Radiofrequency-tagged microreactors

The resin-bound trienes 83 (Scheme 11) were prepared in a similar fashion to the solution-phase studies (Sect. 2.2.2) and underwent tandem RCM resin-cleavage to liberate four macrolactones 84a,b and 85a,b in a combined yield of 52%. Although, as expected, a large amount of initiator 3 was required to effect this transformation, the procedure constituted a novel and efficient route to the epothilones which paved the way for the generation of a library of epothilone analogs. The library synthesis was achieved using the recently developed SMAR-I9 microreactors (SMART=single or multiple addressable radiofrequency tag) [25] (Scheme 12). 

Each microreactor consists of a polymer-bound substrate and a radiofrequency encoded microchip enclosed within a small porous vessel. The radiofrequency tag allows the identity of the substrate contained within each microreactor to be established readily. Using this technology, the polymer-bound substrates 86 were individually elaborated, within separate microreactors, by sequential reactions with acids 87 and alcohols 88 in a similar way to the solution-phase processes [25c]. Each of the microreactors was then subjected to the tandem RCM resin-cleavage conditions employing initiator 3. The products from each microreactor were obtained as a mixture of four compounds (89-92). The library of analogs prepared by this technique was then screened for biological activity [25c]. 

SMART Microreactors Refer to Radiofrequency tag based chemistry and Products Produced by IRORI Quantum Microchemistry, San Diego, CA. 

More recently, noninvasive coding schemes, with nonchemical tags such as radiofrequency memory units, have been used. IRORI Quantum Microchemistry s radiofrequency AccuTag-100 system aims to combine the advantages of both parallel synthesis and split and pool. The system combines glass-encapsulated microchip tags, polymer microreactors, and software, in order to produce a turnkey solution for combinatorial chemistry. 

---