Formal [4+1] heteroannulative coupling of Knoevenagel adducts derived from 2-heteroaryl acetonitriles with isocyanides: subsequent Pd-catalyzed intramolecularN-arylation to 6-5-5-5-6 pentacyclic cores

Abstract

A concise and practical approach for expedient synthesis of substituted benzoxazolpyrrole, benzothiazolpyrrole and indolizine by three-component cascade annulative coupling of aldehyde, 2-hetaryl acetonitrile and isocyanide in the presence of 10...

Shedding Light on Benzo[d]pyrrolo[2,1-b]thiazole-3-carbonitrile Sensitizer-Based TiO2 Photocatalysts for Enhanced Hydrogen Generation

“…As seen in Figure b and Table , M–S plots were determined at a frequency of 1.0 kHz in a 0.5 M Na 2 SO 4 solution. The flat band potentials are −0.7, −0.8, and −1.0 V for TiO 2 –BP-3, TiO 2 –BP-2, and TiO 2 –BP-1, respectively, which closely interrelate to the band gap kinetics of the synthesized photocatalysts. ,,,,, …”

“…The flat band potentials are −0.7, −0.8, and −1.0 V for TiO 2 −BP-3, TiO 2 −BP-2, and TiO 2 −BP-1, respectively, which closely interrelate to the band gap kinetics of the synthesized photocatalysts. 10,12,13,24,26,27 3.11. Mechanistic Path for H 2 Generation.…”

“…All of the reagents and the solvent were charged into a 10 mL vial fitted with a magnetic stir bar under a nitrogen atmosphere and heated in a preheated oil bath at 80 °C while being stirred for 3 h. After cooling to room temperature, the crude reaction mixture was directly charged into a 100–200 mesh silica gel column and eluted with 10% ethyl acetate in hexane to obtain the desired compound BP-1 as a white solid (85.4 mg, 76% yield). Similarly, BP-2 and BP-3 were synthesized from 2-bromobenzaldehyde using tert -butyl isocyanide and cyclohexyl isocyanide, respectively . All of the synthesized dyes were fully characterized with 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectroscopy (HRMS).…”

“…Similarly, BP-2 and BP-3 were synthesized from 2-bromobenzaldehyde using tert-butyl isocyanide and cyclohexyl isocyanide, respectively. 24 All of the synthesized dyes were fully characterized with 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy and highresolution mass spectroscopy (HRMS). The 1 H and 13 C NMR spectra of the synthesized dyes are given in the Supporting Information (Figures S8−S10).…”

“…This result indicates that the BP-1 sensitizer has an excellent light-harvesting capability. Additionally, the theoretically calculated low-lying energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of TiO 2 –BP-1 clearly indicate the suitability of this catalyst for the enhanced production of hydrogen via water splitting; this production is stimulated by benzothiazole via intramolecular C–N and C–S functionalization bond formation and the substituent methoxy groups on the benzene ring. , Overall, the increased photocatalytic activity of these devices under simulated sunlight shows that BP derivatives have the potential to be useful photosensitizers in sustainable hydrogen generation applications.…”