Palladium‐Catalyzed CH Fluorosilylation of 2‐Phenylpyridines: Synthesis of Silafluorene Equivalents

Abstract

Treatment of 2‐phenylpyridines with amino(1,3,2‐dioxaborolan‐2‐yl)diphenylsilane produced fluorosilylated 2‐phenylpyridines in good to excellent yields under palladium catalysis. This reaction is the first example of CH fluorosilylation. Single‐crystal X‐ray structure analysis revealed a Lewis acid–base interaction between the silicon and nitrogen atoms, and the obtained fluorosilylated products are silafluorene equivalents. The fluorosilylated products showed stronger fluorescence than the corresponding silafluorene derivative.

Palladium‐Catalyzed Construction of Heteroatom‐Containing π‐Conjugated Systems by Intramolecular Oxidative CH/CH Coupling Reaction

“…There are many recent reports of direct CÀHt ransformations, and several research groups have reported the synthesis of organic functional molecules using CÀHb ond transformations. [4] Twoother methods synthesize ladder-type p-conjugated molecules containing heteroatoms by either intramolecular cross-coupling reactions between CÀHa nd CÀOTf bonds (Figure 2c) [5] or intramolecular [6] and intermolecular [7] coupling reactions between CÀHa nd heteroatomÀHb onds ( Figure 2d).…”

Iridium‐Catalyzed Regioselective Silylation of Aromatic and Benzylic CH Bonds Directed by a Secondary Amine

“…In recent years, a variety of directing groups have been used to control the regioselectivity of CH bond silylation 8. 9 For example, imine,8a,e oxazoline,8c,i pyridine,8d,f,i,j, 9a,b pyrazole,8d,g and tertiary amine8d functionalities have been used as directing groups for the silylation of aromatic and benzylic CH bonds with trialkylsilanes. However, these directing groups are usually undesired in the final product, and multiple chemical transformations are needed to install and remove them.…”