|Collins & Glorius have a thing or two to say on the topic of establishing functional group tolerance in reaction screening (DOI). The traditional method - test new reaction on xx number of substrates having various functional groups - is too slow and too non-informational. The solution: decouple functional group from reactive centre by simply having a model reaction taking place in presence of an additive containing a particular functional group. |
Collins & Glorius have put the idea to the test with a simple Buchwald-Hartwig reaction between 3-bromoanisole and morpholine. Repeating this reaction with a multitude of additives can be automated, GC analysis included.
Additives not found to interfere (consumed or inhibiting or both) were simple alkenes, nitriles and for example benzylpyrrole. Interfering additives thus unearthed were terminal alkynes, alcohols and n-methylpyrrole.
Nice concept but entirely new? This blog has been featuring lazy chemistry as envisioned by Robbins and Hartwig in a 2011 article. This blog does not understand the following claim made in the article: " to the best of our knowledge, no discrete method for assessing the stability of chemical functionality or motifs, including heterocycles (...) has been reported ". Chemists have been doing this for 100 years and with much enthusiasm? The Robbins & Hartwig article gets a mention but only to credit them for the batch calibration technique used.