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。
A selenium-coordinated palladium(<scp>ii</scp>) <i>trans</i>-dichloride molecular rotor as a catalyst for site-selective annulation of 2-arylimidazo[1,2-<i>a</i>]pyridines
ΔG‡298K/ΔG‡350K values of 15.5 and 17.2 kcal mol−1 for a roughly 4.5 Å-long rotor. The molecular rotor showed excellent catalytic activity with reverse regioselectivity for annulation of 2-arylimidazo[1,2-a]pyridines (yields: ∼53–78%) with only 1.5 mol% catalyst loading.