Carbonate Couplers and Functional Cyclic Carbonates from Amino Acids and Glucosamine

Abstract

On the basis of glycerol carbonate, four coupling reagents 3a‐d were prepared. Their synthesis and characterisation, starting from glycerol carbonate 2, is described. To evaluate the differences in reactivity these couplers were reacted with valine methyl ester and the results were compared with the already known coupler 3a. Reaction conditions influenced the conversion of the couplers 3a‐d containing phenyl, 4‐nitrophenyl, imidazolyl and acetone oxime leaving groups; highest conversion and fastest reaction rates were obtained with 3b. The coupling reagents 3a and b were used for the synthesis of functional carbonate building blocks from amino acid methyl esters and glucosamine.

Isocyanate‐ and Phosgene‐Free Routes to Polyfunctional Cyclic Carbonates and Green Polyurethanes by Fixation of Carbon Dioxide

“…For example, diols are converted into cyclic carbonates by reacting them with dialkyl carbonates and urea [47][48][49][50] or directly with carbon dioxide in supercritical carbon dioxide as reaction medium. [ 14,51 ] Transesterifi cation of dialkyl carbonates with diols are catalyzed by acids and bases, [52][53][54][55][56][57] Sn catalysts like dibutyltin oxide, [ 58 ] or enzymatic catalysts. [ 59,60 ] An example for an uncatalyzed reaction is the preparation of cyclic carbonates using ethylene carbonate as an intermediate in transesterifi cation.…”

Synthesis and characterization of functional six-membered ring carbonates for the preparation of orthogonal couplers

“…To our knowledge this class of compounds was not used before as couplers for the connection of different building blocks. Important for connecting two or more building blocks selectively via carbonate couplers is, that the functional groups of the couplers have different rates for the conversion of nucleophiles [1,2]. Orthogonal reactive couplers have the advantage to connect building blocks by two not competing mechanisms.…”

“…The remaining free hydroxy group of 1 was functionalized in three different ways resulting in activated carbonic acid derivatives, which are highly reactive towards nucleophilic substitution with amines as nucleophiles [1,3,26].…”

“…In our group several difunctional carbonate couplers were developed and their selective reaction with nucleophiles was investigated (Scheme 1) [1][2][3]. Scheme 1.…”

Poly(amide urethane)s with functional/reactive side groups based on a bis-cyclic bio-based monomer/coupling agent

“…Using two different amines and one of the AA 0 dicarbonate monomers alternating copolymers can be obtained, if the two amines are added consecutively: first 0.5 equivalent of NH 2 -R 1 -NH 2 and after full conversion another 0.5 equivalent of NH 2 -R 2 -NH 2 [19][20][21][22][23][24][25][26]. The resulting hydroxyl functional polyurethanes are amorphous materials; the glass transition temperature can be adjusted in a large range; of special interest being those with 20 < T G < 50°C.…”