The exploitation of microchannel reactors for rapid, facile organic synthesis is an area of research currently enjoying a lot of attention; however the preparation of catalyst-installed microfluidic devices remains a challenge.

Yasuhiro Uozumi and colleagues, in a collaborative project between RIKEN in Hirosawa and the Institute for Molecular Science, Myodaiji, have developed an existing technique for catalyst immobilisation to create microchannels which contain a catalytic membrane. This method enables the preparation of palladium embedded membranes, which are formed via a 'ship in a bottle' technique, at the laminar flow interface. This instantly creates a multiple phase reaction system, where the catalytic and heterogeneous properties are conferred in one step.

This membrane is capable of mediating the coupling of allylic esters with allylic boron reagents after only one second of residence in the microdevice.

Uozumi envisages that this platform could be adapted for the preparation of radiopharmaceuticals, which need to be prepared quickly to minimise the loss of efficacy via radioactive decay. 

Looking to the future, Uozomi, aims to produce a whole host of catalytic membrane-installed microdevices that could be used for a range of reaction types; he sees the next challenge to be the installation of a chiral catalytic membrane into a microdevice, for the facilitation of asymmetric catalysis.

Katie Dryden-Holt