**2. Photoacetalization**

Aldehydes are prone to oxidation and amenable to attack by nucleophiles and can enolize, and as a result the dCHO functional group needs to be protected while carrying out the complex molecular architecture. Protection, de-protection, and reversing the reactivity or polarity through umpolung are the rudimentary strategies in the realm of organic synthesis. For these important tactics, recently VLPC has contributed a protection methodology, and the authors have protected the dCHO group as acetal [6]. The advantage of this protocol is that it does not employ the strong mineral, Lewis, and other acidic conditions; consequently the VLPC strategy presented by the chemists ranks as green technology. The protection was carried out using an organic dye, Eosin Y, with the use of [light-emitting diode (LED)] irradiation to promote the reaction under a milder condition. Several aldehydes were catalyzed in very high yields under household irradiation to the corresponding acetals (**Figure 3**).

**Figure 3.**

*Photocatalytic synthesis of acetals from aldehydes.*

## **3. Photo-oxidation of aldehydes**

The oxidation of organic compounds is being continuously explored since it is an important functional group modification, and the bench chemists are looking for environmental compatible and cost-effective methodologies for the same. By means of commercially affordable catalytic materials, several aldehydes were conveniently converted into their respective carboxylic acids where the <sup>1</sup> [O2] is used as oxidant catalyzed by Ru and Ir catalytic materials. The reaction is notably chemoselective and does not distress other oxidizable functional groups assembled within the molecule. Among the photosensitizers studied, Ir(dFppy)3 was the most efficient giving 99% yield of product from p-anisaldehyde. A wide range of aldehydes was studied with this catalyst and efficaciously oxidized under visible light [7] (**Figure 4**).

**Figure 4.** *Photocatalytic oxidation of aldehydes [7].*

*Visible-Light Photocatalysis of Aldehyde and Carbonyl Functionalities, an Innovative Domain DOI: http://dx.doi.org/10.5772/intechopen.92372*
