No abstract

Summary: We have developed the first direct, organocatalytic, bulk ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL) with solid cotton and paper cellulose as the initiators. The mild ROPs were performed without solvent, and are operationally simple, inexpensive and environmentally benign. Organic‐acid‐catalyzed heterogeneous derivatization of cellulose provides a novel route to valuable cellulose‐based biocompatible nanomaterials. The furnished polymerization products were characterized by FTIR, 1H and 13C NMR spectroscopy, MALDI‐TOF mass spectrometry and electron microscopy.Organic acid‐catalyzed ring‐opening polymerization from cellulose fiber.imageOrganic acid‐catalyzed ring‐opening polymerization from cellulose fiber.

Simple modular di- and tripeptides with a primary amine at the N-terminus catalyze the aqueous asymmetric aldol reaction between unmodified ketones and aldehydes to furnish the corresponding beta-hydroxy ketones with up to 86% ee in water and 99% ee in aqueous media.

A simple and direct method for derivatization of solid polysaccharides is presented. The novel methodology is based on the combination of organic acid-catalyzed esterification or etherification and photochemical thiol-ene click derivatization of a heterogeneous polysaccharide. The solid cellulose was "organoclick" modified with aryl, alkyl and polyester groups, respectively. The modification allows for a highly modular and metal free surface modification of solid polysaccharides.