Environmentally Friendly and Regioselective One-Pot Synthesis of Imines and Oxazolidines Serinol Derivatives and Their Use for Rubber Cross-Linking

Abstract

High-yield regioselective synthesis of imines and oxazolidines derivatives of 2-amino-1,3-propandiol (serinol) was achieved by performing the reaction with aldehydes and ketones, in the absence of solvents and catalysts. Only imines were obtained when the carbonyl compound was aromatic and/or sterically hindered and when conjugated double bonds were formed. 1,3-Oxazolidines were specifically obtained with either aldehydes or ketones with limited steric hindrance. The "green" reaction conditions here adopted for the synthesis of these classes of derivatives are not due to the structural and functional peculiarity of the serinol as a reactant and can also be extended to lipophilic amines with the same good results in terms of yield and selectivity. A revision of the mechanism typically accepted in the presence of solvent and catalysis is proposed, and the quantum mechanics calculations applied to some derivatives are in good agreement with the proposed rationalizations of the selectivity observed. Serinol itself and the imine and oxazolidine derivatives were used, in place of guanidine, as accelerators in compounds based on diene rubbers and silica, suitable for application in tire treads with low environmental impact. Efficient sulfur-based cross-linking and composites with a low dissipation of energy were obtained. The oxazolidine and imine appear to act as protective groups of the serinol primary amine. This work paves the way for the selective synthesis of biosourced families of chemicals, which could be used for large-scale applications, such as the one in rubber compounds, replacing toxic oil-based chemicals.

CO2-Derived Methylene Oxazolidinone: A Platform Building Block for Functionalizing Ethylene–Vinyl Alcohol Copolymers

“…1,2-Amino alcohols exhibit a large variety of applications in chemical and pharmaceutical industries. In particular, their ability to condense with aldehydes is well-documented and gives access to 1,3-oxazolidines, , that is, heterocyclic structures present in several biologically active compounds . These pH-sensitive molecules can be seen as cyclic acetal analogues with one oxygen atom replaced by nitrogen and notably served for the reversible protection of 1,2-amino alcohols. − In the light of these considerations, the conversion of the 1,2-amino alcohols of P­(E- co -VOH- co -AMBO) into oxazolidines appeared as a method of choice for the selective and reversible post-modification of these amino-containing EVOH derivatives (Scheme ).…”

“…1,2-Amino alcohols exhibit a large variety of applications in chemical and pharmaceutical industries. In particular, their ability to condense with aldehydes is well-documented and gives access to 1,3-oxazolidines, 67,68 that is, heterocyclic structures present in several biologically active compounds. 69 These pH-sensitive molecules can be seen as cyclic acetal analogues with one oxygen atom replaced by nitrogen and notably served for the reversible protection of 1,2-amino alcohols.…”

BiosourcedJanusMolecules as Silica Coupling Agents in Elastomer Composites for Tires with Lower Environmental Impact

“…Crude rubber composites (5 g) were placed in the rheometer. As done in previous studies, for example, in ref , a first strain sweep (0.1–25% strain amplitude) was performed at 50 °C on noncross-linked samples, to cancel the thermo-mechanical history of the rubber composite. Then, the sample was kept at 50 °C for 10 min and subjected to another strain sweep at 50 °C.…”

Crystal structure of hexasodium tetraserinolium paratungstate B decahydrate, [Na6{(CH2OH)2CHNH3}4][W12O40(OH)2]·10H2O

“…We are expanding the class of hybrid paratungstates by using serinol (C 3 H 9 NO 2 ; 2-amino-1,3-propandiol), which has not previously been used in its protonated form as a counter-cation for paratungstates and can coordinate to metal cations in different ways via its -NH 2 or HOCH 2 -groups and thus influences both the structure and the properties of the compound significantly (Sifaki et al, 2021). Serinol is a very stable, readily watersoluble, non-toxic, odorless, biodegradable compound that is used as a versatile starting material in organic synthesis and as an additive for material applications, such as composite materials (Barbera et al, 2020;Andreessen & Steinbu ¨chel, 2011). In POM synthesis, due to its amino group, serinol can be regarded as an alkoxylation ligand and/or as a buffer compound (pK a = 12.2; Chemicalbook, 2021).…”