Heterogeneous photocatalytic organic synthesis: state-of-the-art and future perspectives

Abstract

Heterogeneous photocatalytic systems have the potential to provide green organic synthesis routes for a number of industrially important chemicals. This review presents the latest achievements in this research field and compares them with traditional catalytic systems employed in organic synthesis.

Rose Bengal Immobilized on Supported Ionic‐Liquid‐like Phases: An Efficient Photocatalyst for Batch and Flow Processes

“…[2] The use of singlet oxygen does not produce any waste or residue, othert han the photocatalyst, at the end of the process. [4,5] However,i n some cases, this immobilization can lead to ar eduction of the photocatalytic efficiency throughq uenching of the excited states by the polymericm atrix or by shortening the lifetime of the reactive species. [4,5] However,i n some cases, this immobilization can lead to ar eduction of the photocatalytic efficiency throughq uenching of the excited states by the polymericm atrix or by shortening the lifetime of the reactive species.…”

Visible‐Light‐Mediated [4+2] Annulation of N‐Cyclobutylanilines with Alkynes Catalyzed by Self‐Doped Ti3+@TiO2

“…This shortcoming has certainly limited pure TiO 2 ’s applications, particularly in catalysis, as functional group compatibility and chemoselectivity under UV light is generally worse than lower-energy visible light. [3] A number of methods have been developed to narrow the band gap to the level that can be overcome by visible light. [4] Among them, doping proves very effective for narrowing the band gap by producing extra energy states within the band gap.…”

“…[10] Despite all the advantages possessed by TiO 2 , its use as photocatalyst in organic synthesis has remained limited. 3 Early work on TiO 2 ’s synthetic applications mostly focused on UV light irradiation. [3a], [11] Unfortunately, this work was often plagued by overoxidation and poor chemoselectivity, and thus later refocused on wastewater treatment.…”

“…3 Early work on TiO 2 ’s synthetic applications mostly focused on UV light irradiation. [3a], [11] Unfortunately, this work was often plagued by overoxidation and poor chemoselectivity, and thus later refocused on wastewater treatment. [12] Now armed with better understanding about how TiO 2 works in photocatalysis [13] and availability of a large number of visible-light-active TiO 2 [14] , we strongly felt that it might be time to revisit the topic of using TiO 2 to catalyze organic reactions particularly from the angle of visible light photocatalysis.…”

Effective separation of organic dyes using ionic liquids as green mobile phase and polyaniline-modified silica gel nanocomposite-based thin-layer chromatography

“…On the other hand, certain ionic liquids have attracted a lot of attention of researchers working in the areas of organic synthesis (Friedmann et al 2016), chromatography (Tabar Heydar et al 2013;Wang et al 2014;Yoshinaga et al 2014;Yoshinaga et al 2014;Yoshinaga et al 2014), biotechnology and environmental engineering (Jones et al 2002) mainly due to their unique combination of physicochemical properties such as very low volatility, non-flammability, high thermal and chemical stability and a large range of temperatures of their liquid state (Seddon 2003;Gutowski et al 2003). The ionic liquids have also become greatly useful in spectroscopy and electrochemistry (López-Lorente et al 2013;Lee et al 2014;Sun et al 2012;Ejigu et al 2011).…”