Pd(II)-Catalyzed Directing-Group-Aided C–H Arylation and Alkylation of Pyrene Core: Synthesis of C1,C2- and C1,C10-Disubstituted Pyrene Motifs

Abstract

We report the application of the Pd(II)-catalyzed, directing group-aided C-H arylation/alkylation tactics to functionalize pyrene core, especially, the relatively inaccessible C2 and K-region C10 positions of pyrene core and augmentation of the library of pyrene derivatives with C1,C2- and C1,C10-disubstituted pyrene motifs. The Pd(II)-catalyzed β-C-H arylation/alkylation of the C2-position of pyrene-1-carboxamide possessing 8-aminoquinoline directing group yielded various C1,C2-disubstituted pyrenes. Similarly, the Pd(II)-catalyzed selective γ-C-H arylation/alkylation of the C10-position of N-(pyren-1-yl)picolinamide possessing picolinamide directing group yielded various C1,C10-disubstituted pyrenes. Examples of C(9)-H arylation of pyrene-1-carboxamide and the removal of the directing group after the C-H arylation/alkylation reactions were also shown. The structures of representative pyrene derivatives were confirmed by the X-ray structure analysis. Given the importance of the pyrene derivatives in various fields of chemical sciences, this report is a contribution towards augmentation of the library of pyrene derivatives with C1,C2- and C1,C10-disubstituted pyrene amide motifs.

Phosphorus‐Directed Rhodium‐Catalyzed C−H Arylation of 1‐Pyrenylphosphines Selective at the K‐Region

“…[11] More recently, Babu et al described the selective arylation and alkylation in C2 and C10 positions of N-containing pyrene derivatives by palladium-catalyzed CÀ H functionalization using appropriate bidentate directing groups such as picolinamide and 8-quinoline carboxamide, respectively. [12] Yang et al developed a coppercatalyzed (O)P-directed CÀ H arylation of PAH using hypervalent aryl iodanes, [13] illustrated in a single example to occur for a pyrene derivative in γ-position of the (O)P-directing group (C9-H arylation in Kregion).…”

Structure‐Property Correlation of C10‐(H)‐Arylated‐N‐(pyren‐1‐yl)‐picolinamide Regioisomers towards Cu2+ and Fe3+ Sensing

“…Recently, some of us (Babu and co-workers) developed a Pd(II) catalyzed directing group aided CÀ H arylation and alkylation method to access new C(10)-arylated-N-(pyren-1-yl)-picolinamide derivatives. [43] In the present work, we have investigated the photophysical and sensing properties of these newly developed C10-(H)-Arylated-N-(pyren-1-yl)-picolinamides towards (1 a-2 b) various metal ions. [43] All compounds have a common structural framework consisting of a pyrene moiety connected through amide group (Py-NH-CO) to picoline at C-1 position and different aryl substitutions at C-10 position of pyrene (Figure 1).…”

“…[43] In the present work, we have investigated the photophysical and sensing properties of these newly developed C10-(H)-Arylated-N-(pyren-1-yl)-picolinamides towards (1 a-2 b) various metal ions. [43] All compounds have a common structural framework consisting of a pyrene moiety connected through amide group (Py-NH-CO) to picoline at C-1 position and different aryl substitutions at C-10 position of pyrene (Figure 1). [43] The amide group along with the picoline-nitrogen are expected to interact with metal cations thereby inducing significant variations in the spectral response of the pyrenyl picolinamides.…”

“…[43] All compounds have a common structural framework consisting of a pyrene moiety connected through amide group (Py-NH-CO) to picoline at C-1 position and different aryl substitutions at C-10 position of pyrene (Figure 1). [43] The amide group along with the picoline-nitrogen are expected to interact with metal cations thereby inducing significant variations in the spectral response of the pyrenyl picolinamides. Photophysical characterization of the C10-(H)-Arylated-N-(pyren-1-yl)-picolinamides (1 a-2 b) was performed by UV/Vis absorption and fluorescence spectroscopy.…”

“…Photophysical characterization of the C10-(H)-Arylated-N-(pyren-1-yl)-picolinamides (1 a-2 b) was performed by UV/Vis absorption and fluorescence spectroscopy. Based on important photophysical parameters such as molar extinction coefficients (ε) and fluorescence quantum yields (ϕ f ), these compounds were chosen among many compounds of similar type synthesized by Babu and co-workers [43] and categorized into two series: I and II. Series I consist of regioisomers 1 a and 1 b with meta-and para-methoxy phenylene substituents at the C-10 position of pyrene.…”