2.7 C–C bond formation

The C–C bond formation is a versatile tool to generate various compounds; some examples are presented in Table 7, the products were generated in good to excellent

Table 7. Formation of C–C bond.

### Infrared Irradiation, an Excellent, Alternative Green Energy Source DOI: http://dx.doi.org/10.5772/intechopen.83805

yields, using NIR as the activating mode of reaction, with short reaction times in the presence of a catalyst, with or without the presence of a base.

Related to Table 7, several interesting commentaries are performed:

Balam-Villareal in 2016 informed about the formation of C-C bond by means of a Mizoroki-Heck cross-coupling reaction, Entry 3, employing new sulfur-containing palladacycles as catalyst and aryl iodides with electron-donating and electronwithdrawing groups. Thus the NIR strategy, has similar behavior that the MH in relation to the yields obtained, but the time reaction was diminished by three times.

Another example, corresponding to C-C bond formation, implicates the use of arylhydrazones containing the benzothiazole moiety as a contribution to the Mizoroki-Heck reaction, employing palladium ligands, Entries 4 and 5. The authors report that the reaction was performed using near infrared irradiation. The products were obtained from good to excellent yields, reducing the reaction time. In the same report, it was reported the use of this arylhydrazones in the Suzuki-Miyaura cross-coupling reaction with NIR as alternative source, water as solvent, diminishing the time of reaction, and the products were obtained with good yields.

Continuing with the Suzuki-Miyaura reaction type, the use of imidazolehydrazone as ligand was recently informed; the reaction was developed in short reaction times, improving the yields, all this result afforded by the use of NIR as the activating mode of reaction, with water as the solvent, offering a new ecological alternative to perform this kind of reaction, Entry 6.

## 2.8 Natural product extraction

Recently, several nucleophilic aromatic substitutions have been reported by Luna-Mora and coworkers; the authors inform about the preparation of N-(5-

comparative study among MH, NIR, US, MW, and the combination of NIR-US here is concluded that the best process was when the NIR-US process is employed

The C–C bond formation is a versatile tool to generate various compounds; some examples are presented in Table 7, the products were generated in good to excellent

E Reaction Ref. 1 [37]

2 [51]

3 [52]

4 [53]

5 [53]

6 [54]

amino-2-nitroanilines by means of a

amino-2-nitrophenyl) acetamides and 5-R<sup>1</sup>

2.7 C–C bond formation

Green Chemistry Applications

E = Entry, Ref = Reference.

Formation of C–C bond.

Table 7.

44

offering the best yields and short reaction times, Entry 5.

R1

Currently, it is well known that several methods are available to extract the secondary metabolites present in vegetable species, but recently, it was reported that the FIR can be also used [1] (Table 8).



NIR for 15 minutes was statically equal to the conventional thermal extraction,

The request, "Decade to Educate in the Sustainability," established by the UNESCO (2005–2014) satisfactorily evaluated in November 2014, at Aichi, Nagoya, Japan is attended in this chapter, in this sense by means of a green approach using the infrared irradiation as an alternative and efficient mode to activate an organic reaction in addition to conveniently performed extractions of secondary metabolites. Moreover, it is important to note that this green energy can be used in other areas as material engineering and other synthetic strategies as Suzuki-Miyaura or Mizoroki-Heck cross-coupling can use it to activate the reaction. Consequently, the infrared irradiation can extend their application to other organic

We would like to thank the Laboratorio de Estudios sobre Quimica Verde, L-122, Departamento de Ciencias Quimicas, Facultad de Estudios Superiores Cuautitlan, Universidad Nacional Autonoma de Mexico for financial affordings. R. Miranda

Acknowledges PAPIME-UNAM PE 209919 for financial support.

The authors declare no conflict of interest.

Penieres-Carrillo and coworkers currently have developed the acylation of aromatic amines and alcohols, by a comparative study among MH, US, IR, and IR-US, with preliminary results; the best process has been the simultaneous use of IR-US,

reflux during 3 h [78, 79].

transformations or disciplines.

Acknowledgements

Conflict of interest

47

4. Conclusions

with high yields and shorter reaction times [80].

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

Infrared Irradiation, an Excellent, Alternative Green Energy Source

#### Table 8.

Extraction of natural compounds.

Interesting and recent information corresponds to a study by Cheaib and coworkers, Entry 18, reporting the extraction comparing the solid/liquid extraction with infrared-assisted extraction. In this study, the FIR pomace extract, from apricot, gave the highest polyphenolic content, flavonoid, and tannin yields. In addition, the inhibitory activity study against gram-positive and gram-negative bacteria was performed, and the infrared pomace gave the highest activity in comparison with infrared kernel, solid-liquid pomace, and solid-liquid kernel.

More recently, Entry 19, Martínez and coworkers have reported the extraction of capsaicin and dihydrocapsaicin, from habanero pepper in a comparative study, the use of NIR as source of extraction with EtOH as solvent, showed the best yields, 43.88 and 29.44% for capsaicin, and dihydrocapsaicin, respectively. The effect of nonconventional energies was analyzed by means of SEM micrographs, resulting in an NIR-procedure with a higher number of intact particles in the cellular matrix, in comparison with nonirradiated material.

### 3. Unpublished results from our and other laboratories

The results showed in this section correspond to novel results, being important to note that they have been recently submitted for publication or are under writing.

A green contribution to produce SiO2–TiO2 catalyst is offered, using NIR in comparison with other nonconventional energy sources and mantle heating. According to the obtained results, the materials were produced in short time reaction employing water as solvent. The results, for NIR strategy, show that smaller crystal size (15.3 nm) and higher BET surface area were obtained (335.2 m<sup>2</sup> /g). In addition, the surface area obtained by mean NIR procedure, in comparison with other process, is due to that the water in the reaction was partially evaporated, affecting the hydrolysis process, but the pore and volume diameter was improved (4.33 nm and 0.363 cm3 /g, respectively) in comparison with the MH mode(2.77 nm and 0.290 cm<sup>3</sup> /g) [77].

Related to natural product extraction, Miranda et al. have achieved a wide study about the extraction of perezone, from roots of both Acourtia adnata and Acourtia platyphylla comparing various modes: MH, NIR, MW, US, and supercritical CO2. It is appropriated to comment that the yield obtained from the extraction with

Infrared Irradiation, an Excellent, Alternative Green Energy Source DOI: http://dx.doi.org/10.5772/intechopen.83805

NIR for 15 minutes was statically equal to the conventional thermal extraction, reflux during 3 h [78, 79].

Penieres-Carrillo and coworkers currently have developed the acylation of aromatic amines and alcohols, by a comparative study among MH, US, IR, and IR-US, with preliminary results; the best process has been the simultaneous use of IR-US, with high yields and shorter reaction times [80].
