An efficient method for the construction of dibenzo[b,d]azepines containing two distinct stereogenic elements in a highly diastereoselective fashion is described. The key of the [5 + 2] reaction is to form a π-allylpalladium species through sequential C–H activation and regiospecific migratory insertion of the diene. This observation contrasts with the behavior of 1,2-alkenes that generally underwent
sequential borane‐mediated C(sp2)−H borylation and intramolecular N‐demethylation. The conveniently in situ generated Piers’ borane from a borinic acid reacts with a series of N,N‐dimethyl‐1,1′‐biphenyl‐2‐amines in the presence of PhSiH3 to afford six‐membered amine‐borane adducts bearing a C(sp2)−B bond at the C2′‐position. These species undergo an intramolecular N‐demethylation with a B(C6F5)3 catalyst to
本文描述了通过连续的硼烷介导的C(sp 2)-H硼化和分子内N-去甲基化从1,1'-联苯胺获得BN-多芳族化合物的空前途径。在PhSiH 3存在下,由硼酸方便地就地生成的Piers'硼烷与一系列N,N-二甲基-1,1'-联苯-2-胺反应,得到六元胺-硼烷加合物在C2'位置的C(sp 2)-B键。这些物种通过B(C 6 F 5)3进行分子内N-去甲基化提供多芳族化合物的BN-等排体的催化剂。根据计算研究,提出了逐步的离子途径。所产生的BN-杂芳烃的光物理特征表明它们与全碳类似物具有显着差异。
Synthesis of Axially Chiral Biaryl‐2‐amines by Pd
<sup>II</sup>
‐Catalyzed Free‐Amine‐Directed Atroposelective C−H Olefination
作者:Bei‐Bei Zhan、Lei Wang、Jun Luo、Xu‐Feng Lin、Bing‐Feng Shi
DOI:10.1002/anie.201915674
日期:2020.2.24
A simple and ubiquitously present group, free amine, is used as a directing group to synthesize axially chiral biaryl compounds by PdII -catalyzed atroposelective C-H olefination. A broad range of axially chiral biaryl-2-amines can be obtained in good yields with high enantioselectivities (up to 97 % ee). Chiral spiro phosphoricacid (SPA) proved to be an efficient ligand and the loading could be reduced
“Transition-Metal-Free” Synthesis of Carbazoles by Photostimulated Reactions of 2′-Halo[1,1′-biphenyl]-2-amines
作者:Walter D. Guerra、Roberto A. Rossi、Adriana B. Pierini、Silvia M. Barolo
DOI:10.1021/jo5024393
日期:2015.1.16
and simple protocol for the preparation of a series of 9H-carbazoles by photostimulatedSRN1 substitution reactions is presented. Substituted 9H-carbazoles were synthesized in low to excellent yields (up to 96%) through an intramolecular C–N bond formation of 2′-halo[1,1′-biphenyl]-2-amines by the photoinitiated SRN1mechanism under mild and “transition-metal-free” conditions. The biphenylamines used