Base-promoted alkylation of P(O)OH compounds with amines via C–N bond cleavage

Recent Progress on Cellulose-Based Ionic Compounds for Biomaterials

Glycans play important roles in all major kingdoms of organisms, such as archea, bacteria, fungi, plants, and animals. Cellulose, the most abundant polysaccharide on the Earth, plays a predominant role for mechanical stability in plants, and finds a plethora of applications by humans. Beyond traditional use, biomedical application of cellulose becomes feasible with advances of soluble cellulose derivatives with diverse functional moieties along the backbone and modified nanocellulose with versatile functional groups on the surface due to the native features of cellulose as both cellulose chains and supramolecular ordered domains as extractable nanocellulose. With the focus on ionic cellulose-based compounds involving both these groups primarily for biomedical applications, a brief introduction about glycoscience and especially native biologically active glycosaminoglycans with specific biomedical application areas on humans is given, which inspires further development of bioactive compounds from glycans. Then, both polymeric cellulose derivatives and nanocellulose-based compounds synthesized as versatile biomaterials for a large variety of biomedical applications, such as for wound dressings, controlled release, encapsulation of cells and enzymes, and tissue engineering, are separately described, regarding the diverse routes of synthesis and the established and suggested applications for these highly interesting materials.

Recent Progress in the Selective Functionalization of P(O)-OH Bonds

As we all know, organic phosphorus compounds have high application values in chemical industries. Compared with traditional compounds with P-X (X = Cl, Br, I) and P-H bonds, phosphorylation reagents containing P(O)-OH bonds are stable, environmentally friendly, and inexpensive. However, in recent years, there have been few studies on the selective functionalization of P(O)-OH bonds for the fabrication of P-C and P-Z bonds. In general, four-coordinated P(O)-OH compounds have reached coordination saturation due to the phosphorus atom center, but cannot evolve the phosphorus coordination center through intra-molecular tautomerization; however, the weak coordination effects between the P=O bond and transition metals can be utilized to activate P(O)-OH bonds. This review highlights the most important recent contributions toward the selective functionalization of P(O)-OH bonds via cyclization/cross coupling/esterification reactions using transition metals or small organic molecules as the catalyst.

Selective Transesterification of 2,2,2-Trifluoroethyl Phosphates: Synthesis of Mixed Unsymmetrical Phosphates

A selective transesterification starting with tris(2,2,2-trifluoroethyl) phosphate has been developed. This method involves a three-step substitution for 2,2,2-trifluoroethoxy groups and enables the facile synthesis of mixed unsymmetric phosphate triesters from three different alcohols. The substitution of the trifluoroethoxy group at the phosphorus proceeds selectively in the presence of DBU or lithium alkoxides. This method can be applied for the preparation of phospholipids.