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Anionic polymerization of styrene using sec-BuLi as an initiator was conducted in a microflow system. A high level of molecular-weight distribution control was achieved under easily accessible conditions, such as at 0 °C (M w /M n ) 1.08) and 24 °C (M w /M n ) 1.10). The polymerization of styrene derivatives having silyl, methoxy, silyloxy, alkynyl, and alkylthio groups on the benzene ring also took place in a highly controlled manner using sec-BuLi as an initiator. The end functionalization using chlorosilanes and block copolymerization were also achieved in microflow systems. The end functionalization with dichlorodimethylsilane led to the formation of a chlorosilane having a single polymer chain on silicon. The subsequent reaction with another active polymer chain gave block copolymers having two different polymer chains on a silicon core.

We found that a flow microreactor system enables the generation of a configurationally unstable chiral organolithium intermediate and allows for its use in a reaction with an electrophile before it epimerizes. Based on this method, the enantioselective carbolithiation of conjugated enynes followed by the reaction with electrophiles was accomplished to obtain enantioenriched chiral allenes.

A micro flow system consisting of micromixers and microtube reactors provides an effective method for the introduction of two electrophiles onto p-, m-, and o-dibromobenzenes. The Br-Li exchange reaction of p-dibromobenzene with nBuLi can be conducted by using the micro flow system at 20 degrees C, although much lower temperatures (< -48 degrees C) are needed for a batch reaction. The resulting p-bromophenyllithium was allowed to react with an electrophile in the micro flow system at 20 degrees C. The p-substituted bromobenzene thus obtained was subjected to a second Br-Li exchange reaction followed by reaction with a second electrophile at 20 degrees C in one flow. A similar transformation can be carried out with m-dibromobenzene by using the micro flow system. However, the Br-Li exchange reaction of o-dibromobenzene followed by reaction with an electrophile should be conducted at -78 degrees C to avoid benzyne formation. The second Br-Li exchange reaction followed by reaction with an electrophile can be carried out at 0 degrees C. By using the present method, a variety of p-, m-, and o-disubstituted benzenes were synthesized in one flow at much higher temperatures than are required for conventional batch reactions.

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