1. Introduction

Since the born (early 1990s) of the paradigm of the green chemistry (GC), it has acquired its up-to-date position as a scientific discipline preventing pollution and consequently contributing to the sustainable development (SD) [1]. In this sense, it is important to keep in mind the request of the United Nations Educational, Scientific and Cultural Organization (UNESCO) performed by the establishment of the Decade to Educate in the Sustainability (DES), 2005–2014, satisfactorily evaluated in November 2014 at Aichi, Nagoya, Japan. In this sense, the UNESCO desire to improve the quality of education (teaching researching and informing) at all levels, transforming the society by the reorientation of the education adopting the sustainable development aims [2, 3].

Consequently, many educational institutions in all levels, around the world, have assumed the GC protocol as an efficient pathway to contribute within the SD using and implementing innovative technologies.

In recent years, scientists around the world have implemented strategies to avoid the use of fossil resources; in this regard, it is convenient to note that between the GC-protocol, the six principles (energy requirements should be more recognized for their environmental and economic impacts, and they must be minimized) [4, 5] are well recognized [6] being important to highlight that several approaches to reduce the energetic consumption have been developed in order to diminish the dependence of fossil resources: the use of microwave irradiations (MW), ultrasound (US), mechanical milling (MM), photochemical (PC), electrochemical (EC), all of them

Figure 1. Infrared irradiation zones.

well recognized by the GC [7]. More recently, infrared irradiation (IR) has emerged as another excellent activating source into the green chemistry efforts [1, 7].

The infrared irradiation has been already perceived by the scientific community for the convenient promotion of organic transformations, this in addition to its employment to perform efficient natural product extractions, among others process.

Regarding the last commentaries, it results appropriated to establish the goal of this chapter: provide after a profound search in the literature, the actual status concerned to the employment of the infrared irradiation as an alternative mode to activate chemical reactions in addition to demonstrate its invaluable use to perform conveniently the extraction of interesting secondary metabolites.

On the other hand, taking as supportive reference the electromagnetic spectrum, the infrared region is divided into three zones, Figure 1. The shortwave or nearinfrared zone has band spans from 0.76 to 2 μm (NIR); the middle or medium infrared zone, with band spans from 2 to 4 μm (MIR); and the zone of long wave or far infrared with band spans from 4 to 1000 μm (FIR).

2.2 Nucleophilic additions

Knoevenagel condensation reactions.

E = Entry, Ref = Reference.

Table 1.

of ethanol, Entry 9.

37

2.3 Related macrocycles-benzyl oligomers

2.4 Multicomponent reaction

MIR and MW, both processes show similar yields, Table 3.

Several nucleophilic additions to various carbonylic substrates are confined in Table 2; consequently different products were obtained: heterocycles, Schiff bases, and the addition of a set of sulfur derivatives or the indolyl moiety to perezone, a natural product and its synthetic analog, Entry 10; it is important to note that the obtained indolyl molecules showed good activity against breast cancer cells. In these processes, the MIR was employed to promote the reaction; in some cases, Co doped with ZnS nanoparticles or TAFF were used as catalyst. The reactions, in general, proceed with good to excellent yields. Also, a green procedure to obtain a set of five coumarins, was developed, comparing different activating modes, MW, NIR, US, MM, and mantle heating (MH), in the presence or absence

E Reaction Ref. 1 [10]

Infrared Irradiation, an Excellent, Alternative Green Energy Source

DOI: http://dx.doi.org/10.5772/intechopen.83805

2 [11]

3 [12]

Various related macrocycles or benzyl oligomers were produced in the presence of TAFF as catalyst, in absence of solvent, considering a comparative study between

The multicomponent reaction implicates a very important and versatile strategy

to generate an enormously number of reaction protocols to produce important molecules. In this sense, MIR and NIR have been usefully employed as activating reaction modes, to promote molecules related to the multicomponent protocols of

It is worth noting that the NIR offers important advantages to carry out a reaction: due to its immediate response time, because it is efficiently used by convection, in addition to the longer life time of the tungsten-halogen filament [1, 8].
