Synthesis of halogen-substituted borolanes and 2,3-dihydro-1H-boroles by reactions of aluminacarbocycles with boron trichloride and boron tribromide

A selective procedure has been developed for the synthesis of 1-chloro(bromo)-substituted borolanes and 2,3-dihydro-1H-boroles by reaction of aluminacarbocycles with boron trihalides BX3 (X = Cl, Br). 3-Substituted 1-chloro(bromo)borolanes and 2,3-dihydro-1H-boroles have been isolated as individual substances, and their structure has been determined.