Iron-Catalyzed C(sp<sup>2</sup>)–H Alkylation of Indolines and Benzo[<i>h</i>]quinoline with Unactivated Alkyl Chlorides through Chelation Assistance
作者:Rahul A. Jagtap、Pragnya Paramita Samal、C. P. Vinod、Sailaja Krishnamurty、Benudhar Punji
DOI:10.1021/acscatal.0c02030
日期:2020.7.2
Regioselective C–H bond alkylation of indolines and benzo[h]quinoline with a wide range of unactivated and highly demanded primary and secondary alkyl chlorides is accomplished using a low-cost iron catalyst. This reaction tolerates diverse functionalities, such as C(sp2)–Cl, fluoro, alkenyl, silyl, ether, thioether, pyrrolyl, and carbazolyl groups including cyclic and acyclic alkyls as well as alkyl-bearing
使用低成本的铁催化剂可完成二氢吲哚和苯并[ h ]喹啉的区域选择性C–H键烷基化反应,以及大量未活化且要求很高的伯和仲烷基氯。该反应可耐受多种官能团,例如C(sp 2)–Cl,氟,烯基,甲硅烷基,醚,硫醚,吡咯基和咔唑基,包括环状和非环状烷基以及带有烷基的脂肪醇和多环甾体部分。所证明的铁催化方案通过五元或六元金属环进行。有趣的是,C-7烷基化的二氢吲哚可以很容易地官能化为游离的NH吲哚啉/吲哚和色胺衍生物。详细的机械研究重点介绍了活性Fe(I)催化剂的参与和卤素原子通过单电子基机理转移的过程。氘标记和动力学分析表明,吲哚的C–H金属化是可能的营业额限制步骤。总体而言,实验和理论研究支持了烷基化反应的Fe(I)/ Fe(III)途径,该途径包括烷基氯的两步单电子氧化加成。