Discovery of unexpectedly complex reaction pathways for the Knorr pyrazole synthesis via transient flow

Abstract

Kinetic data for reactions between phenyl hydrazine and 1,3-diketones (Knorr pyrazole synthesis) were acquired by using transient flow methods. Supported by further spectroscopic and mass spectrometry data, a microkinetic model...

An efficient multiparameter method for the collection of chemical reaction data via ‘one-pot’ transient flow

“…A previously described flow reactor system 3 was modified for this work (Fig. S1†), by integrating a (GC) oven to implement precise temperature ramps, and an on-line HPLC system to monitor and quantify multiple reaction species in an accessible manner.…”

Quid Pro Flow

“…Sensitive analytical methods have also enabled extremely high-throughput droplet screening in flow, ,− only possible because robust MS data can now be obtained from nanogram quantities. Combining such experiments with autonomous algorithms offers an extremely powerful route to reaction screening and optimization; here, the backlog becomes data processing and, potentially, generating new hypotheses to test.…”

“…Typically, such measurements are taken under steady state conditions to allow for stable measurement. However, methods have been recently reported that use transient flow measurements without reaching steady state; parameters are continually varied to rapidly explore the impact of, e.g., temperature on kinetics. − This powerful technique dramatically shortens the experimental time needed to extract useful information about a process, resulting in many data points from a single run …”

Dynamic experiments in flow accelerate reaction network definition in a complex hydrogenation using catalytic static mixers

“…[12][13][14][15] Dynamic experiments have been developed and demonstrated by various groups, but, thus far, used exclusively for homogeneous reactions. [16][17][18][19][20][21][22][23][24] Application of this technique to heterogeneously-catalyzed gas-liquid reactions, however, has not yet been investigated.…”