Catalytic 1,2-Regioselective Dearomatization of N-Heteroaromatics via a Hydroboration
作者:Heng Liu、Maxim Khononov、Moris S. Eisen
DOI:10.1021/acscatal.8b00074
日期:2018.4.6
catalyzed highly 1,2-regioselective dearomatization of pyridines via a hydroboration process is reported herein. Twelve different kinds of meta- and para-substituted pyridines are applicable to this reaction, giving the corresponding N-boryl-1,2-dihydropyridine products in high yields. Other N-heteroaromatic compounds, such as benzo-fused N-heterocycles, pyrazines, pyrimidines, 1,3,5-triazine, and benzothiazole
甲基or和氢化物配合物(C 5 Me 5)2 ThMe 2和[(C 5 Me 5)2 Th(H)(μ-H)] 2通过氢硼化过程催化吡啶的高度1,2-区域选择性脱芳香化反应。在此报告。十二种间位和对位取代的吡啶适用于该反应,给出相应的N-硼基-1,2-二氢吡啶产物的收率高。还发现其他N-杂芳族化合物,例如苯并稠合的N-杂环,吡嗪,嘧啶,1,3,5-三嗪和苯并噻唑也具有高化学选择性的硼氢化。包括同位素效应研究在内的动力学表明,催化剂,吡啶和频哪醇硼烷的浓度具有一级依赖性,而脱芳香化的最终产物的释放是速率确定的步骤。在化学计量反应和动力学研究的基础上提出了一个合理的机制。
Atom-efficient regioselective 1,2-dearomatization of functionalized pyridines by an earth-abundant organolanthanide catalyst
作者:Alexander S. Dudnik、Victoria L. Weidner、Alessandro Motta、Massimiliano Delferro、Tobin J. Marks
DOI:10.1038/nchem.2087
日期:2014.12
synthesis. Dearomatization of pyridine derivatives is an important transformation to access a wide range of valuable nitrogenous natural products, pharmaceuticals and materials. Here, we report an efficient 1,2-regioselective organolanthanide-catalysed pyridine dearomatization process using pinacolborane, which is compatible with a broad range of pyridines and functional groups and employs equimolar
Regioselective 1,2-Dearomatization of Functionalized Azines by Organolanthanide Catalysts
申请人:Northwestern University
公开号:US20160159825A1
公开(公告)日:2016-06-09
A 1,2-regioselective organolanthanide-catalyzed azine dearomatization process using pinacolborane is disclosed.
揭示了一种使用缔合硼酸钙催化的1,2-区域选择性芳香烃脱芳构化过程。
Iron-Catalyzed 1,2-Selective Hydroboration of <i>N</i>-Heteroarenes
作者:Fanjun Zhang、Heng Song、Xuewen Zhuang、Chen-Ho Tung、Wenguang Wang
DOI:10.1021/jacs.7b11416
日期:2017.12.13
A N2-bridged diiron complex [Cp*(Ph2PC6H4S)Fe]2(μ-N2) (1) has been found to catalyze the hydroboration of N-heteroarenes with pinacolborane, giving N-borylated 1,2-reduced products with high regioselectivity. The catalysis is initiated by coordination of N-heteroarenes to the iron center, while the B-H bond cleavage is the rate-determining step.
While numerous organo(metallic)catalyst systems were documented for dearomative hydroboration of N‐aromatics, alkoxide base catalysts have not been disclosed thus far. Described herein is the first example of alkoxide‐catalyzed hydroboration of N‐heteroaromatics including pyridines, providing a broad range of reduced N‐heterocycles with high efficiency and selectivity. Mechanistic studies revealed