Colorimetric Tools for Solid-Phase Organic Synthesis

New Cellulose-Supported Reagent: A Sustainable Approach to Guanidines

[reaction: see text] A new cellulose-supported reagent for the synthesis of guanidine in aqueous medium is reported starting from commercially available functionalized cellulose beads. Primary and secondary amines, anilines, and amino acids were transformed to the corresponding guanidines in high yields and under very mild conditions.

A New Polymer-Supported Reagent for the Synthesis of β-Lactams in Solution

A modified Mukaiyama reagent was prepared on a PS-DVB resin. This reagent was used for the preparation of beta-lactams, using the Staudinger reaction. The products were obtained by generating the ketene from a carboxylic acid under sonication with the resin followed by reaction with the imine. Excess of the imine was removed by reduction followed by acid scavenging.