Polymers (Basel) 2019 Jul 4;11(7). Epub 2019 Jul 4.
Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia-Sede Bogotá, Carrera 30 No. 45-03, 7122 Carrera, Colombia.
Functionalization of tetrapropylcalixresorcinarene, tetrapentylcalixresorcinarene, tetranonylcalixresorcinarene, and tetra-(4-hydroxyphenyl)calixresorcinarene by means of aminomethylation reactions with the amino acids β-alanine and l-proline in the presence of aqueous formaldehyde was carried out. When β-alanine was used, the reaction products were tetrabenzoxazines. The reaction with tetra-(4-hydroxyphenyl)calixresorcinarene did not proceed under the experimental conditions; therefore, l-proline was used, and the corresponding tetra-Mannich base was regio- and diasteroselectively formed. Read More