A highly elastic absorbable monofilament suture fabricated from poly(3-hydroxybutyrate-co-4-hydroxybutyrate).

To address the growing demand for more elastic sutures free from unwanted knot loosening, we fabricated an absorbable monofilament suture from poly(3-hydroxybutyrate-co-4-hydroxybutyrate) and subjected it to physical property characterization and performance evaluation (in vitro and in vivo degradability tests and a porcine abdominal wall suture test). As this flexible, highly stretchable, and difficult-to-untie suture exhibited additional advantages of small knot size and medium to long-term bioabsorbability, it was concluded to be a safe alternative to existing monofilament sutures, with far-reaching potential applications.

Desymmetrization of aziridine with malononitrile using cinchona alkaloid amide/zinc(ii) catalysts.

The catalytic enantioselective desymmetrization of aziridines with malononitrile has been developed. Good yield and enantioselectivity were obtained by using cinchona alkaloid amide/Zn(ii) catalysts. The obtained product can be converted to ß-aminoester, ß-aminoamide and triamide compounds.

Enantioselective Oxidative Ring-Opening Reaction of Aziridines with α-Nitroesters Using Cinchona Alkaloid Amide/Nickel(II) Catalysts.

The enantioselective oxidative ring-opening reaction of aziridines with α-nitroacetates has been developed. Good yields and enantioselectivity were observed for the reaction of various aziridines using a novel cinchona alkaloid amide/NiBr2 catalyst. Both enantiomers of products could be obtained by using pseudoenantiomeric chiral catalysts. This process offers an efficient route for the synthesis of α-aminoketones.

Direct asymmetric Mannich-type reaction of α-isocyanoacetates with ketimines using cinchona alkaloid/copper(II) catalysts.

The enantioselective direct Mannich-type reaction of ketimines with α-isocyanoacetates has been developed. Excellent yields and enantioselectivity were observed for the reaction of various ketimines and α-isocyanoacetates using cinchona alkaloid/Cu(OTf)2 and a base. Both enantiomers of the products could be obtained by using pseudoenantiomeric chiral catalysts. This process offers an efficient route for the synthesis of α,ß-diamino acids.

Cinchona alkaloid amides/dialkylzinc catalyzed enantioselective desymmetrization of aziridines with phosphites.

The first highly enantioselective desymmetrization of aziridines with phosphites has been developed. Excellent yields and enantioselectivities were observed for the reaction with various aziridines using a new class of readily accessible chiral catalysts derived from 9-amino-9-deoxy-epi-cinchona alkaloids. In studies probing the reaction mechanism, we observed some complexes for the cinchona alkaloid amide-Zn(II) by ESI-MS analysis.