Chitosan-Microreactor: A Versatile Approach for Heterogeneous Organic Synthesis in Microfluidics

Microreactors have been proven to be efficient tools for a variety of homogeneous organic transformations due to their mixing efficiency, which results in very fast reactions, better heat and mass transfer, and simple scale‐up. However, in heterogeneous catalytic reactions each catalyst needs an individual substrate as support. Herein, a versatile approach to immobilize metal catalysts on chitosan as a common substrate is presented. Chitosan, accommodating many metal catalysts, is grafted onto the microchannel surface as nanobrush. The versatility, catalytic efficiency, and stability/durability of the microreactor are demonstrated for a number of organic transformations involving various metal compounds as catalysts. Swallowed chitosan fixes metals: A general‐purpose platform has been devised for the synthesis of a library of compounds in the form of a microreactor using a facile method: chitosan is immobilized on a microreactor channel as nanobrush. Using this method, a variety of metal compounds/metals can be immobilized on chitosan; used as a versatile substrate, robust and excellent catalytic activity can be achieved.