Direct functionalization of C–H bonds has received significant attention in the synthetic chemistry community. In recent years, rapid and site-selective π-extension by C–H activation/functionalization has emerged as an ideal methodology for preparing organic π-materials. This issue focuses on π-extending C–H functionalization reactions directed toward new organic materials.
Graphical Abstract
Scheme 1: Cross-coupling polymerization of thiophene.
Scheme 2: Polymerization of bithiophene.
Scheme 3: Preparation of chlorobithiophenes.
Scheme 4: Polymerization of chlorobithiophenes.
Figure 1: Solubility tests of alternating copolymer 6 (1 mg of material dissolved in 1 mL of the solvent).
Figure 2: XRD measurement and prediction of the bilayer lamellar structure of polymer 6c. a) XRD analysis. b)...
Graphical Abstract
Scheme 1: Synthesis of BBFZPys through the Pd-catalyzed C–H/C–H coupling.
Scheme 2: Synthesis of 3a–c.
Scheme 3: Synthesis of 4a–c through oxidative coupling reaction.
Scheme 4: Synthesis of 6.
Figure 1: Absorption (dotted line) and fluorescence (solid line) spectra of 3, 4, and 6 measured as CHCl3 sol...
Figure 2: CD and CPL spectra of 3 measured as CHCl3 solutions (1.0 × 10−5 M) and in the solid states (dispers...
Figure 3: CD and CPL spectra of 4 and 6 measured as CHCl3 solutions (1.0 × 10−5 M) and in solid states (dispe...
Figure 4: ORTEP drawings of 4b and 4c with 50% thermal probability. Hydrogen atoms and solvent molecules are ...
Figure 5: Intramolecular stacking structures of 4b and 4c.
Graphical Abstract
Scheme 1: A high yielding, highly selective room-temperature direct arylation reaction between indole and iod...
Figure 1: 1H NMR (500 MHz, CDCl3) of (a) 5-iodo-1-octylindole monomer (b) PIn prepared according to condition...
Figure 2: MALDI–TOF MS of PIn, indicating octylindole repeat units with three different types of end groups. ...
Scheme 2: Commonly discussed mechanisms for C2 selective direct arylation, none containing radical intermedia...
Scheme 3: Proposed mechanism for palladium radical involved reaction between indole and iodobenzene.
Scheme 4: Radical trap effects on literature methods for the direct arylation at room temperature. A) From re...
Graphical Abstract
Figure 1: C–H functionalization of HBCs. (a) Perchlorinated HBC. (b) Borylated HBC substituted by 2,4,6-trime...
Figure 2: Synthesis of hexaborylated HBC 1. (a) Solvent screening of six-fold C–H borylation of unsubstituted...
Figure 3: The structure of 1 confirmed by X-ray crystallographic analysis. (a) ORTEP drawing of 1 with therma...
Figure 4: Photophysical properties of 1. (a) UV–vis absorption (solid lines) spectra, fluorescence (dotted li...
Graphical Abstract
Scheme 1: Synthetic methods of six-membered silacyclic compounds.
Scheme 2: Scope of dihydrosilanes. Conditions: a: conditions B (Table 1, entry 5); b: conditions A (Table 1, entry 3).
Scheme 3: Scope of diaryl ether and diaryl thioether derivatives. Conditions: a: conditions B (Table 1, entry 5); b:...
Scheme 4: Gram-scale Synthesis of 3a.
Scheme 5: Transformation of the amino groups in 3a.
Graphical Abstract
Figure 1: Examples of functional molecules based on π-extended phospholes.
Scheme 1: Syntheses of PAH-fused phospholes featuring a 7-hydroxybenzo[b]phosphole as a key intermediate.
Scheme 2: Synthesis of phosphole-fused ortho-teraryl compounds 7.
Scheme 3: Oxidative cyclization of phosphole-fused ortho-teraryl compounds 7 into triphenylene-fused phosphol...
Figure 2: ORTEP drawings of compound 8a (thermal ellipsoids set at 50% probability). a) top view; b) side vie...
Figure 3: UV–vis absorption (solid lines) and fluorescence (dashed lines) spectra of compounds 8a–c.
Graphical Abstract
Scheme 1: Direct C–H arylation of PAHs.
Scheme 2: Scope of aryliodonium salts. Reaction conditions: 1a (0.2 mmol), 2 (0.3 mmol) in DCE (1 mL) at 70 °...
Scheme 3: Scope of PAHs. Reaction conditions: 1 (0.2 mmol), 2a (0.3 mmol) in DCE (1 mL) at 70 °C under N2 for...
Scheme 4: Proposed catalytic cycle.
Figure 1: a) UV-visible absorption spectra of 4k, 4n and 4o in toluene (1 × 10−5 mol/L). b) Emission spectra ...
Graphical Abstract
Scheme 1: Projected synthetic routes for 3,6,13,16-tetrasubstituted tetrabenzo[a,d,j,m]coronenes.
Scheme 2: Reported syntheses of 2,7,12,17-tetrasubstituted tetrabenzo[a,d,j,m]coronenes.
Scheme 3: C–H tetraarylation of anthraquinone (1).
Scheme 4: C–H diarylation of 1,4-diarylanthraquinones 5.
Figure 1: Normalized UV–vis absorption spectra of 7aa, 7bb, and 7ba.
Figure 2: Effects of the concentration and the temperature on the 1H NMR spectra of 7aa.
Graphical Abstract
Figure 1: (a) Chemical structures of BODIPY (1) and dipyrromethane (2). (b) C–C bond forming alkynylations of...
Scheme 1: Synthesis of α-ethynyl-substituted BODIPY derivatives 3a and 4a.
Scheme 2: Synthesis of β-ethynyl-substituted BODIPY derivatives 5a and 5b and β,β'-diethynyl-substituted comp...
Figure 2: Top and front views of the crystal structures of (a) 4a and (b) 6b with 50% thermal ellipsoid proba...
Figure 3: Partial 1H NMR spectra of (a) 1a, (b) 3a, (c) 4a, (d) 5a, and (e) 6a recorded in CDCl3 at 298 K. As...
Figure 4: UV–vis absorption spectra of the BODIPY derivatives, (a) 1a (green), 3a (blue), 4a (red), and (b) 1a...
Figure 5: Fluorescence spectra of BODIPY derivatives. (a) 1a (green), 3a (blue), 4a (red) and (b) 1a (green), ...
Graphical Abstract
Figure 1: Chemical structures of a) oligorylene-bisimides, b) oligorylenes, c) bay-bridging oligorylenes, d) ...
Scheme 1: Synthesis of 2,5,10,13-tetrakis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)terrylene (TB4): (a) (B...
Figure 2: (Top) Single crystal X-ray structure of TB4. The thermal ellipsoids are scaled at 50% probability. ...
Figure 3: UV–vis absorption and fluorescence spectra of terrylene (black) and TB4 (red) in toluene. λex = 489...
Figure 4: MO diagrams of terrylene and TB4 based on calculations at the B3LYP/6-31G(d).
Scheme 2: Synthesis of 2,5,12,15-tetrakis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)quaterrylene (QB4): (a)...
Figure 5: UV–vis absorption spectrum of QB4 in toluene.
Figure 6: MO diagrams of terrylene and QB4 based on calculations at the B3LYP/6-31G(d).
Scheme 3: Suzuki–Miyaura cross-coupling reaction of TB4 with 2-bromomesitylene. (a) 2-bromomesitylene (8 equi...
Graphical Abstract
Figure 1: Structure of the target buckybowls 5a–c.
Scheme 1: Synthesis of dialkoxides 5a–c.
Scheme 2: Proposed mechanism of the formation of 5b and 5c.
Figure 2: Crystal structure of 5a. a) ORTEP drawing of the crystallographically independent unit with thermal...
Figure 3: a) Definition of POAV angle (φ). b) Side and c) top view of the molecular skeleton of 1. The double...
Figure 4: Crystal structure of 5b. a) ORTEP drawing of the crystallographically independent unit with thermal...
Figure 5: Crystal structure of 5c. a) ORTEP drawing of the crystallographically independent unit with thermal...
Figure 6: a) UV–vis spectra and b) emission spectra of 1 and dialkoxides 5a–c. For all the spectra, the conce...
Graphical Abstract
Scheme 1: Chemical structures of dicyclopenta-fused pyrene derivatives i–iii, peropyrene and the dicyclopenta...
Scheme 2: Synthetic route towards compound 1. a) B2pin2, dtbpy, [Ir(OMe)cod]2, cyclohexane, 70 °C, 20 h, 67%;...
Figure 1: High-resolution MALDI-TOF mass spectrum of 1. Inset: isotopic distribution compared to mass spectru...
Figure 2: Single-crystal X-ray structure of 1. (a) Top view and (b) side view of the (P,P) isomer. c) Crystal...
Figure 3: (a) UV–vis absorption spectra of precursor 5 and 1 in CH2Cl2 solution (10−5 M). Inset: photograph o...
Figure 4: Molecular orbitals of peropyrene derivative 6 and the dicyclopenta-fused peropyrene 1.
Graphical Abstract
Scheme 1: The previously reported family of the boomerang bipyrroles obtained by Pd-induced double C–H bond a...
Scheme 2: Synthesis and structures of α-free and α-oxygenated bipyrrole boomerangs. Reagents and conditions: ...
Figure 1: DFT-Optimized structures (B3LYP/6-31G(d,p)) of cNDA2O and cNMI3H.
Figure 2: Absorption and emission spectra of cNMI2H (top) and cNMI3H (bottom) measured in toluene, dichlorome...
Graphical Abstract
Figure 1: Target compounds.
Scheme 1: Synthesis of compounds 3.
Scheme 2: Synthesis of compound 4.
Figure 2: An optimized structure of 1a. a) Top view, b) side view, and c) labeling of the 1,3-dithiole rings.
Figure 3: Molecular orbitals of 1a.
Figure 4: Cyclic voltammograms of 1a,b, 2a, and 4 in PhCN/CS2 1:1 (v/v) solution.
Figure 5: Related compound 14.
Graphical Abstract
Scheme 1: a) Schematic depiction of the Jablonski diagram. b) Schematic representation of El-Sayed’s rule.
Figure 1: Top: literature examples of organic compounds showing RTP in the crystalline state (a) and in solut...
Scheme 2: Reaction conditions for para-bromobenzaldehyde 3: a) 1) 2-amino-2-methylpropan-1-ol, 4 Å MS, CH2Cl2...
Scheme 3: Reaction conditions: a) Br2, Fe powder, CHCl3, 0 °C, 4 h, 99%; b) KOH, KI, MeI, DMSO, 25 °C, 18 h, ...
Scheme 4: Reaction conditions: a) 1) NaH, THF, 0 °C, 30 min; 2) MeI, THF, 0 °C to 25 °C, 2 h, 99%; b) 1) MeOT...
Scheme 5: a) CuAAC reactions of azide-functionalized bromocarbaldehydes 3, 4 and 5 with terminal alkynes to t...
Figure 2: a) Normalized UV–vis absorption spectra of 3 (blue line), 34 (olive line), 4 (green line) and 38 (r...
Figure 3: a) Normalized UV–vis absorption spectra of 5 (blue line), 16 (green line), 42 (olive line) and 45 (...