REVISITING THE NUCLEOPHILICITY CONCEPT IN A COMPREHENSIVE BIOMASS VALORIZATION EXPERIMENT: FROM PAPAYA SEEDS TO THIOUREA MOTIFS

• Published in: Química Nova Vol. 42; no. 8; pp. 940 - 946
• Main Authors: Santos, Raquel, Viana, Gil, Moreira, Anderson, Nóbrega, Vitor, Silva, Vitor, Malta, Luiz Fernando, Aguiar, Lucia, Senra, Jaqueline
• Format: Journal Article
• Language: English
• Published: Sociedade Brasileira de Química 01.08.2019
• Subjects: Green Chemistry; hands-on learning; Organic Chemistry; third-year undergraduate students
• ISSN: 0100-4042; 1678-7064
• DOI: 10.21577/0100-4042.20170395

The recovery of waste materials with potential for synthetic transformations is a major field in science. However, just few experiments have been devoted to undergraduate students by exploring some consistent subjects in light of simple, natural resources. Nucleophilicity is a central subject in chemistry and there are significant synthetic models to exploit it in contrast to basicity. Here we present a laboratory experiment that utilizes hands-on research to be implemented in an organic chemistry lab by using benzyl isothiocyanate (BITC) from papaya seeds as raw material for the preparation of thioureas in a fast and visually indicative experiment. Subjects such as green chemistry, extraction methods, nucleophilicity, chromatography and NMR spectroscopy can be emphasized in order to implement a project-based approach. This experiment shows flexibility concerning the procedures and the use of biomass raw materials towards the reinforcement of a research-like experience and critical-thinking skills.