The alternating copolymerization of epoxides and cyclic anhydrides is an increasingly popular route to aliphatic polyesters that are of interest as biodegradable replacements for petroleum-based polymers and for use in the biomedical field. However, broad and bimodal molecular weight distributions in these polymerizations continues to be an issue, limiting synthesis of multiblock copolymers. By...

Biodegradable polymers are a promising sustainable alternative to conventional petroleum-based and have attracted recent extensive research interest due their potential environmental friendliness sustainability. Among them, aliphatic polyesters polycarbonates the most extensively studied ones. The metal-catalyzed ring-opening polymerization (ROP) of cyclic esters copolymerization (ROCOP) epoxid...

Depending on reaction conditions, the phosphonylation of N-alkylacetamides with H3PO3-P C I3 in B-HC1 media (B = Py, Bu3N) gives either l-alkylaminoethylidene-l,l-bisphosphonic acids (la—e) or previously unknown l-alkylaminobutane-l,l,3,3-tetrayl-tetrakisphosphonic dianhydrides (2a-e). The latter convert into monocyclic forms (3a-e) under mild acidic hydrolysis. Acyclic forms (4a-e) cannot be i...

The construction of carbon-carbon bonds, particularly with concomitant control of newly formed asymmetric centers, is of paramount importance for the development of synthetic routes to complex organic molecules. While cross-coupling reactions for the generation of sp(2) carbon centers are well established, similar methodology for the formation and control of sp(3)-hydridized carbon stereocenter...

The oxidation of isatins at room temperature, using the cheap and environmentally friendly urea-hydrogen peroxide complex and ultrasonic irradiation, has been investigated. The ultrasonic irradiation dramatically reduces the reaction time. With easy and reproducible reaction procedures, different isatoic anhydrides were obtained in excellent yield and with high purity.

A practical protocol is developed to directly provide chiral α-acyloxyphosphonates and α-hydroxyphosphonates from (±)-α-hydroxyphosphonates utilizing the transacylation process to generate the mixed anhydrides from acid components and pivalic anhydride in the presence of organocatalysts (s-value = 33-518).