The use of toxic or hazardous reagents

In addition to the seven deoxygenation and dehalogenation reactions demonstrated, the authors adapted the methodology to the hydrosilyla-tion of a series of alkynes and alkenes. To conduct such reactions, a premixed solution of the alkyne or alkene (1.00 M), tris(trimethylsilyl) silane 61 (1.2M) and AIBN 62 (10mol%) in toluene was passed through the heated microreactor (130 °C) at a flow rate of 200 jilmin-1, affording a residence time of 5 min. 

As Table 5 illustrates, compared to batchwise reactions the increased heat and mass transfer obtained within the microfluidic reactor afforded enhanced cis/trans selectivity for reactions employing alkynes and more generically a dramatic reduction in reaction time (cf. conventional batch reactions). 

The reaction of organolithium compounds with carbon-based electrophiles represents one of the most useful synthetic methodologies for the formation of C-C bonds as such, several groups have investigated these reactions in microstructured devices. 

As Table 10 illustrates, using this approach the authors were able to rapidly optimize the reaction conditions, obtaining the target 82 in 91% yield when employing 2 eq. of fenchone (80) and n-BuLi 74. In all cases only a single diastereomer was observed and the authors found that conducting the reaction at 0 °C resulted in a mere 3% reduction in yield. Furthermore, the reaction conditions were found to be suitable for a range of aliphatic/aromatic ketones and brominated compounds. 

Conducting reactions at 48 °C, the formation of oxirane occurred rapidly, indicating that the deprotonation of styrene oxide 83 is rapid however, this was accompanied by decomposition of the oxiranyl anion 87. Reducing the reactor temperature to —78 °C, the anion 87 was found to be stable for up to 25 s, enabling efficient reaction with a series of electrophiles to afford the respective substituted epoxide in high yield, as illustrated in Table 11. 

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