Taming Highly Unstable Radical Anions and 1,4-Organodilithiums by Flow Microreactors: Controlled Reductive Dimerization of Styrenes

The reduction of styrenes with lithium arenide in a flow microreactor leads to the instantaneous generation of highly unstable radical anions that subsequently dimerize to yield the corresponding 1,4-organodilithiums. A flow reactor with fast mixing is essential for this reductive dimerization as the efficiency and selectivity are low under batch conditions. A series of styrenes undergo dimerization, and the resulting 1,4-organodilithiums are trapped with various electrophiles. Trapping with divalent electrophiles affords precursors for useful yet less accessible cyclic structures, for example, siloles from dichlorosilanes. Thus, we highlight the power of single-electron reduction of unsaturated compounds in flow microreactors for organic synthesis.

Automated summary

This study demonstrates the efficient generation of 1,4-organodilithiums through the reduction of styrenes with lithium arenide in flow microreactors. The use of a flow reactor with fast mixing is essential for achieving high efficiency and selectivity, which are low under batch conditions. The resulting 1,4-organodilithiums can react with various electrophiles to yield precursors for useful yet less accessible cyclic structures.