Poly(α‐hydroxy alkanoic acid)s Derived From α‐Amino Acids

Abstract

Biodegradable polyesters derived from hydrophobic amino acids are synthesized by various techniques, resulting in a wide range of molecular weights. The polymers are prepared via a) direct condensation with p-toluenesulfonic acid (PTSA) as catalyst, b) ring-opening polymerization (ROP) of O-carboxyanhydrides, and c) ROP of cyclic dilactones. The polymers obtained by the first method reach a molecular weight ranging from 1000 to 3000 Da, whereas those formed by the second and third method yield extended molecular weights of 15000-30000 Da. The purity of the monomers as well as their steric bulkiness are key factors affecting the polymerizability of cyclic monomers by ROP. Other parameters such as spatial ring alignment and proximity organization may also play a role.

Synthesis and properties of novel diisopropyl-functionalized polyglycolide–PEG copolymers

“…[18][19][20][21][22] All spectra for the characterizations of compound 2 and 3 can be found in supporting info section. CH proton at compound 2 shifted from 4.15 ppm to 4.73 ppm in monomer.…”

“…[18][19][20][21][22] Synthesis and the conformational aspects of poly(diisopropyl glycolide) homopolymer were performed, and the conformational aspects were evaluated by means of optical rotatory dispersion (ORD) and circular dichroism (CD). [18][19][20][21][22] Synthesis and the conformational aspects of poly(diisopropyl glycolide) homopolymer were performed, and the conformational aspects were evaluated by means of optical rotatory dispersion (ORD) and circular dichroism (CD).…”

“…[18][19][20][21][22] Synthesis and the conformational aspects of poly(diisopropyl glycolide) homopolymer were performed, and the conformational aspects were evaluated by means of optical rotatory dispersion (ORD) and circular dichroism (CD). [20][21] The polymerization kinetics, spectroscopic and thermal properties of poly(diisopropyl glycolide) were also studied. [20][21] The polymerization kinetics, spectroscopic and thermal properties of poly(diisopropyl glycolide) were also studied.…”

“…There are only a few studies related to the homopolymer of diisopropyl glycolide in the literature. [18][19][20][21][22] The synthesis of the poly(diisopropyl glycolide) homopolymer was performed, and the conformational aspects were evaluated by means of optical rotatory dispersion (ORD) and circular dichroism (CD). 18,19 Also, homopolymerization of poly(diisopropyl glycolide) was examined by varying the catalyst, temperature, and time, and the optical purity of the polymers was investigated.…”

An Atropos Biphenyl Bisphosphine Ligand with 2,2′‐tert‐Butylmethylphosphino Groups for the Rhodium‐Catalyzed Asymmetric Hydrogenation of Enol Esters

“…( R )‐2‐hydroy‐3‐phenylpropanoic acid (3 a) : The solution of hydrogenated product 2 a (70.0 mg, 0.24 mmol) in concentrated HCl (15 mL) was heated to reflux for 8 hours. After cooling down to room temperature, the reaction was extracted with DCM (15 mL×3).…”