Conjugate substitution reaction of α-(substituted methyl)acrylates in polymer chemistry

Unsaturated polyurethanes degradable by conjugate substitution reactions with amines and carboxylate anions

“…The reversibility of the conjugate substitution reaction depends on the acidity of the liberating component and the nucleophile. 18 Therefore, the treatment of PCEs containing an acyloxy group at the allylic position with carboxylate anions should result in reversible and incomplete chain scission. Nevertheless, the chain scission of poly(conjugated ester–urethane)s was expectedly irreversible, as the conjugate substitution reaction follows a decarboxylation process.…”

“…Methacrylates carrying a leaving group, such as a halogen atom at the allylic position, undergo nucleophilic conjugated substitution reaction via an addition-elimination (S N 2 ′ ) mechanism. 17,18 Recently, we applied conjugate substitution reaction to prepare PCEs. [19][20][21] The polycondensation using dicarboxylic acid, bisphenols, and dithiols was employed under 25 °C, resulting in a variety of PCEs with high molecular weight (M n > 10 4 ).…”

Controls and Effects of Monomer Junctions and Sequences in Curable and Degradable Polyarylate Containing Acrylate Moieties

“…Methacrylate bearing a leaving group such as acyloxy and phenoxy groups at allylic position is a unique skeleton that undergoes both radical polymerization and nucleophilic conjugate substitution reactions via addition‐elimination (S N 2′) mechanism. [ 7 ] Thus, poly(conjugated ester)s (PCEs), that is, unsaturated polyesters possessing acrylate skeletons in their backbones, with leaving groups at the allylic position exhibits both thermo‐setting properties by radical polymerization and main‐chain scission by conjugate substitution. [ 8–12 ] One of the "smallest" monomers to incorporate such allyl‐substituted methacrylate skeletons is four‐membered cyclic acrylate for ring‐opening polymerization.…”

“…Methacrylate bearing a leaving group such as acyloxy and phenoxy groups at allylic position is a unique skeleton that undergoes both radical polymerization and nucleophilic conjugate substitution reactions via addition-elimination (S N 2′) mechanism. [7] Thus, poly(conjugated ester)s (PCEs), that is, unsaturated polyesters possessing acrylate skeletons in their the latter stage. Notably, 0.50 equimolar of 2 yielded the corresponding diester 3 as a major product (Entry 4, Figure S3, Supporting Information).…”

Chemical reaction networks based on conjugate additions on β′-substituted Michael acceptors

“…To overcome this problem, the group of R. Lawton developed a special class of Michael acceptors that carry a leaving group in the β′-position (Scheme 2C). 65 They are also commonly called α-substituted MAs, 66,67 however we will refer to them as β′-substituted to put emphasis on the presence of a leaving group in this position and distinguish them from other α-substituted species that cannot undergo the same reactions. Although these compounds also undergo the typical 1,4-addition reactions, the leaving group in β′-position enables an elimination reaction to take place upon conjugate addition of the nucleophile.…”