One-pot, additive-free preparation of functionalized polyurethanes via amine–thiol–ene conjugation

Abstract

A straightforward, isocyanate-free methodology for the synthesis of functionalized 8 polyurethanes, based on amine-thiol-ene conjugation, was elaborated. Aminolysis of a readily 9 available AB'-urethane monomer, containing both an acrylate (A) and a thiolactone unit (B'),

Two tandem multicomponent reactions for the synthesis of sequence-defined polymers

“…On the other hand, the multicomponent reaction between a thiolactone, an amine and an alkene, which is an amine-thiol-ene conjugation, can be carried out with high efficiency under mild conditions. The reaction has high functional group tolerance as evidenced by Du Prez's [29][30][31][32] and our experiments [25,33,34], and is therefore a very promising method for the synthesis of functional and sequence-controlled polymers.…”

One-Pot Double Modification of Polymers Based on Thiolactone Chemistry

“…The kinetic profile and outcome of the nucleophilic amine-thiol-ene conjugation through a series of model reactions involving n-propylamine, γ-thiobutyrolactone, and n-butyl acrylate has also been investigated [51]. The major conclusion from this model study was that, as anticipated, aminolysis is the rate-determining step.…”

“…Upon aminolysis, this monomer forms a reactive thiol-acrylate (AB monomer), which is consumed in the same medium by a conjugate addition [51]. This strategy offers an easy-to-perform, one-pot method for the synthesis of functionalized polyaddition polymers.…”

“…Although this unwanted secondary reaction can be avoided when employing one-pot thiolactonebased reactions, such as nucleophilic amine-thiol-ene conjugation, it still requires careful monitoring. Sometimes the corresponding disulfide is the major adduct of a ring opening of the thiolactone precursor, especially in the absence of a thiol scavenger and in the presence of a larger excess of primary amine during aminolysis [51]. At present, we still do not fully understand the parameters that influence the extent of disulfide formation during aminolysis of a thiolactone, compromising the prevention, prediction, and control of this event.…”

“…Hence, the influence of the nature of the primary amine in the ring opening of thiolactones was studied. Kinetic screening of the lysis of γ-thiobutyrolactone in the presence of different (functional) primary amines was performed (Scheme 4) [51]. Generally, the aminolysis of thiolactones can be described by second-order kinetics [116].…”