶,-嘧啶和[1,2- b ]哒嗪的碘催化的亚磺酰基化,其中使用过氧化氢作为氧化剂在PEG 400中与各种硫酚一起使用。该方法能够在无金属条件下以中等至优异的产率形成3-芳基硫代咪唑并杂环。在我们优化的条件下,几个官能团的耐受性良好。
Iodine-Mediated Difunctionalization of Imidazopyridines with Sodium Sulfinates: Synthesis of Sulfones and Sulfides
作者:Yu-Jing Guo、Shuai Lu、Lu-Lu Tian、En-Ling Huang、Xin-Qi Hao、Xinju Zhu、Tian Shao、Mao-Ping Song
DOI:10.1021/acs.joc.7b02734
日期:2018.1.5
Novel iodine-induced sulfonylation and sulfenylation of imidazopyridines have been described using sodium sulfinates as the sulfur source. This strategy enables highly selective difunctionalization of imidazo[1,2-a]pyridine to access sulfones and sulfides in good yields. A wide range of substrates and functional groups were well-tolerated under optimized conditions. Moreover, control experiments have
已经描述了使用亚磺酸钠作为硫源的新的碘诱导的咪唑并吡啶的磺酰化和亚磺酰化。该策略能够使咪唑并[1,2- a ]吡啶高度选择性地进行双官能化,从而以高收率获得砜和硫化物。在最佳条件下,各种底物和官能团均具有良好的耐受性。此外,已经进行了对照实验,表明了反应机理中涉及的自由基途径。
Metal-Free Regioselective Alkylation of Imidazo[1,2-a]pyridines with N-Hydroxyphthalimide Esters under Organic Photoredox Catalysis
A visible-light-induced direct C–H alkylation of imidazo[1,2-a]pyridines has been developed. It proceeds at room temperature by employing inexpensive Eosin Y as a photocatalyst and alkyl N-hydroxyphthalimide (NHP) esters as alkylationreagents. A variety of NHP esters derived from aliphatic carboxylicacids (primary, secondary, and tertiary) were tolerated in this protocol, giving the corresponding
Metal-free benzoylation of imidazoheterocycles by oxidative decarboxylation of arylglyoxylic acids
作者:Sonam Jaspal、Vikki N. Shinde、Neha Meena、Dhananjay S. Nipate、Krishnan Rangan、Anil Kumar
DOI:10.1039/d0ob01842b
日期:——
A simple and straightforward approach has been realized for the direct benzoylation of imidazoheterocycles by oxidative decarboxylation of arylglyoxylic acids in the presence of K2S2O8 as an oxidant. Various functional groups were tolerated on both imidazoheterocycles and arylglyoxylic acids and a wide range of C5-benzoyl-imidazoheterocycles were obtained in good to high yields (50–84%). Radical trapping
在 K 2 S 2 O 8作为氧化剂的存在下,通过芳基乙醛酸的氧化脱羧,实现了一种简单直接的咪唑杂环直接苯甲酰化方法。咪唑杂环和芳基乙醛酸均耐受各种官能团,并且以良好至高产率(50-84%)获得了范围广泛的 C5-苯甲酰基-咪唑杂环。自由基捕获实验证实了自由基途径的参与。开发的协议适用于放大反应。
Electrochemical Oxidative Regioselective C–H Cyanation of Imidazo[1,2-<i>a</i>]pyridines
作者:Ting Cui、Yanling Zhan、Changhui Dai、Jun Lin、Ping Liu、Peipei Sun
DOI:10.1021/acs.joc.0c03026
日期:2021.11.19
Electrochemical oxidative regioselective C–H cyanation of imidazo[1,2-a]pyridines was developed using readily available TMSCN as the cyano source. The KH2PO4/K2HPO4 buffer was essential for this transformation. This protocol was compatible with a broad range of substituted imidazo[1,2-a]pyridines and provided the C3 cyanated products in moderate to excellent yields.
咪唑并[1,2- a ]吡啶的电化学氧化区域选择性C-H氰化是使用现成的TMSCN作为氰基源开发的。KH 2 PO 4 /K 2 HPO 4缓冲液对于这种转化是必不可少的。该方案与多种取代的咪唑并[1,2- a ]吡啶兼容,并以中等至优异的产率提供C3氰化产物。